From 6b33ec5b2e4b6921dda25ca35f91241f19023e88 Mon Sep 17 00:00:00 2001 From: Eric Norum Date: Mon, 12 Mar 2001 10:42:09 +0000 Subject: Useful add-on libraries --- readline-4.2/doc/history.3 | 639 ++++++++++++ readline-4.2/doc/hstech.texinfo | 549 +++++++++++ readline-4.2/doc/rltech.texinfo | 2083 +++++++++++++++++++++++++++++++++++++++ 3 files changed, 3271 insertions(+) create mode 100644 readline-4.2/doc/history.3 create mode 100644 readline-4.2/doc/hstech.texinfo create mode 100644 readline-4.2/doc/rltech.texinfo diff --git a/readline-4.2/doc/history.3 b/readline-4.2/doc/history.3 new file mode 100644 index 0000000..93702b4 --- /dev/null +++ b/readline-4.2/doc/history.3 @@ -0,0 +1,639 @@ +.\" +.\" MAN PAGE COMMENTS to +.\" +.\" Chet Ramey +.\" Information Network Services +.\" Case Western Reserve University +.\" chet@ins.CWRU.Edu +.\" +.\" Last Change: Tue Mar 6 12:50:54 EST 2001 +.\" +.TH HISTORY 3 "2001 Mar 6" "GNU History 4.2" +.\" +.\" File Name macro. This used to be `.PN', for Path Name, +.\" but Sun doesn't seem to like that very much. +.\" +.de FN +\fI\|\\$1\|\fP +.. +.ds lp \fR\|(\fP +.ds rp \fR\|)\fP +.\" FnN return-value fun-name N arguments +.de Fn1 +\fI\\$1\fP \fB\\$2\fP \\*(lp\fI\\$3\fP\\*(rp +.br +.. +.de Fn2 +.if t \fI\\$1\fP \fB\\$2\fP \\*(lp\fI\\$3,\|\\$4\fP\\*(rp +.if n \fI\\$1\fP \fB\\$2\fP \\*(lp\fI\\$3, \\$4\fP\\*(rp +.br +.. +.de Fn3 +.if t \fI\\$1\fP \fB\\$2\fP \\*(lp\fI\\$3,\|\\$4,\|\\$5\fP\|\\*(rp +.if n \fI\\$1\fP \fB\\$2\fP \\*(lp\fI\\$3, \\$4, \\$5\fP\\*(rp +.br +.. +.de Vb +\fI\\$1\fP \fB\\$2\fP +.br +.. +.SH NAME +history \- GNU History Library +.SH COPYRIGHT +.if t The GNU History Library is Copyright \(co 1989-2001 by the Free Software Foundation, Inc. +.if n The GNU History Library is Copyright (C) 1989-2001 by the Free Software Foundation, Inc. +.SH DESCRIPTION +Many programs read input from the user a line at a time. The GNU +History library is able to keep track of those lines, associate arbitrary +data with each line, and utilize information from previous lines in +composing new ones. +.PP +.SH "HISTORY EXPANSION" +.PP +The history library supports a history expansion feature that +is identical to the history expansion in +.BR bash. +This section describes what syntax features are available. +.PP +History expansions introduce words from the history list into +the input stream, making it easy to repeat commands, insert the +arguments to a previous command into the current input line, or +fix errors in previous commands quickly. +.PP +History expansion is usually performed immediately after a complete line +is read. +It takes place in two parts. +The first is to determine which line from the history list +to use during substitution. +The second is to select portions of that line for inclusion into +the current one. +The line selected from the history is the \fIevent\fP, +and the portions of that line that are acted upon are \fIwords\fP. +Various \fImodifiers\fP are available to manipulate the selected words. +The line is broken into words in the same fashion as \fBbash\fP +does when reading input, +so that several words that would otherwise be separated +are considered one word when surrounded by quotes (see the +description of \fBhistory_tokenize()\fP below). +History expansions are introduced by the appearance of the +history expansion character, which is \^\fB!\fP\^ by default. +Only backslash (\^\fB\e\fP\^) and single quotes can quote +the history expansion character. +.SS Event Designators +.PP +An event designator is a reference to a command line entry in the +history list. +.PP +.PD 0 +.TP +.B ! +Start a history substitution, except when followed by a +.BR blank , +newline, = or (. +.TP +.B !\fIn\fR +Refer to command line +.IR n . +.TP +.B !\-\fIn\fR +Refer to the current command line minus +.IR n . +.TP +.B !! +Refer to the previous command. This is a synonym for `!\-1'. +.TP +.B !\fIstring\fR +Refer to the most recent command starting with +.IR string . +.TP +.B !?\fIstring\fR\fB[?]\fR +Refer to the most recent command containing +.IR string . +The trailing \fB?\fP may be omitted if +.I string +is followed immediately by a newline. +.TP +.B \d\s+2^\s-2\u\fIstring1\fP\d\s+2^\s-2\u\fIstring2\fP\d\s+2^\s-2\u +Quick substitution. Repeat the last command, replacing +.I string1 +with +.IR string2 . +Equivalent to +``!!:s/\fIstring1\fP/\fIstring2\fP/'' +(see \fBModifiers\fP below). +.TP +.B !# +The entire command line typed so far. +.PD +.SS Word Designators +.PP +Word designators are used to select desired words from the event. +A +.B : +separates the event specification from the word designator. +It may be omitted if the word designator begins with a +.BR ^ , +.BR $ , +.BR * , +.BR \- , +or +.BR % . +Words are numbered from the beginning of the line, +with the first word being denoted by 0 (zero). +Words are inserted into the current line separated by single spaces. +.PP +.PD 0 +.TP +.B 0 (zero) +The zeroth word. For the shell, this is the command +word. +.TP +.I n +The \fIn\fRth word. +.TP +.B ^ +The first argument. That is, word 1. +.TP +.B $ +The last argument. +.TP +.B % +The word matched by the most recent `?\fIstring\fR?' search. +.TP +.I x\fB\-\fPy +A range of words; `\-\fIy\fR' abbreviates `0\-\fIy\fR'. +.TP +.B * +All of the words but the zeroth. This is a synonym +for `\fI1\-$\fP'. It is not an error to use +.B * +if there is just one +word in the event; the empty string is returned in that case. +.TP +.B x* +Abbreviates \fIx\-$\fP. +.TP +.B x\- +Abbreviates \fIx\-$\fP like \fBx*\fP, but omits the last word. +.PD +.PP +If a word designator is supplied without an event specification, the +previous command is used as the event. +.SS Modifiers +.PP +After the optional word designator, there may appear a sequence of +one or more of the following modifiers, each preceded by a `:'. +.PP +.PD 0 +.PP +.TP +.B h +Remove a trailing file name component, leaving only the head. +.TP +.B t +Remove all leading file name components, leaving the tail. +.TP +.B r +Remove a trailing suffix of the form \fI.xxx\fP, leaving the +basename. +.TP +.B e +Remove all but the trailing suffix. +.TP +.B p +Print the new command but do not execute it. +.TP +.B q +Quote the substituted words, escaping further substitutions. +.TP +.B x +Quote the substituted words as with +.BR q , +but break into words at +.B blanks +and newlines. +.TP +.B s/\fIold\fP/\fInew\fP/ +Substitute +.I new +for the first occurrence of +.I old +in the event line. Any delimiter can be used in place of /. The +final delimiter is optional if it is the last character of the +event line. The delimiter may be quoted in +.I old +and +.I new +with a single backslash. If & appears in +.IR new , +it is replaced by +.IR old . +A single backslash will quote the &. If +.I old +is null, it is set to the last +.I old +substituted, or, if no previous history substitutions took place, +the last +.I string +in a +.B !?\fIstring\fR\fB[?]\fR +search. +.TP +.B & +Repeat the previous substitution. +.TP +.B g +Cause changes to be applied over the entire event line. This is +used in conjunction with `\fB:s\fP' (e.g., `\fB:gs/\fIold\fP/\fInew\fP/\fR') +or `\fB:&\fP'. If used with +`\fB:s\fP', any delimiter can be used +in place of /, and the final delimiter is optional +if it is the last character of the event line. +.PD +.SH "PROGRAMMING WITH HISTORY FUNCTIONS" +This section describes how to use the History library in other programs. +.SS Introduction to History +.PP +The programmer using the History library has available functions +for remembering lines on a history list, associating arbitrary data +with a line, removing lines from the list, searching through the list +for a line containing an arbitrary text string, and referencing any line +in the list directly. In addition, a history \fIexpansion\fP function +is available which provides for a consistent user interface across +different programs. +.PP +The user using programs written with the History library has the +benefit of a consistent user interface with a set of well-known +commands for manipulating the text of previous lines and using that text +in new commands. The basic history manipulation commands are +identical to +the history substitution provided by \fBbash\fP. +.PP +If the programmer desires, he can use the Readline library, which +includes some history manipulation by default, and has the added +advantage of command line editing. +.PP +Before declaring any functions using any functionality the History +library provides in other code, an application writer should include +the file +.FN +in any file that uses the +History library's features. It supplies extern declarations for all +of the library's public functions and variables, and declares all of +the public data structures. + +.SS History Storage +.PP +The history list is an array of history entries. A history entry is +declared as follows: +.PP +.Vb "typedef void *" histdata_t; +.PP +.nf +typedef struct _hist_entry { + char *line; + histdata_t data; +} HIST_ENTRY; +.fi +.PP +The history list itself might therefore be declared as +.PP +.Vb "HIST_ENTRY **" the_history_list; +.PP +The state of the History library is encapsulated into a single structure: +.PP +.nf +/* + * A structure used to pass around the current state of the history. + */ +typedef struct _hist_state { + HIST_ENTRY **entries; /* Pointer to the entries themselves. */ + int offset; /* The location pointer within this array. */ + int length; /* Number of elements within this array. */ + int size; /* Number of slots allocated to this array. */ + int flags; +} HISTORY_STATE; +.fi +.PP +If the flags member includes \fBHS_STIFLED\fP, the history has been +stifled. +.SH "History Functions" +.PP +This section describes the calling sequence for the various functions +exported by the GNU History library. +.SS Initializing History and State Management +This section describes functions used to initialize and manage +the state of the History library when you want to use the history +functions in your program. + +.Fn1 void using_history void +Begin a session in which the history functions might be used. This +initializes the interactive variables. + +.Fn1 "HISTORY_STATE *" history_get_history_state void +Return a structure describing the current state of the input history. + +.Fn1 void history_set_history_state "HISTORY_STATE *state" +Set the state of the history list according to \fIstate\fP. + +.SS History List Management + +These functions manage individual entries on the history list, or set +parameters managing the list itself. + +.Fn1 void add_history "const char *string" +Place \fIstring\fP at the end of the history list. The associated data +field (if any) is set to \fBNULL\fP. + +.Fn1 "HIST_ENTRY *" remove_history "int which" +Remove history entry at offset \fIwhich\fP from the history. The +removed element is returned so you can free the line, data, +and containing structure. + +.Fn3 "HIST_ENTRY *" replace_history_entry "int which" "const char *line" "histdata_t data" +Make the history entry at offset \fIwhich\fP have \fIline\fP and \fIdata\fP. +This returns the old entry so you can dispose of the data. In the case +of an invalid \fIwhich\fP, a \fBNULL\fP pointer is returned. + +.Fn1 void clear_history "void" +Clear the history list by deleting all the entries. + +.Fn1 void stifle_history "int max" +Stifle the history list, remembering only the last \fImax\fP entries. + +.Fn1 int unstifle_history "void" +Stop stifling the history. This returns the previous amount the +history was stifled. The value is positive if the history was +stifled, negative if it wasn't. + +.Fn1 int history_is_stifled "void" +Returns non-zero if the history is stifled, zero if it is not. + +.SS Information About the History List + +These functions return information about the entire history list or +individual list entries. + +.Fn1 "HIST_ENTRY **" history_list "void" +Return a \fBNULL\fP terminated array of \fIHIST_ENTRY *\fP which is the +current input history. Element 0 of this list is the beginning of time. +If there is no history, return \fBNULL\fP. + +.Fn1 int where_history "void" +Returns the offset of the current history element. + +.Fn1 "HIST_ENTRY *" current_history "void" +Return the history entry at the current position, as determined by +\fBwhere_history()\fP. If there is no entry there, return a \fBNULL\fP +pointer. + +.Fn1 "HIST_ENTRY *" history_get "int offset" +Return the history entry at position \fIoffset\fP, starting from +\fBhistory_base\fP. +If there is no entry there, or if \fIoffset\fP +is greater than the history length, return a \fBNULL\fP pointer. + +.Fn1 int history_total_bytes "void" +Return the number of bytes that the primary history entries are using. +This function returns the sum of the lengths of all the lines in the +history. + +.SS Moving Around the History List + +These functions allow the current index into the history list to be +set or changed. + +.Fn1 int history_set_pos "int pos" +Set the current history offset to \fIpos\fP, an absolute index +into the list. +Returns 1 on success, 0 if \fIpos\fP is less than zero or greater +than the number of history entries. + +.Fn1 "HIST_ENTRY *" previous_history "void" +Back up the current history offset to the previous history entry, and +return a pointer to that entry. If there is no previous entry, return +a \fBNULL\fP pointer. + +.Fn1 "HIST_ENTRY *" next_history "void" +Move the current history offset forward to the next history entry, and +return the a pointer to that entry. If there is no next entry, return +a \fBNULL\fP pointer. + +.SS Searching the History List + +These functions allow searching of the history list for entries containing +a specific string. Searching may be performed both forward and backward +from the current history position. The search may be \fIanchored\fP, +meaning that the string must match at the beginning of the history entry. + +.Fn2 int history_search "const char *string" "int direction" +Search the history for \fIstring\fP, starting at the current history offset. +If \fIdirection\fP is less than 0, then the search is through +previous entries, otherwise through subsequent entries. +If \fIstring\fP is found, then +the current history index is set to that history entry, and the value +returned is the offset in the line of the entry where +\fIstring\fP was found. Otherwise, nothing is changed, and a -1 is +returned. + +.Fn2 int history_search_prefix "const char *string" "int direction" +Search the history for \fIstring\fP, starting at the current history +offset. The search is anchored: matching lines must begin with +\fIstring\fP. If \fIdirection\fP is less than 0, then the search is +through previous entries, otherwise through subsequent entries. +If \fIstring\fP is found, then the +current history index is set to that entry, and the return value is 0. +Otherwise, nothing is changed, and a -1 is returned. + +.Fn3 int history_search_pos "const char *string" "int direction" "int pos" +Search for \fIstring\fP in the history list, starting at \fIpos\fP, an +absolute index into the list. If \fIdirection\fP is negative, the search +proceeds backward from \fIpos\fP, otherwise forward. Returns the absolute +index of the history element where \fIstring\fP was found, or -1 otherwise. + +.SS Managing the History File +The History library can read the history from and write it to a file. +This section documents the functions for managing a history file. + +.Fn1 int read_history "const char *filename" +Add the contents of \fIfilename\fP to the history list, a line at a time. +If \fIfilename\fP is \fBNULL\fP, then read from \fI~/.history\fP. +Returns 0 if successful, or \fBerrno\fP if not. + +.Fn3 int read_history_range "const char *filename" "int from" "int to" +Read a range of lines from \fIfilename\fP, adding them to the history list. +Start reading at line \fIfrom\fP and end at \fIto\fP. +If \fIfrom\fP is zero, start at the beginning. If \fIto\fP is less than +\fIfrom\fP, then read until the end of the file. If \fIfilename\fP is +\fBNULL\fP, then read from \fI~/.history\fP. Returns 0 if successful, +or \fBerrno\fP if not. + +.Fn1 int write_history "const char *filename" +Write the current history to \fIfilename\fP, overwriting \fIfilename\fP +if necessary. +If \fIfilename\fP is \fBNULL\fP, then write the history list to \fI~/.history\fP. +Returns 0 on success, or \fBerrno\fP on a read or write error. + + +.Fn2 int append_history "int nelements" "const char *filename" +Append the last \fInelements\fP of the history list to \fIfilename\fP. +If \fIfilename\fP is \fBNULL\fP, then append to \fI~/.history\fP. +Returns 0 on success, or \fBerrno\fP on a read or write error. + +.Fn2 int history_truncate_file "const char *filename" "int nlines" +Truncate the history file \fIfilename\fP, leaving only the last +\fInlines\fP lines. +If \fIfilename\fP is \fBNULL\fP, then \fI~/.history\fP is truncated. +Returns 0 on success, or \fBerrno\fP on failure. + +.SS History Expansion + +These functions implement history expansion. + +.Fn2 int history_expand "char *string" "char **output" +Expand \fIstring\fP, placing the result into \fIoutput\fP, a pointer +to a string. Returns: +.RS +.PD 0 +.TP +0 +If no expansions took place (or, if the only change in +the text was the removal of escape characters preceding the history expansion +character); +.TP +1 +if expansions did take place; +.TP +-1 +if there was an error in expansion; +.TP +2 +if the returned line should be displayed, but not executed, +as with the \fB:p\fP modifier. +.PD +.RE +If an error ocurred in expansion, then \fIoutput\fP contains a descriptive +error message. + +.Fn3 "char *" get_history_event "const char *string" "int *cindex" "int qchar" +Returns the text of the history event beginning at \fIstring\fP + +\fI*cindex\fP. \fI*cindex\fP is modified to point to after the event +specifier. At function entry, \fIcindex\fP points to the index into +\fIstring\fP where the history event specification begins. \fIqchar\fP +is a character that is allowed to end the event specification in addition +to the ``normal'' terminating characters. + +.Fn1 "char **" history_tokenize "const char *string" +Return an array of tokens parsed out of \fIstring\fP, much as the +shell might. +The tokens are split on the characters in the +\fBhistory_word_delimiters\fP variable, +and shell quoting conventions are obeyed. + +.Fn3 "char *" history_arg_extract "int first" "int last" "const char *string" +Extract a string segment consisting of the \fIfirst\fP through \fIlast\fP +arguments present in \fIstring\fP. Arguments are split using +\fBhistory_tokenize()\fP. + +.SS History Variables + +This section describes the externally-visible variables exported by +the GNU History Library. + +.Vb int history_base +The logical offset of the first entry in the history list. + +.Vb int history_length +The number of entries currently stored in the history list. + +.Vb int history_max_entries +The maximum number of history entries. This must be changed using +\fBstifle_history()\fP. + +.Vb char history_expansion_char +The character that introduces a history event. The default is \fB!\fP. +Setting this to 0 inhibits history expansion. + +.Vb char history_subst_char +The character that invokes word substitution if found at the start of +a line. The default is \fB^\fP. + +.Vb char history_comment_char +During tokenization, if this character is seen as the first character +of a word, then it and all subsequent characters up to a newline are +ignored, suppressing history expansion for the remainder of the line. +This is disabled by default. + +.Vb "char *" history_word_delimiters +The characters that separate tokens for \fBhistory_tokenize()\fP. +The default value is \fB"\ \et\en()<>;&|"\fP. + +.Vb "char *" history_no_expand_chars +The list of characters which inhibit history expansion if found immediately +following \fBhistory_expansion_char\fP. The default is space, tab, newline, +\fB\er\fP, and \fB=\fP. + +.Vb "char *" history_search_delimiter_chars +The list of additional characters which can delimit a history search +string, in addition to space, tab, \fI:\fP and \fI?\fP in the case of +a substring search. The default is empty. + +.Vb int history_quotes_inhibit_expansion +If non-zero, single-quoted words are not scanned for the history expansion +character. The default value is 0. + +.Vb "rl_linebuf_func_t *" history_inhibit_expansion_function +This should be set to the address of a function that takes two arguments: +a \fBchar *\fP (\fIstring\fP) +and an \fBint\fP index into that string (\fIi\fP). +It should return a non-zero value if the history expansion starting at +\fIstring[i]\fP should not be performed; zero if the expansion should +be done. +It is intended for use by applications like \fBbash\fP that use the history +expansion character for additional purposes. +By default, this variable is set to \fBNULL\fP. +.SH FILES +.PD 0 +.TP +.FN ~/.history +Default filename for reading and writing saved history +.PD +.SH "SEE ALSO" +.PD 0 +.TP +\fIThe Gnu Readline Library\fP, Brian Fox and Chet Ramey +.TP +\fIThe Gnu History Library\fP, Brian Fox and Chet Ramey +.TP +\fIbash\fP(1) +.TP +\fIreadline\fP(3) +.PD +.SH AUTHORS +Brian Fox, Free Software Foundation +.br +bfox@gnu.org +.PP +Chet Ramey, Case Western Reserve University +.br +chet@ins.CWRU.Edu +.SH BUG REPORTS +If you find a bug in the +.B history +library, you should report it. But first, you should +make sure that it really is a bug, and that it appears in the latest +version of the +.B history +library that you have. +.PP +Once you have determined that a bug actually exists, mail a +bug report to \fIbug\-readline\fP@\fIgnu.org\fP. +If you have a fix, you are welcome to mail that +as well! Suggestions and `philosophical' bug reports may be mailed +to \fPbug-readline\fP@\fIgnu.org\fP or posted to the Usenet +newsgroup +.BR gnu.bash.bug . +.PP +Comments and bug reports concerning +this manual page should be directed to +.IR chet@ins.CWRU.Edu . diff --git a/readline-4.2/doc/hstech.texinfo b/readline-4.2/doc/hstech.texinfo new file mode 100644 index 0000000..e4ac50c --- /dev/null +++ b/readline-4.2/doc/hstech.texinfo @@ -0,0 +1,549 @@ +@ignore +This file documents the user interface to the GNU History library. + +Copyright (C) 1988-2001 Free Software Foundation, Inc. +Authored by Brian Fox and Chet Ramey. + +Permission is granted to make and distribute verbatim copies of this manual +provided the copyright notice and this permission notice are preserved on +all copies. + +Permission is granted to process this file through Tex and print the +results, provided the printed document carries copying permission notice +identical to this one except for the removal of this paragraph (this +paragraph not being relevant to the printed manual). + +Permission is granted to copy and distribute modified versions of this +manual under the conditions for verbatim copying, provided also that the +GNU Copyright statement is available to the distributee, and provided that +the entire resulting derived work is distributed under the terms of a +permission notice identical to this one. + +Permission is granted to copy and distribute translations of this manual +into another language, under the above conditions for modified versions. +@end ignore + +@node Programming with GNU History +@chapter Programming with GNU History + +This chapter describes how to interface programs that you write +with the @sc{gnu} History Library. +It should be considered a technical guide. +For information on the interactive use of @sc{gnu} History, @pxref{Using +History Interactively}. + +@menu +* Introduction to History:: What is the GNU History library for? +* History Storage:: How information is stored. +* History Functions:: Functions that you can use. +* History Variables:: Variables that control behaviour. +* History Programming Example:: Example of using the GNU History Library. +@end menu + +@node Introduction to History +@section Introduction to History + +Many programs read input from the user a line at a time. The @sc{gnu} +History library is able to keep track of those lines, associate arbitrary +data with each line, and utilize information from previous lines in +composing new ones. + +The programmer using the History library has available functions +for remembering lines on a history list, associating arbitrary data +with a line, removing lines from the list, searching through the list +for a line containing an arbitrary text string, and referencing any line +in the list directly. In addition, a history @dfn{expansion} function +is available which provides for a consistent user interface across +different programs. + +The user using programs written with the History library has the +benefit of a consistent user interface with a set of well-known +commands for manipulating the text of previous lines and using that text +in new commands. The basic history manipulation commands are similar to +the history substitution provided by @code{csh}. + +If the programmer desires, he can use the Readline library, which +includes some history manipulation by default, and has the added +advantage of command line editing. + +Before declaring any functions using any functionality the History +library provides in other code, an application writer should include +the file @code{} in any file that uses the +History library's features. It supplies extern declarations for all +of the library's public functions and variables, and declares all of +the public data structures. + +@node History Storage +@section History Storage + +The history list is an array of history entries. A history entry is +declared as follows: + +@example +typedef void *histdata_t; + +typedef struct _hist_entry @{ + char *line; + histdata_t data; +@} HIST_ENTRY; +@end example + +The history list itself might therefore be declared as + +@example +HIST_ENTRY **the_history_list; +@end example + +The state of the History library is encapsulated into a single structure: + +@example +/* + * A structure used to pass around the current state of the history. + */ +typedef struct _hist_state @{ + HIST_ENTRY **entries; /* Pointer to the entries themselves. */ + int offset; /* The location pointer within this array. */ + int length; /* Number of elements within this array. */ + int size; /* Number of slots allocated to this array. */ + int flags; +@} HISTORY_STATE; +@end example + +If the flags member includes @code{HS_STIFLED}, the history has been +stifled. + +@node History Functions +@section History Functions + +This section describes the calling sequence for the various functions +exported by the @sc{gnu} History library. + +@menu +* Initializing History and State Management:: Functions to call when you + want to use history in a + program. +* History List Management:: Functions used to manage the list + of history entries. +* Information About the History List:: Functions returning information about + the history list. +* Moving Around the History List:: Functions used to change the position + in the history list. +* Searching the History List:: Functions to search the history list + for entries containing a string. +* Managing the History File:: Functions that read and write a file + containing the history list. +* History Expansion:: Functions to perform csh-like history + expansion. +@end menu + +@node Initializing History and State Management +@subsection Initializing History and State Management + +This section describes functions used to initialize and manage +the state of the History library when you want to use the history +functions in your program. + +@deftypefun void using_history (void) +Begin a session in which the history functions might be used. This +initializes the interactive variables. +@end deftypefun + +@deftypefun {HISTORY_STATE *} history_get_history_state (void) +Return a structure describing the current state of the input history. +@end deftypefun + +@deftypefun void history_set_history_state (HISTORY_STATE *state) +Set the state of the history list according to @var{state}. +@end deftypefun + +@node History List Management +@subsection History List Management + +These functions manage individual entries on the history list, or set +parameters managing the list itself. + +@deftypefun void add_history (const char *string) +Place @var{string} at the end of the history list. The associated data +field (if any) is set to @code{NULL}. +@end deftypefun + +@deftypefun {HIST_ENTRY *} remove_history (int which) +Remove history entry at offset @var{which} from the history. The +removed element is returned so you can free the line, data, +and containing structure. +@end deftypefun + +@deftypefun {HIST_ENTRY *} replace_history_entry (int which, const char *line, histdata_t data) +Make the history entry at offset @var{which} have @var{line} and @var{data}. +This returns the old entry so you can dispose of the data. In the case +of an invalid @var{which}, a @code{NULL} pointer is returned. +@end deftypefun + +@deftypefun void clear_history (void) +Clear the history list by deleting all the entries. +@end deftypefun + +@deftypefun void stifle_history (int max) +Stifle the history list, remembering only the last @var{max} entries. +@end deftypefun + +@deftypefun int unstifle_history (void) +Stop stifling the history. This returns the previous amount the +history was stifled. The value is positive if the history was +stifled, negative if it wasn't. +@end deftypefun + +@deftypefun int history_is_stifled (void) +Returns non-zero if the history is stifled, zero if it is not. +@end deftypefun + +@node Information About the History List +@subsection Information About the History List + +These functions return information about the entire history list or +individual list entries. + +@deftypefun {HIST_ENTRY **} history_list (void) +Return a @code{NULL} terminated array of @code{HIST_ENTRY *} which is the +current input history. Element 0 of this list is the beginning of time. +If there is no history, return @code{NULL}. +@end deftypefun + +@deftypefun int where_history (void) +Returns the offset of the current history element. +@end deftypefun + +@deftypefun {HIST_ENTRY *} current_history (void) +Return the history entry at the current position, as determined by +@code{where_history()}. If there is no entry there, return a @code{NULL} +pointer. +@end deftypefun + +@deftypefun {HIST_ENTRY *} history_get (int offset) +Return the history entry at position @var{offset}, starting from +@code{history_base} (@pxref{History Variables}). +If there is no entry there, or if @var{offset} +is greater than the history length, return a @code{NULL} pointer. +@end deftypefun + +@deftypefun int history_total_bytes (void) +Return the number of bytes that the primary history entries are using. +This function returns the sum of the lengths of all the lines in the +history. +@end deftypefun + +@node Moving Around the History List +@subsection Moving Around the History List + +These functions allow the current index into the history list to be +set or changed. + +@deftypefun int history_set_pos (int pos) +Set the current history offset to @var{pos}, an absolute index +into the list. +Returns 1 on success, 0 if @var{pos} is less than zero or greater +than the number of history entries. +@end deftypefun + +@deftypefun {HIST_ENTRY *} previous_history (void) +Back up the current history offset to the previous history entry, and +return a pointer to that entry. If there is no previous entry, return +a @code{NULL} pointer. +@end deftypefun + +@deftypefun {HIST_ENTRY *} next_history (void) +Move the current history offset forward to the next history entry, and +return the a pointer to that entry. If there is no next entry, return +a @code{NULL} pointer. +@end deftypefun + +@node Searching the History List +@subsection Searching the History List +@cindex History Searching + +These functions allow searching of the history list for entries containing +a specific string. Searching may be performed both forward and backward +from the current history position. The search may be @dfn{anchored}, +meaning that the string must match at the beginning of the history entry. +@cindex anchored search + +@deftypefun int history_search (const char *string, int direction) +Search the history for @var{string}, starting at the current history offset. +If @var{direction} is less than 0, then the search is through +previous entries, otherwise through subsequent entries. +If @var{string} is found, then +the current history index is set to that history entry, and the value +returned is the offset in the line of the entry where +@var{string} was found. Otherwise, nothing is changed, and a -1 is +returned. +@end deftypefun + +@deftypefun int history_search_prefix (const char *string, int direction) +Search the history for @var{string}, starting at the current history +offset. The search is anchored: matching lines must begin with +@var{string}. If @var{direction} is less than 0, then the search is +through previous entries, otherwise through subsequent entries. +If @var{string} is found, then the +current history index is set to that entry, and the return value is 0. +Otherwise, nothing is changed, and a -1 is returned. +@end deftypefun + +@deftypefun int history_search_pos (const char *string, int direction, int pos) +Search for @var{string} in the history list, starting at @var{pos}, an +absolute index into the list. If @var{direction} is negative, the search +proceeds backward from @var{pos}, otherwise forward. Returns the absolute +index of the history element where @var{string} was found, or -1 otherwise. +@end deftypefun + +@node Managing the History File +@subsection Managing the History File + +The History library can read the history from and write it to a file. +This section documents the functions for managing a history file. + +@deftypefun int read_history (const char *filename) +Add the contents of @var{filename} to the history list, a line at a time. +If @var{filename} is @code{NULL}, then read from @file{~/.history}. +Returns 0 if successful, or @code{errno} if not. +@end deftypefun + +@deftypefun int read_history_range (const char *filename, int from, int to) +Read a range of lines from @var{filename}, adding them to the history list. +Start reading at line @var{from} and end at @var{to}. +If @var{from} is zero, start at the beginning. If @var{to} is less than +@var{from}, then read until the end of the file. If @var{filename} is +@code{NULL}, then read from @file{~/.history}. Returns 0 if successful, +or @code{errno} if not. +@end deftypefun + +@deftypefun int write_history (const char *filename) +Write the current history to @var{filename}, overwriting @var{filename} +if necessary. +If @var{filename} is @code{NULL}, then write the history list to +@file{~/.history}. +Returns 0 on success, or @code{errno} on a read or write error. +@end deftypefun + +@deftypefun int append_history (int nelements, const char *filename) +Append the last @var{nelements} of the history list to @var{filename}. +If @var{filename} is @code{NULL}, then append to @file{~/.history}. +Returns 0 on success, or @code{errno} on a read or write error. +@end deftypefun + +@deftypefun int history_truncate_file (const char *filename, int nlines) +Truncate the history file @var{filename}, leaving only the last +@var{nlines} lines. +If @var{filename} is @code{NULL}, then @file{~/.history} is truncated. +Returns 0 on success, or @code{errno} on failure. +@end deftypefun + +@node History Expansion +@subsection History Expansion + +These functions implement history expansion. + +@deftypefun int history_expand (char *string, char **output) +Expand @var{string}, placing the result into @var{output}, a pointer +to a string (@pxref{History Interaction}). Returns: +@table @code +@item 0 +If no expansions took place (or, if the only change in +the text was the removal of escape characters preceding the history expansion +character); +@item 1 +if expansions did take place; +@item -1 +if there was an error in expansion; +@item 2 +if the returned line should be displayed, but not executed, +as with the @code{:p} modifier (@pxref{Modifiers}). +@end table + +If an error ocurred in expansion, then @var{output} contains a descriptive +error message. +@end deftypefun + +@deftypefun {char *} get_history_event (const char *string, int *cindex, int qchar) +Returns the text of the history event beginning at @var{string} + +@var{*cindex}. @var{*cindex} is modified to point to after the event +specifier. At function entry, @var{cindex} points to the index into +@var{string} where the history event specification begins. @var{qchar} +is a character that is allowed to end the event specification in addition +to the ``normal'' terminating characters. +@end deftypefun + +@deftypefun {char **} history_tokenize (const char *string) +Return an array of tokens parsed out of @var{string}, much as the +shell might. The tokens are split on the characters in the +@var{history_word_delimiters} variable, +and shell quoting conventions are obeyed. +@end deftypefun + +@deftypefun {char *} history_arg_extract (int first, int last, const char *string) +Extract a string segment consisting of the @var{first} through @var{last} +arguments present in @var{string}. Arguments are split using +@code{history_tokenize}. +@end deftypefun + +@node History Variables +@section History Variables + +This section describes the externally-visible variables exported by +the @sc{gnu} History Library. + +@deftypevar int history_base +The logical offset of the first entry in the history list. +@end deftypevar + +@deftypevar int history_length +The number of entries currently stored in the history list. +@end deftypevar + +@deftypevar int history_max_entries +The maximum number of history entries. This must be changed using +@code{stifle_history()}. +@end deftypevar + +@deftypevar char history_expansion_char +The character that introduces a history event. The default is @samp{!}. +Setting this to 0 inhibits history expansion. +@end deftypevar + +@deftypevar char history_subst_char +The character that invokes word substitution if found at the start of +a line. The default is @samp{^}. +@end deftypevar + +@deftypevar char history_comment_char +During tokenization, if this character is seen as the first character +of a word, then it and all subsequent characters up to a newline are +ignored, suppressing history expansion for the remainder of the line. +This is disabled by default. +@end deftypevar + +@deftypevar {char *} history_word_delimiters +The characters that separate tokens for \fBhistory_tokenize()\fP. +The default value is @code{" \t\n()<>;&|"}. +@end deftypevar + +@deftypevar {char *} history_no_expand_chars +The list of characters which inhibit history expansion if found immediately +following @var{history_expansion_char}. The default is space, tab, newline, +carriage return, and @samp{=}. +@end deftypevar + +@deftypevar {char *} history_search_delimiter_chars +The list of additional characters which can delimit a history search +string, in addition to space, TAB, @samp{:} and @samp{?} in the case of +a substring search. The default is empty. +@end deftypevar + +@deftypevar int history_quotes_inhibit_expansion +If non-zero, single-quoted words are not scanned for the history expansion +character. The default value is 0. +@end deftypevar + +@deftypevar {rl_linebuf_func_t *} history_inhibit_expansion_function +This should be set to the address of a function that takes two arguments: +a @code{char *} (@var{string}) +and an @code{int} index into that string (@var{i}). +It should return a non-zero value if the history expansion starting at +@var{string[i]} should not be performed; zero if the expansion should +be done. +It is intended for use by applications like Bash that use the history +expansion character for additional purposes. +By default, this variable is set to @code{NULL}. +@end deftypevar + +@node History Programming Example +@section History Programming Example + +The following program demonstrates simple use of the @sc{gnu} History Library. + +@smallexample +#include +#include + +main (argc, argv) + int argc; + char **argv; +@{ + char line[1024], *t; + int len, done = 0; + + line[0] = 0; + + using_history (); + while (!done) + @{ + printf ("history$ "); + fflush (stdout); + t = fgets (line, sizeof (line) - 1, stdin); + if (t && *t) + @{ + len = strlen (t); + if (t[len - 1] == '\n') + t[len - 1] = '\0'; + @} + + if (!t) + strcpy (line, "quit"); + + if (line[0]) + @{ + char *expansion; + int result; + + result = history_expand (line, &expansion); + if (result) + fprintf (stderr, "%s\n", expansion); + + if (result < 0 || result == 2) + @{ + free (expansion); + continue; + @} + + add_history (expansion); + strncpy (line, expansion, sizeof (line) - 1); + free (expansion); + @} + + if (strcmp (line, "quit") == 0) + done = 1; + else if (strcmp (line, "save") == 0) + write_history ("history_file"); + else if (strcmp (line, "read") == 0) + read_history ("history_file"); + else if (strcmp (line, "list") == 0) + @{ + register HIST_ENTRY **the_list; + register int i; + + the_list = history_list (); + if (the_list) + for (i = 0; the_list[i]; i++) + printf ("%d: %s\n", i + history_base, the_list[i]->line); + @} + else if (strncmp (line, "delete", 6) == 0) + @{ + int which; + if ((sscanf (line + 6, "%d", &which)) == 1) + @{ + HIST_ENTRY *entry = remove_history (which); + if (!entry) + fprintf (stderr, "No such entry %d\n", which); + else + @{ + free (entry->line); + free (entry); + @} + @} + else + @{ + fprintf (stderr, "non-numeric arg given to `delete'\n"); + @} + @} + @} +@} +@end smallexample diff --git a/readline-4.2/doc/rltech.texinfo b/readline-4.2/doc/rltech.texinfo new file mode 100644 index 0000000..acc8d4d --- /dev/null +++ b/readline-4.2/doc/rltech.texinfo @@ -0,0 +1,2083 @@ +@comment %**start of header (This is for running Texinfo on a region.) +@setfilename rltech.info +@comment %**end of header (This is for running Texinfo on a region.) +@setchapternewpage odd + +@ifinfo +This document describes the GNU Readline Library, a utility for aiding +in the consitency of user interface across discrete programs that need +to provide a command line interface. + +Copyright (C) 1988-2001 Free Software Foundation, Inc. + +Permission is granted to make and distribute verbatim copies of +this manual provided the copyright notice and this permission notice +pare preserved on all copies. + +@ignore +Permission is granted to process this file through TeX and print the +results, provided the printed document carries copying permission +notice identical to this one except for the removal of this paragraph +(this paragraph not being relevant to the printed manual). +@end ignore + +Permission is granted to copy and distribute modified versions of this +manual under the conditions for verbatim copying, provided that the entire +resulting derived work is distributed under the terms of a permission +notice identical to this one. + +Permission is granted to copy and distribute translations of this manual +into another language, under the above conditions for modified versions, +except that this permission notice may be stated in a translation approved +by the Foundation. +@end ifinfo + +@node Programming with GNU Readline +@chapter Programming with GNU Readline + +This chapter describes the interface between the @sc{gnu} Readline Library and +other programs. If you are a programmer, and you wish to include the +features found in @sc{gnu} Readline +such as completion, line editing, and interactive history manipulation +in your own programs, this section is for you. + +@menu +* Basic Behavior:: Using the default behavior of Readline. +* Custom Functions:: Adding your own functions to Readline. +* Readline Variables:: Variables accessible to custom + functions. +* Readline Convenience Functions:: Functions which Readline supplies to + aid in writing your own custom + functions. +* Readline Signal Handling:: How Readline behaves when it receives signals. +* Custom Completers:: Supplanting or supplementing Readline's + completion functions. +@end menu + +@node Basic Behavior +@section Basic Behavior + +Many programs provide a command line interface, such as @code{mail}, +@code{ftp}, and @code{sh}. For such programs, the default behaviour of +Readline is sufficient. This section describes how to use Readline in +the simplest way possible, perhaps to replace calls in your code to +@code{gets()} or @code{fgets()}. + +@findex readline +@cindex readline, function + +The function @code{readline()} prints a prompt @var{prompt} +and then reads and returns a single line of text from the user. +If @var{prompt} is @code{NULL} or the empty string, no prompt is displayed. +The line @code{readline} returns is allocated with @code{malloc()}; +the caller should @code{free()} the line when it has finished with it. +The declaration for @code{readline} in ANSI C is + +@example +@code{char *readline (const char *@var{prompt});} +@end example + +@noindent +So, one might say +@example +@code{char *line = readline ("Enter a line: ");} +@end example +@noindent +in order to read a line of text from the user. +The line returned has the final newline removed, so only the +text remains. + +If @code{readline} encounters an @code{EOF} while reading the line, and the +line is empty at that point, then @code{(char *)NULL} is returned. +Otherwise, the line is ended just as if a newline had been typed. + +If you want the user to be able to get at the line later, (with +@key{C-p} for example), you must call @code{add_history()} to save the +line away in a @dfn{history} list of such lines. + +@example +@code{add_history (line)}; +@end example + +@noindent +For full details on the GNU History Library, see the associated manual. + +It is preferable to avoid saving empty lines on the history list, since +users rarely have a burning need to reuse a blank line. Here is +a function which usefully replaces the standard @code{gets()} library +function, and has the advantage of no static buffer to overflow: + +@example +/* A static variable for holding the line. */ +static char *line_read = (char *)NULL; + +/* Read a string, and return a pointer to it. Returns NULL on EOF. */ +char * +rl_gets () +@{ + /* If the buffer has already been allocated, return the memory + to the free pool. */ + if (line_read) + @{ + free (line_read); + line_read = (char *)NULL; + @} + + /* Get a line from the user. */ + line_read = readline (""); + + /* If the line has any text in it, save it on the history. */ + if (line_read && *line_read) + add_history (line_read); + + return (line_read); +@} +@end example + +This function gives the user the default behaviour of @key{TAB} +completion: completion on file names. If you do not want Readline to +complete on filenames, you can change the binding of the @key{TAB} key +with @code{rl_bind_key()}. + +@example +@code{int rl_bind_key (int @var{key}, rl_command_func_t *@var{function});} +@end example + +@code{rl_bind_key()} takes two arguments: @var{key} is the character that +you want to bind, and @var{function} is the address of the function to +call when @var{key} is pressed. Binding @key{TAB} to @code{rl_insert()} +makes @key{TAB} insert itself. +@code{rl_bind_key()} returns non-zero if @var{key} is not a valid +ASCII character code (between 0 and 255). + +Thus, to disable the default @key{TAB} behavior, the following suffices: +@example +@code{rl_bind_key ('\t', rl_insert);} +@end example + +This code should be executed once at the start of your program; you +might write a function called @code{initialize_readline()} which +performs this and other desired initializations, such as installing +custom completers (@pxref{Custom Completers}). + +@node Custom Functions +@section Custom Functions + +Readline provides many functions for manipulating the text of +the line, but it isn't possible to anticipate the needs of all +programs. This section describes the various functions and variables +defined within the Readline library which allow a user program to add +customized functionality to Readline. + +Before declaring any functions that customize Readline's behavior, or +using any functionality Readline provides in other code, an +application writer should include the file @code{} +in any file that uses Readline's features. Since some of the definitions +in @code{readline.h} use the @code{stdio} library, the file +@code{} should be included before @code{readline.h}. + +@menu +* Readline Typedefs:: C declarations to make code readable. +* Function Writing:: Variables and calling conventions. +@end menu + +@node Readline Typedefs +@subsection Readline Typedefs + +For readabilty, we declare a number of new object types, all pointers +to functions. + +The reason for declaring these new types is to make it easier to write +code describing pointers to C functions with appropriately prototyped +arguments and return values. + +For instance, say we want to declare a variable @var{func} as a pointer +to a function which takes two @code{int} arguments and returns an +@code{int} (this is the type of all of the Readline bindable functions). +Instead of the classic C declaration + +@code{int (*func)();} + +@noindent +or the ANSI-C style declaration + +@code{int (*func)(int, int);} + +@noindent +we may write + +@code{rl_command_func_t *func;} + +The full list of function pointer types available is + +@table @code +@item typedef int rl_command_func_t (int, int); + +@item typedef char *rl_compentry_func_t (const char *, int); + +@item typedef char **rl_completion_func_t (const char *, int, int); + +@item typedef char *rl_quote_func_t (char *, int, char *); + +@item typedef char *rl_dequote_func_t (char *, int); + +@item typedef int rl_compignore_func_t (char **); + +@item typedef void rl_compdisp_func_t (char **, int, int); + +@item typedef int rl_hook_func_t (void); + +@item typedef int rl_getc_func_t (FILE *); + +@item typedef int rl_linebuf_func_t (char *, int); + +@item typedef int rl_intfunc_t (int); +@item #define rl_ivoidfunc_t rl_hook_func_t +@item typedef int rl_icpfunc_t (char *); +@item typedef int rl_icppfunc_t (char **); + +@item typedef void rl_voidfunc_t (void); +@item typedef void rl_vintfunc_t (int); +@item typedef void rl_vcpfunc_t (char *); +@item typedef void rl_vcppfunc_t (char **); + +@end table + +@node Function Writing +@subsection Writing a New Function + +In order to write new functions for Readline, you need to know the +calling conventions for keyboard-invoked functions, and the names of the +variables that describe the current state of the line read so far. + +The calling sequence for a command @code{foo} looks like + +@example +@code{foo (int count, int key)} +@end example + +@noindent +where @var{count} is the numeric argument (or 1 if defaulted) and +@var{key} is the key that invoked this function. + +It is completely up to the function as to what should be done with the +numeric argument. Some functions use it as a repeat count, some +as a flag, and others to choose alternate behavior (refreshing the current +line as opposed to refreshing the screen, for example). Some choose to +ignore it. In general, if a +function uses the numeric argument as a repeat count, it should be able +to do something useful with both negative and positive arguments. +At the very least, it should be aware that it can be passed a +negative argument. + +@node Readline Variables +@section Readline Variables + +These variables are available to function writers. + +@deftypevar {char *} rl_line_buffer +This is the line gathered so far. You are welcome to modify the +contents of the line, but see @ref{Allowing Undoing}. The +function @code{rl_extend_line_buffer} is available to increase +the memory allocated to @code{rl_line_buffer}. +@end deftypevar + +@deftypevar int rl_point +The offset of the current cursor position in @code{rl_line_buffer} +(the @emph{point}). +@end deftypevar + +@deftypevar int rl_end +The number of characters present in @code{rl_line_buffer}. When +@code{rl_point} is at the end of the line, @code{rl_point} and +@code{rl_end} are equal. +@end deftypevar + +@deftypevar int rl_mark +The @var{mark} (saved position) in the current line. If set, the mark +and point define a @emph{region}. +@end deftypevar + +@deftypevar int rl_done +Setting this to a non-zero value causes Readline to return the current +line immediately. +@end deftypevar + +@deftypevar int rl_num_chars_to_read +Setting this to a positive value before calling @code{readline()} causes +Readline to return after accepting that many characters, rather +than reading up to a character bound to @code{accept-line}. +@end deftypevar + +@deftypevar int rl_pending_input +Setting this to a value makes it the next keystroke read. This is a +way to stuff a single character into the input stream. +@end deftypevar + +@deftypevar int rl_dispatching +Set to a non-zero value if a function is being called from a key binding; +zero otherwise. Application functions can test this to discover whether +they were called directly or by Readline's dispatching mechanism. +@end deftypevar + +@deftypevar int rl_erase_empty_line +Setting this to a non-zero value causes Readline to completely erase +the current line, including any prompt, any time a newline is typed as +the only character on an otherwise-empty line. The cursor is moved to +the beginning of the newly-blank line. +@end deftypevar + +@deftypevar {char *} rl_prompt +The prompt Readline uses. This is set from the argument to +@code{readline()}, and should not be assigned to directly. +The @code{rl_set_prompt()} function (@pxref{Redisplay}) may +be used to modify the prompt string after calling @code{readline()}. +@end deftypevar + +@deftypevar int rl_already_prompted +If an application wishes to display the prompt itself, rather than have +Readline do it the first time @code{readline()} is called, it should set +this variable to a non-zero value after displaying the prompt. +The prompt must also be passed as the argument to @code{readline()} so +the redisplay functions can update the display properly. +The calling application is responsible for managing the value; Readline +never sets it. +@end deftypevar + +@deftypevar {const char *} rl_library_version +The version number of this revision of the library. +@end deftypevar + +@deftypevar {int} rl_gnu_readline_p +Always set to 1, denoting that this is @sc{gnu} readline rather than some +emulation. +@end deftypevar + +@deftypevar {const char *} rl_terminal_name +The terminal type, used for initialization. If not set by the application, +Readline sets this to the value of the @env{TERM} environment variable +the first time it is called. +@end deftypevar + +@deftypevar {const char *} rl_readline_name +This variable is set to a unique name by each application using Readline. +The value allows conditional parsing of the inputrc file +(@pxref{Conditional Init Constructs}). +@end deftypevar + +@deftypevar {FILE *} rl_instream +The stdio stream from which Readline reads input. +@end deftypevar + +@deftypevar {FILE *} rl_outstream +The stdio stream to which Readline performs output. +@end deftypevar + +@deftypevar {rl_command_func_t *} rl_last_func +The address of the last command function Readline executed. May be used to +test whether or not a function is being executed twice in succession, for +example. +@end deftypevar + +@deftypevar {rl_hook_func_t *} rl_startup_hook +If non-zero, this is the address of a function to call just +before @code{readline} prints the first prompt. +@end deftypevar + +@deftypevar {rl_hook_func_t *} rl_pre_input_hook +If non-zero, this is the address of a function to call after +the first prompt has been printed and just before @code{readline} +starts reading input characters. +@end deftypevar + +@deftypevar {rl_hook_func_t *} rl_event_hook +If non-zero, this is the address of a function to call periodically +when Readline is waiting for terminal input. +By default, this will be called at most ten times a second if there +is no keyboard input. +@end deftypevar + +@deftypevar {rl_getc_func_t *} rl_getc_function +If non-zero, Readline will call indirectly through this pointer +to get a character from the input stream. By default, it is set to +@code{rl_getc}, the default Readline character input function +(@pxref{Character Input}). +@end deftypevar + +@deftypevar {rl_voidfunc_t *} rl_redisplay_function +If non-zero, Readline will call indirectly through this pointer +to update the display with the current contents of the editing buffer. +By default, it is set to @code{rl_redisplay}, the default Readline +redisplay function (@pxref{Redisplay}). +@end deftypevar + +@deftypevar {rl_vintfunc_t *} rl_prep_term_function +If non-zero, Readline will call indirectly through this pointer +to initialize the terminal. The function takes a single argument, an +@code{int} flag that says whether or not to use eight-bit characters. +By default, this is set to @code{rl_prep_terminal} +(@pxref{Terminal Management}). +@end deftypevar + +@deftypevar {rl_voidfunc_t *} rl_deprep_term_function +If non-zero, Readline will call indirectly through this pointer +to reset the terminal. This function should undo the effects of +@code{rl_prep_term_function}. +By default, this is set to @code{rl_deprep_terminal} +(@pxref{Terminal Management}). +@end deftypevar + +@deftypevar {Keymap} rl_executing_keymap +This variable is set to the keymap (@pxref{Keymaps}) in which the +currently executing readline function was found. +@end deftypevar + +@deftypevar {Keymap} rl_binding_keymap +This variable is set to the keymap (@pxref{Keymaps}) in which the +last key binding occurred. +@end deftypevar + +@deftypevar {char *} rl_executing_macro +This variable is set to the text of any currently-executing macro. +@end deftypevar + +@deftypevar {int} rl_readline_state +A variable with bit values that encapsulate the current Readline state. +A bit is set with the @code{RL_SETSTATE} macro, and unset with the +@code{RL_UNSETSTATE} macro. Use the @code{RL_ISSTATE} macro to test +whether a particular state bit is set. Current state bits include: + +@table @code +@item RL_STATE_NONE +Readline has not yet been called, nor has it begun to intialize. +@item RL_STATE_INITIALIZING +Readline is initializing its internal data structures. +@item RL_STATE_INITIALIZED +Readline has completed its initialization. +@item RL_STATE_TERMPREPPED +Readline has modified the terminal modes to do its own input and redisplay. +@item RL_STATE_READCMD +Readline is reading a command from the keyboard. +@item RL_STATE_METANEXT +Readline is reading more input after reading the meta-prefix character. +@item RL_STATE_DISPATCHING +Readline is dispatching to a command. +@item RL_STATE_MOREINPUT +Readline is reading more input while executing an editing command. +@item RL_STATE_ISEARCH +Readline is performing an incremental history search. +@item RL_STATE_NSEARCH +Readline is performing a non-incremental history search. +@item RL_STATE_SEARCH +Readline is searching backward or forward through the history for a string. +@item RL_STATE_NUMERICARG +Readline is reading a numeric argument. +@item RL_STATE_MACROINPUT +Readline is currently getting its input from a previously-defined keyboard +macro. +@item RL_STATE_MACRODEF +Readline is currently reading characters defining a keyboard macro. +@item RL_STATE_OVERWRITE +Readline is in overwrite mode. +@item RL_STATE_COMPLETING +Readline is performing word completion. +@item RL_STATE_SIGHANDLER +Readline is currently executing the readline signal handler. +@item RL_STATE_UNDOING +Readline is performing an undo. +@item RL_STATE_DONE +Readline has read a key sequence bound to @code{accept-line} +and is about to return the line to the caller. +@end table + +@end deftypevar + +@deftypevar {int} rl_explicit_arg +Set to a non-zero value if an explicit numeric argument was specified by +the user. Only valid in a bindable command function. +@end deftypevar + +@deftypevar {int} rl_numeric_arg +Set to the value of any numeric argument explicitly specified by the user +before executing the current Readline function. Only valid in a bindable +command function. +@end deftypevar + +@deftypevar {int} rl_editing_mode +Set to a value denoting Readline's current editing mode. A value of +@var{1} means Readline is currently in emacs mode; @var{0} +means that vi mode is active. +@end deftypevar + + +@node Readline Convenience Functions +@section Readline Convenience Functions + +@menu +* Function Naming:: How to give a function you write a name. +* Keymaps:: Making keymaps. +* Binding Keys:: Changing Keymaps. +* Associating Function Names and Bindings:: Translate function names to + key sequences. +* Allowing Undoing:: How to make your functions undoable. +* Redisplay:: Functions to control line display. +* Modifying Text:: Functions to modify @code{rl_line_buffer}. +* Character Input:: Functions to read keyboard input. +* Terminal Management:: Functions to manage terminal settings. +* Utility Functions:: Generally useful functions and hooks. +* Miscellaneous Functions:: Functions that don't fall into any category. +* Alternate Interface:: Using Readline in a `callback' fashion. +* A Readline Example:: An example Readline function. +@end menu + +@node Function Naming +@subsection Naming a Function + +The user can dynamically change the bindings of keys while using +Readline. This is done by representing the function with a descriptive +name. The user is able to type the descriptive name when referring to +the function. Thus, in an init file, one might find + +@example +Meta-Rubout: backward-kill-word +@end example + +This binds the keystroke @key{Meta-Rubout} to the function +@emph{descriptively} named @code{backward-kill-word}. You, as the +programmer, should bind the functions you write to descriptive names as +well. Readline provides a function for doing that: + +@deftypefun int rl_add_defun (const char *name, rl_command_func_t *function, int key) +Add @var{name} to the list of named functions. Make @var{function} be +the function that gets called. If @var{key} is not -1, then bind it to +@var{function} using @code{rl_bind_key()}. +@end deftypefun + +Using this function alone is sufficient for most applications. It is +the recommended way to add a few functions to the default functions that +Readline has built in. If you need to do something other +than adding a function to Readline, you may need to use the +underlying functions described below. + +@node Keymaps +@subsection Selecting a Keymap + +Key bindings take place on a @dfn{keymap}. The keymap is the +association between the keys that the user types and the functions that +get run. You can make your own keymaps, copy existing keymaps, and tell +Readline which keymap to use. + +@deftypefun Keymap rl_make_bare_keymap (void) +Returns a new, empty keymap. The space for the keymap is allocated with +@code{malloc()}; the caller should free it by calling +@code{rl_discard_keymap()} when done. +@end deftypefun + +@deftypefun Keymap rl_copy_keymap (Keymap map) +Return a new keymap which is a copy of @var{map}. +@end deftypefun + +@deftypefun Keymap rl_make_keymap (void) +Return a new keymap with the printing characters bound to rl_insert, +the lowercase Meta characters bound to run their equivalents, and +the Meta digits bound to produce numeric arguments. +@end deftypefun + +@deftypefun void rl_discard_keymap (Keymap keymap) +Free the storage associated with @var{keymap}. +@end deftypefun + +Readline has several internal keymaps. These functions allow you to +change which keymap is active. + +@deftypefun Keymap rl_get_keymap (void) +Returns the currently active keymap. +@end deftypefun + +@deftypefun void rl_set_keymap (Keymap keymap) +Makes @var{keymap} the currently active keymap. +@end deftypefun + +@deftypefun Keymap rl_get_keymap_by_name (const char *name) +Return the keymap matching @var{name}. @var{name} is one which would +be supplied in a @code{set keymap} inputrc line (@pxref{Readline Init File}). +@end deftypefun + +@deftypefun {char *} rl_get_keymap_name (Keymap keymap) +Return the name matching @var{keymap}. @var{name} is one which would +be supplied in a @code{set keymap} inputrc line (@pxref{Readline Init File}). +@end deftypefun + +@node Binding Keys +@subsection Binding Keys + +Key sequences are associate with functions through the keymap. +Readline has several internal keymaps: @code{emacs_standard_keymap}, +@code{emacs_meta_keymap}, @code{emacs_ctlx_keymap}, +@code{vi_movement_keymap}, and @code{vi_insertion_keymap}. +@code{emacs_standard_keymap} is the default, and the examples in +this manual assume that. + +Since @code{readline()} installs a set of default key bindings the first +time it is called, there is always the danger that a custom binding +installed before the first call to @code{readline()} will be overridden. +An alternate mechanism is to install custom key bindings in an +initialization function assigned to the @code{rl_startup_hook} variable +(@pxref{Readline Variables}). + +These functions manage key bindings. + +@deftypefun int rl_bind_key (int key, rl_command_func_t *function) +Binds @var{key} to @var{function} in the currently active keymap. +Returns non-zero in the case of an invalid @var{key}. +@end deftypefun + +@deftypefun int rl_bind_key_in_map (int key, rl_command_func_t *function, Keymap map) +Bind @var{key} to @var{function} in @var{map}. Returns non-zero in the case +of an invalid @var{key}. +@end deftypefun + +@deftypefun int rl_unbind_key (int key) +Bind @var{key} to the null function in the currently active keymap. +Returns non-zero in case of error. +@end deftypefun + +@deftypefun int rl_unbind_key_in_map (int key, Keymap map) +Bind @var{key} to the null function in @var{map}. +Returns non-zero in case of error. +@end deftypefun + +@deftypefun int rl_unbind_function_in_map (rl_command_func_t *function, Keymap map) +Unbind all keys that execute @var{function} in @var{map}. +@end deftypefun + +@deftypefun int rl_unbind_command_in_map (const char *command, Keymap map) +Unbind all keys that are bound to @var{command} in @var{map}. +@end deftypefun + +@deftypefun int rl_set_key (const char *keyseq, rl_command_func_t *function, Keymap map) +Bind the key sequence represented by the string @var{keyseq} to the function +@var{function}. This makes new keymaps as +necessary. The initial keymap in which to do bindings is @var{map}. +@end deftypefun + +@deftypefun int rl_generic_bind (int type, const char *keyseq, char *data, Keymap map) +Bind the key sequence represented by the string @var{keyseq} to the arbitrary +pointer @var{data}. @var{type} says what kind of data is pointed to by +@var{data}; this can be a function (@code{ISFUNC}), a macro +(@code{ISMACR}), or a keymap (@code{ISKMAP}). This makes new keymaps as +necessary. The initial keymap in which to do bindings is @var{map}. +@end deftypefun + +@deftypefun int rl_parse_and_bind (char *line) +Parse @var{line} as if it had been read from the @code{inputrc} file and +perform any key bindings and variable assignments found +(@pxref{Readline Init File}). +@end deftypefun + +@deftypefun int rl_read_init_file (const char *filename) +Read keybindings and variable assignments from @var{filename} +(@pxref{Readline Init File}). +@end deftypefun + +@node Associating Function Names and Bindings +@subsection Associating Function Names and Bindings + +These functions allow you to find out what keys invoke named functions +and the functions invoked by a particular key sequence. You may also +associate a new function name with an arbitrary function. + +@deftypefun {rl_command_func_t *} rl_named_function (const char *name) +Return the function with name @var{name}. +@end deftypefun + +@deftypefun {rl_command_func_t *} rl_function_of_keyseq (const char *keyseq, Keymap map, int *type) +Return the function invoked by @var{keyseq} in keymap @var{map}. +If @var{map} is @code{NULL}, the current keymap is used. If @var{type} is +not @code{NULL}, the type of the object is returned in the @code{int} variable +it points to (one of @code{ISFUNC}, @code{ISKMAP}, or @code{ISMACR}). +@end deftypefun + +@deftypefun {char **} rl_invoking_keyseqs (rl_command_func_t *function) +Return an array of strings representing the key sequences used to +invoke @var{function} in the current keymap. +@end deftypefun + +@deftypefun {char **} rl_invoking_keyseqs_in_map (rl_command_func_t *function, Keymap map) +Return an array of strings representing the key sequences used to +invoke @var{function} in the keymap @var{map}. +@end deftypefun + +@deftypefun void rl_function_dumper (int readable) +Print the readline function names and the key sequences currently +bound to them to @code{rl_outstream}. If @var{readable} is non-zero, +the list is formatted in such a way that it can be made part of an +@code{inputrc} file and re-read. +@end deftypefun + +@deftypefun void rl_list_funmap_names (void) +Print the names of all bindable Readline functions to @code{rl_outstream}. +@end deftypefun + +@deftypefun {const char **} rl_funmap_names (void) +Return a NULL terminated array of known function names. The array is +sorted. The array itself is allocated, but not the strings inside. You +should @code{free()} the array when you are done, but not the pointers. +@end deftypefun + +@deftypefun int rl_add_funmap_entry (const char *name, rl_command_func_t *function) +Add @var{name} to the list of bindable Readline command names, and make +@var{function} the function to be called when @var{name} is invoked. +@end deftypefun + +@node Allowing Undoing +@subsection Allowing Undoing + +Supporting the undo command is a painless thing, and makes your +functions much more useful. It is certainly easy to try +something if you know you can undo it. + +If your function simply inserts text once, or deletes text once, and +uses @code{rl_insert_text()} or @code{rl_delete_text()} to do it, then +undoing is already done for you automatically. + +If you do multiple insertions or multiple deletions, or any combination +of these operations, you should group them together into one operation. +This is done with @code{rl_begin_undo_group()} and +@code{rl_end_undo_group()}. + +The types of events that can be undone are: + +@example +enum undo_code @{ UNDO_DELETE, UNDO_INSERT, UNDO_BEGIN, UNDO_END @}; +@end example + +Notice that @code{UNDO_DELETE} means to insert some text, and +@code{UNDO_INSERT} means to delete some text. That is, the undo code +tells what to undo, not how to undo it. @code{UNDO_BEGIN} and +@code{UNDO_END} are tags added by @code{rl_begin_undo_group()} and +@code{rl_end_undo_group()}. + +@deftypefun int rl_begin_undo_group (void) +Begins saving undo information in a group construct. The undo +information usually comes from calls to @code{rl_insert_text()} and +@code{rl_delete_text()}, but could be the result of calls to +@code{rl_add_undo()}. +@end deftypefun + +@deftypefun int rl_end_undo_group (void) +Closes the current undo group started with @code{rl_begin_undo_group +()}. There should be one call to @code{rl_end_undo_group()} +for each call to @code{rl_begin_undo_group()}. +@end deftypefun + +@deftypefun void rl_add_undo (enum undo_code what, int start, int end, char *text) +Remember how to undo an event (according to @var{what}). The affected +text runs from @var{start} to @var{end}, and encompasses @var{text}. +@end deftypefun + +@deftypefun void rl_free_undo_list (void) +Free the existing undo list. +@end deftypefun + +@deftypefun int rl_do_undo (void) +Undo the first thing on the undo list. Returns @code{0} if there was +nothing to undo, non-zero if something was undone. +@end deftypefun + +Finally, if you neither insert nor delete text, but directly modify the +existing text (e.g., change its case), call @code{rl_modifying()} +once, just before you modify the text. You must supply the indices of +the text range that you are going to modify. + +@deftypefun int rl_modifying (int start, int end) +Tell Readline to save the text between @var{start} and @var{end} as a +single undo unit. It is assumed that you will subsequently modify +that text. +@end deftypefun + +@node Redisplay +@subsection Redisplay + +@deftypefun void rl_redisplay (void) +Change what's displayed on the screen to reflect the current contents +of @code{rl_line_buffer}. +@end deftypefun + +@deftypefun int rl_forced_update_display (void) +Force the line to be updated and redisplayed, whether or not +Readline thinks the screen display is correct. +@end deftypefun + +@deftypefun int rl_on_new_line (void) +Tell the update functions that we have moved onto a new (empty) line, +usually after ouputting a newline. +@end deftypefun + +@deftypefun int rl_on_new_line_with_prompt (void) +Tell the update functions that we have moved onto a new line, with +@var{rl_prompt} already displayed. +This could be used by applications that want to output the prompt string +themselves, but still need Readline to know the prompt string length for +redisplay. +It should be used after setting @var{rl_already_prompted}. +@end deftypefun + +@deftypefun int rl_reset_line_state (void) +Reset the display state to a clean state and redisplay the current line +starting on a new line. +@end deftypefun + +@deftypefun int rl_crlf (void) +Move the cursor to the start of the next screen line. +@end deftypefun + +@deftypefun int rl_show_char (int c) +Display character @var{c} on @code{rl_outstream}. +If Readline has not been set to display meta characters directly, this +will convert meta characters to a meta-prefixed key sequence. +This is intended for use by applications which wish to do their own +redisplay. +@end deftypefun + +@deftypefun int rl_message (const char *, @dots{}) +The arguments are a format string as would be supplied to @code{printf}, +possibly containing conversion specifications such as @samp{%d}, and +any additional arguments necessary to satisfy the conversion specifications. +The resulting string is displayed in the @dfn{echo area}. The echo area +is also used to display numeric arguments and search strings. +@end deftypefun + +@deftypefun int rl_clear_message (void) +Clear the message in the echo area. +@end deftypefun + +@deftypefun void rl_save_prompt (void) +Save the local Readline prompt display state in preparation for +displaying a new message in the message area with @code{rl_message()}. +@end deftypefun + +@deftypefun void rl_restore_prompt (void) +Restore the local Readline prompt display state saved by the most +recent call to @code{rl_save_prompt}. +@end deftypefun + +@deftypefun int rl_expand_prompt (char *prompt) +Expand any special character sequences in @var{prompt} and set up the +local Readline prompt redisplay variables. +This function is called by @code{readline()}. It may also be called to +expand the primary prompt if the @code{rl_on_new_line_with_prompt()} +function or @code{rl_already_prompted} variable is used. +It returns the number of visible characters on the last line of the +(possibly multi-line) prompt. +@end deftypefun + +@deftypefun int rl_set_prompt (const char *prompt) +Make Readline use @var{prompt} for subsequent redisplay. This calls +@code{rl_expand_prompt()} to expand the prompt and sets @code{rl_prompt} +to the result. +@end deftypefun + +@node Modifying Text +@subsection Modifying Text + +@deftypefun int rl_insert_text (const char *text) +Insert @var{text} into the line at the current cursor position. +@end deftypefun + +@deftypefun int rl_delete_text (int start, int end) +Delete the text between @var{start} and @var{end} in the current line. +@end deftypefun + +@deftypefun {char *} rl_copy_text (int start, int end) +Return a copy of the text between @var{start} and @var{end} in +the current line. +@end deftypefun + +@deftypefun int rl_kill_text (int start, int end) +Copy the text between @var{start} and @var{end} in the current line +to the kill ring, appending or prepending to the last kill if the +last command was a kill command. The text is deleted. +If @var{start} is less than @var{end}, +the text is appended, otherwise prepended. If the last command was +not a kill, a new kill ring slot is used. +@end deftypefun + +@deftypefun int rl_push_macro_input (char *macro) +Cause @var{macro} to be inserted into the line, as if it had been invoked +by a key bound to a macro. Not especially useful; use +@code{rl_insert_text()} instead. +@end deftypefun + +@node Character Input +@subsection Character Input + +@deftypefun int rl_read_key (void) +Return the next character available from Readline's current input stream. +This handles input inserted into +the input stream via @var{rl_pending_input} (@pxref{Readline Variables}) +and @code{rl_stuff_char()}, macros, and characters read from the keyboard. +While waiting for input, this function will call any function assigned to +the @code{rl_event_hook} variable. +@end deftypefun + +@deftypefun int rl_getc (FILE *stream) +Return the next character available from @var{stream}, which is assumed to +be the keyboard. +@end deftypefun + +@deftypefun int rl_stuff_char (int c) +Insert @var{c} into the Readline input stream. It will be "read" +before Readline attempts to read characters from the terminal with +@code{rl_read_key()}. +@end deftypefun + +@deftypefun int rl_execute_next (int c) +Make @var{c} be the next command to be executed when @code{rl_read_key()} +is called. This sets @var{rl_pending_input}. +@end deftypefun + +@deftypefun int rl_clear_pending_input (void) +Unset @var{rl_pending_input}, effectively negating the effect of any +previous call to @code{rl_execute_next()}. This works only if the +pending input has not already been read with @code{rl_read_key()}. +@end deftypefun + +@deftypefun int rl_set_keyboard_input_timeout (int u) +While waiting for keyboard input in @code{rl_read_key()}, Readline will +wait for @var{u} microseconds for input before calling any function +assigned to @code{rl_event_hook}. The default waiting period is +one-tenth of a second. Returns the old timeout value. +@end deftypefun + +@node Terminal Management +@subsection Terminal Management + +@deftypefun void rl_prep_terminal (int meta_flag) +Modify the terminal settings for Readline's use, so @code{readline()} +can read a single character at a time from the keyboard. +The @var{meta_flag} argument should be non-zero if Readline should +read eight-bit input. +@end deftypefun + +@deftypefun void rl_deprep_terminal (void) +Undo the effects of @code{rl_prep_terminal()}, leaving the terminal in +the state in which it was before the most recent call to +@code{rl_prep_terminal()}. +@end deftypefun + +@deftypefun void rl_tty_set_default_bindings (Keymap kmap) +Read the operating system's terminal editing characters (as would be displayed +by @code{stty}) to their Readline equivalents. The bindings are performed +in @var{kmap}. +@end deftypefun + +@deftypefun int rl_reset_terminal (const char *terminal_name) +Reinitialize Readline's idea of the terminal settings using +@var{terminal_name} as the terminal type (e.g., @code{vt100}). +If @var{terminal_name} is @code{NULL}, the value of the @code{TERM} +environment variable is used. +@end deftypefun + +@node Utility Functions +@subsection Utility Functions + +@deftypefun int rl_extend_line_buffer (int len) +Ensure that @code{rl_line_buffer} has enough space to hold @var{len} +characters, possibly reallocating it if necessary. +@end deftypefun + +@deftypefun int rl_initialize (void) +Initialize or re-initialize Readline's internal state. +It's not strictly necessary to call this; @code{readline()} calls it before +reading any input. +@end deftypefun + +@deftypefun int rl_ding (void) +Ring the terminal bell, obeying the setting of @code{bell-style}. +@end deftypefun + +@deftypefun int rl_alphabetic (int c) +Return 1 if @var{c} is an alphabetic character. +@end deftypefun + +@deftypefun void rl_display_match_list (char **matches, int len, int max) +A convenience function for displaying a list of strings in +columnar format on Readline's output stream. @code{matches} is the list +of strings, in argv format, such as a list of completion matches. +@code{len} is the number of strings in @code{matches}, and @code{max} +is the length of the longest string in @code{matches}. This function uses +the setting of @code{print-completions-horizontally} to select how the +matches are displayed (@pxref{Readline Init File Syntax}). +@end deftypefun + +The following are implemented as macros, defined in @code{chardefs.h}. +Applications should refrain from using them. + +@deftypefun int _rl_uppercase_p (int c) +Return 1 if @var{c} is an uppercase alphabetic character. +@end deftypefun + +@deftypefun int _rl_lowercase_p (int c) +Return 1 if @var{c} is a lowercase alphabetic character. +@end deftypefun + +@deftypefun int _rl_digit_p (int c) +Return 1 if @var{c} is a numeric character. +@end deftypefun + +@deftypefun int _rl_to_upper (int c) +If @var{c} is a lowercase alphabetic character, return the corresponding +uppercase character. +@end deftypefun + +@deftypefun int _rl_to_lower (int c) +If @var{c} is an uppercase alphabetic character, return the corresponding +lowercase character. +@end deftypefun + +@deftypefun int _rl_digit_value (int c) +If @var{c} is a number, return the value it represents. +@end deftypefun + +@node Miscellaneous Functions +@subsection Miscellaneous Functions + +@deftypefun int rl_macro_bind (const char *keyseq, const char *macro, Keymap map) +Bind the key sequence @var{keyseq} to invoke the macro @var{macro}. +The binding is performed in @var{map}. When @var{keyseq} is invoked, the +@var{macro} will be inserted into the line. This function is deprecated; +use @code{rl_generic_bind()} instead. +@end deftypefun + +@deftypefun void rl_macro_dumper (int readable) +Print the key sequences bound to macros and their values, using +the current keymap, to @code{rl_outstream}. +If @var{readable} is non-zero, the list is formatted in such a way +that it can be made part of an @code{inputrc} file and re-read. +@end deftypefun + +@deftypefun int rl_variable_bind (const char *variable, const char *value) +Make the Readline variable @var{variable} have @var{value}. +This behaves as if the readline command +@samp{set @var{variable} @var{value}} had been executed in an @code{inputrc} +file (@pxref{Readline Init File Syntax}). +@end deftypefun + +@deftypefun void rl_variable_dumper (int readable) +Print the readline variable names and their current values +to @code{rl_outstream}. +If @var{readable} is non-zero, the list is formatted in such a way +that it can be made part of an @code{inputrc} file and re-read. +@end deftypefun + +@deftypefun int rl_set_paren_blink_timeout (int u) +Set the time interval (in microseconds) that Readline waits when showing +a balancing character when @code{blink-matching-paren} has been enabled. +@end deftypefun + +@node Alternate Interface +@subsection Alternate Interface + +An alternate interface is available to plain @code{readline()}. Some +applications need to interleave keyboard I/O with file, device, or +window system I/O, typically by using a main loop to @code{select()} +on various file descriptors. To accomodate this need, readline can +also be invoked as a `callback' function from an event loop. There +are functions available to make this easy. + +@deftypefun void rl_callback_handler_install (const char *prompt, rl_vcpfunc_t *lhandler) +Set up the terminal for readline I/O and display the initial +expanded value of @var{prompt}. Save the value of @var{lhandler} to +use as a function to call when a complete line of input has been entered. +The function takes the text of the line as an argument. +@end deftypefun + +@deftypefun void rl_callback_read_char (void) +Whenever an application determines that keyboard input is available, it +should call @code{rl_callback_read_char()}, which will read the next +character from the current input source. If that character completes the +line, @code{rl_callback_read_char} will invoke the @var{lhandler} +function saved by @code{rl_callback_handler_install} to process the +line. @code{EOF} is indicated by calling @var{lhandler} with a +@code{NULL} line. +@end deftypefun + +@deftypefun void rl_callback_handler_remove (void) +Restore the terminal to its initial state and remove the line handler. +This may be called from within a callback as well as independently. +@end deftypefun + +@node A Readline Example +@subsection A Readline Example + +Here is a function which changes lowercase characters to their uppercase +equivalents, and uppercase characters to lowercase. If +this function was bound to @samp{M-c}, then typing @samp{M-c} would +change the case of the character under point. Typing @samp{M-1 0 M-c} +would change the case of the following 10 characters, leaving the cursor on +the last character changed. + +@example +/* Invert the case of the COUNT following characters. */ +int +invert_case_line (count, key) + int count, key; +@{ + register int start, end, i; + + start = rl_point; + + if (rl_point >= rl_end) + return (0); + + if (count < 0) + @{ + direction = -1; + count = -count; + @} + else + direction = 1; + + /* Find the end of the range to modify. */ + end = start + (count * direction); + + /* Force it to be within range. */ + if (end > rl_end) + end = rl_end; + else if (end < 0) + end = 0; + + if (start == end) + return (0); + + if (start > end) + @{ + int temp = start; + start = end; + end = temp; + @} + + /* Tell readline that we are modifying the line, so it will save + the undo information. */ + rl_modifying (start, end); + + for (i = start; i != end; i++) + @{ + if (_rl_uppercase_p (rl_line_buffer[i])) + rl_line_buffer[i] = _rl_to_lower (rl_line_buffer[i]); + else if (_rl_lowercase_p (rl_line_buffer[i])) + rl_line_buffer[i] = _rl_to_upper (rl_line_buffer[i]); + @} + /* Move point to on top of the last character changed. */ + rl_point = (direction == 1) ? end - 1 : start; + return (0); +@} +@end example + +@node Readline Signal Handling +@section Readline Signal Handling + +Signals are asynchronous events sent to a process by the Unix kernel, +sometimes on behalf of another process. They are intended to indicate +exceptional events, like a user pressing the interrupt key on his terminal, +or a network connection being broken. There is a class of signals that can +be sent to the process currently reading input from the keyboard. Since +Readline changes the terminal attributes when it is called, it needs to +perform special processing when such a signal is received in order to +restore the terminal to a sane state, or provide application writers with +functions to do so manually. + +Readline contains an internal signal handler that is installed for a +number of signals (@code{SIGINT}, @code{SIGQUIT}, @code{SIGTERM}, +@code{SIGALRM}, @code{SIGTSTP}, @code{SIGTTIN}, and @code{SIGTTOU}). +When one of these signals is received, the signal handler +will reset the terminal attributes to those that were in effect before +@code{readline()} was called, reset the signal handling to what it was +before @code{readline()} was called, and resend the signal to the calling +application. +If and when the calling application's signal handler returns, Readline +will reinitialize the terminal and continue to accept input. +When a @code{SIGINT} is received, the Readline signal handler performs +some additional work, which will cause any partially-entered line to be +aborted (see the description of @code{rl_free_line_state()} below). + +There is an additional Readline signal handler, for @code{SIGWINCH}, which +the kernel sends to a process whenever the terminal's size changes (for +example, if a user resizes an @code{xterm}). The Readline @code{SIGWINCH} +handler updates Readline's internal screen size information, and then calls +any @code{SIGWINCH} signal handler the calling application has installed. +Readline calls the application's @code{SIGWINCH} signal handler without +resetting the terminal to its original state. If the application's signal +handler does more than update its idea of the terminal size and return (for +example, a @code{longjmp} back to a main processing loop), it @emph{must} +call @code{rl_cleanup_after_signal()} (described below), to restore the +terminal state. + +Readline provides two variables that allow application writers to +control whether or not it will catch certain signals and act on them +when they are received. It is important that applications change the +values of these variables only when calling @code{readline()}, not in +a signal handler, so Readline's internal signal state is not corrupted. + +@deftypevar int rl_catch_signals +If this variable is non-zero, Readline will install signal handlers for +@code{SIGINT}, @code{SIGQUIT}, @code{SIGTERM}, @code{SIGALRM}, +@code{SIGTSTP}, @code{SIGTTIN}, and @code{SIGTTOU}. + +The default value of @code{rl_catch_signals} is 1. +@end deftypevar + +@deftypevar int rl_catch_sigwinch +If this variable is non-zero, Readline will install a signal handler for +@code{SIGWINCH}. + +The default value of @code{rl_catch_sigwinch} is 1. +@end deftypevar + +If an application does not wish to have Readline catch any signals, or +to handle signals other than those Readline catches (@code{SIGHUP}, +for example), +Readline provides convenience functions to do the necessary terminal +and internal state cleanup upon receipt of a signal. + +@deftypefun void rl_cleanup_after_signal (void) +This function will reset the state of the terminal to what it was before +@code{readline()} was called, and remove the Readline signal handlers for +all signals, depending on the values of @code{rl_catch_signals} and +@code{rl_catch_sigwinch}. +@end deftypefun + +@deftypefun void rl_free_line_state (void) +This will free any partial state associated with the current input line +(undo information, any partial history entry, any partially-entered +keyboard macro, and any partially-entered numeric argument). This +should be called before @code{rl_cleanup_after_signal()}. The +Readline signal handler for @code{SIGINT} calls this to abort the +current input line. +@end deftypefun + +@deftypefun void rl_reset_after_signal (void) +This will reinitialize the terminal and reinstall any Readline signal +handlers, depending on the values of @code{rl_catch_signals} and +@code{rl_catch_sigwinch}. +@end deftypefun + +If an application does not wish Readline to catch @code{SIGWINCH}, it may +call @code{rl_resize_terminal()} or @code{rl_set_screen_size()} to force +Readline to update its idea of the terminal size when a @code{SIGWINCH} +is received. + +@deftypefun void rl_resize_terminal (void) +Update Readline's internal screen size by reading values from the kernel. +@end deftypefun + +@deftypefun void rl_set_screen_size (int rows, int cols) +Set Readline's idea of the terminal size to @var{rows} rows and +@var{cols} columns. +@end deftypefun + +If an application does not want to install a @code{SIGWINCH} handler, but +is still interested in the screen dimensions, Readline's idea of the screen +size may be queried. + +@deftypefun void rl_get_screen_size (int *rows, int *cols) +Return Readline's idea of the terminal's size in the +variables pointed to by the arguments. +@end deftypefun + +The following functions install and remove Readline's signal handlers. + +@deftypefun int rl_set_signals (void) +Install Readline's signal handler for @code{SIGINT}, @code{SIGQUIT}, +@code{SIGTERM}, @code{SIGALRM}, @code{SIGTSTP}, @code{SIGTTIN}, +@code{SIGTTOU}, and @code{SIGWINCH}, depending on the values of +@code{rl_catch_signals} and @code{rl_catch_sigwinch}. +@end deftypefun + +@deftypefun int rl_clear_signals (void) +Remove all of the Readline signal handlers installed by +@code{rl_set_signals()}. +@end deftypefun + +@node Custom Completers +@section Custom Completers + +Typically, a program that reads commands from the user has a way of +disambiguating commands and data. If your program is one of these, then +it can provide completion for commands, data, or both. +The following sections describe how your program and Readline +cooperate to provide this service. + +@menu +* How Completing Works:: The logic used to do completion. +* Completion Functions:: Functions provided by Readline. +* Completion Variables:: Variables which control completion. +* A Short Completion Example:: An example of writing completer subroutines. +@end menu + +@node How Completing Works +@subsection How Completing Works + +In order to complete some text, the full list of possible completions +must be available. That is, it is not possible to accurately +expand a partial word without knowing all of the possible words +which make sense in that context. The Readline library provides +the user interface to completion, and two of the most common +completion functions: filename and username. For completing other types +of text, you must write your own completion function. This section +describes exactly what such functions must do, and provides an example. + +There are three major functions used to perform completion: + +@enumerate +@item +The user-interface function @code{rl_complete()}. This function is +called with the same arguments as other bindable Readline functions: +@var{count} and @var{invoking_key}. +It isolates the word to be completed and calls +@code{rl_completion_matches()} to generate a list of possible completions. +It then either lists the possible completions, inserts the possible +completions, or actually performs the +completion, depending on which behavior is desired. + +@item +The internal function @code{rl_completion_matches()} uses an +application-supplied @dfn{generator} function to generate the list of +possible matches, and then returns the array of these matches. +The caller should place the address of its generator function in +@code{rl_completion_entry_function}. + +@item +The generator function is called repeatedly from +@code{rl_completion_matches()}, returning a string each time. The +arguments to the generator function are @var{text} and @var{state}. +@var{text} is the partial word to be completed. @var{state} is zero the +first time the function is called, allowing the generator to perform +any necessary initialization, and a positive non-zero integer for +each subsequent call. The generator function returns +@code{(char *)NULL} to inform @code{rl_completion_matches()} that there are +no more possibilities left. Usually the generator function computes the +list of possible completions when @var{state} is zero, and returns them +one at a time on subsequent calls. Each string the generator function +returns as a match must be allocated with @code{malloc()}; Readline +frees the strings when it has finished with them. + +@end enumerate + +@deftypefun int rl_complete (int ignore, int invoking_key) +Complete the word at or before point. You have supplied the function +that does the initial simple matching selection algorithm (see +@code{rl_completion_matches()}). The default is to do filename completion. +@end deftypefun + +@deftypevar {rl_compentry_func_t *} rl_completion_entry_function +This is a pointer to the generator function for +@code{rl_completion_matches()}. +If the value of @code{rl_completion_entry_function} is +@code{NULL} then the default filename generator +function, @code{rl_filename_completion_function()}, is used. +@end deftypevar + +@node Completion Functions +@subsection Completion Functions + +Here is the complete list of callable completion functions present in +Readline. + +@deftypefun int rl_complete_internal (int what_to_do) +Complete the word at or before point. @var{what_to_do} says what to do +with the completion. A value of @samp{?} means list the possible +completions. @samp{TAB} means do standard completion. @samp{*} means +insert all of the possible completions. @samp{!} means to display +all of the possible completions, if there is more than one, as well as +performing partial completion. +@end deftypefun + +@deftypefun int rl_complete (int ignore, int invoking_key) +Complete the word at or before point. You have supplied the function +that does the initial simple matching selection algorithm (see +@code{rl_completion_matches()} and @code{rl_completion_entry_function}). +The default is to do filename +completion. This calls @code{rl_complete_internal()} with an +argument depending on @var{invoking_key}. +@end deftypefun + +@deftypefun int rl_possible_completions (int count, int invoking_key) +List the possible completions. See description of @code{rl_complete +()}. This calls @code{rl_complete_internal()} with an argument of +@samp{?}. +@end deftypefun + +@deftypefun int rl_insert_completions (int count, int invoking_key) +Insert the list of possible completions into the line, deleting the +partially-completed word. See description of @code{rl_complete()}. +This calls @code{rl_complete_internal()} with an argument of @samp{*}. +@end deftypefun + +@deftypefun {char **} rl_completion_matches (const char *text, rl_compentry_func_t *entry_func) +Returns an array of strings which is a list of completions for +@var{text}. If there are no completions, returns @code{NULL}. +The first entry in the returned array is the substitution for @var{text}. +The remaining entries are the possible completions. The array is +terminated with a @code{NULL} pointer. + +@var{entry_func} is a function of two args, and returns a +@code{char *}. The first argument is @var{text}. The second is a +state argument; it is zero on the first call, and non-zero on subsequent +calls. @var{entry_func} returns a @code{NULL} pointer to the caller +when there are no more matches. +@end deftypefun + +@deftypefun {char *} rl_filename_completion_function (const char *text, int state) +A generator function for filename completion in the general case. +@var{text} is a partial filename. +The Bash source is a useful reference for writing custom +completion functions (the Bash completion functions call this and other +Readline functions). +@end deftypefun + +@deftypefun {char *} rl_username_completion_function (const char *text, int state) +A completion generator for usernames. @var{text} contains a partial +username preceded by a random character (usually @samp{~}). As with all +completion generators, @var{state} is zero on the first call and non-zero +for subsequent calls. +@end deftypefun + +@node Completion Variables +@subsection Completion Variables + +@deftypevar {rl_compentry_func_t *} rl_completion_entry_function +A pointer to the generator function for @code{rl_completion_matches()}. +@code{NULL} means to use @code{rl_filename_completion_function()}, the default +filename completer. +@end deftypevar + +@deftypevar {rl_completion_func_t *} rl_attempted_completion_function +A pointer to an alternative function to create matches. +The function is called with @var{text}, @var{start}, and @var{end}. +@var{start} and @var{end} are indices in @code{rl_line_buffer} defining +the boundaries of @var{text}, which is a character string. +If this function exists and returns @code{NULL}, or if this variable is +set to @code{NULL}, then @code{rl_complete()} will call the value of +@code{rl_completion_entry_function} to generate matches, otherwise the +array of strings returned will be used. +If this function sets the @code{rl_attempted_completion_over} +variable to a non-zero value, Readline will not perform its default +completion even if this function returns no matches. +@end deftypevar + +@deftypevar {rl_quote_func_t *} rl_filename_quoting_function +A pointer to a function that will quote a filename in an +application-specific fashion. This is called if filename completion is being +attempted and one of the characters in @code{rl_filename_quote_characters} +appears in a completed filename. The function is called with +@var{text}, @var{match_type}, and @var{quote_pointer}. The @var{text} +is the filename to be quoted. The @var{match_type} is either +@code{SINGLE_MATCH}, if there is only one completion match, or +@code{MULT_MATCH}. Some functions use this to decide whether or not to +insert a closing quote character. The @var{quote_pointer} is a pointer +to any opening quote character the user typed. Some functions choose +to reset this character. +@end deftypevar + +@deftypevar {rl_dequote_func_t *} rl_filename_dequoting_function +A pointer to a function that will remove application-specific quoting +characters from a filename before completion is attempted, so those +characters do not interfere with matching the text against names in +the filesystem. It is called with @var{text}, the text of the word +to be dequoted, and @var{quote_char}, which is the quoting character +that delimits the filename (usually @samp{'} or @samp{"}). If +@var{quote_char} is zero, the filename was not in an embedded string. +@end deftypevar + +@deftypevar {rl_linebuf_func_t *} rl_char_is_quoted_p +A pointer to a function to call that determines whether or not a specific +character in the line buffer is quoted, according to whatever quoting +mechanism the program calling Readline uses. The function is called with +two arguments: @var{text}, the text of the line, and @var{index}, the +index of the character in the line. It is used to decide whether a +character found in @code{rl_completer_word_break_characters} should be +used to break words for the completer. +@end deftypevar + +@deftypevar int rl_completion_query_items +Up to this many items will be displayed in response to a +possible-completions call. After that, we ask the user if she is sure +she wants to see them all. The default value is 100. +@end deftypevar + +@deftypevar {const char *} rl_basic_word_break_characters +The basic list of characters that signal a break between words for the +completer routine. The default value of this variable is the characters +which break words for completion in Bash: +@code{" \t\n\"\\'`@@$><=;|&@{("}. +@end deftypevar + +@deftypevar {const char *} rl_basic_quote_characters +A list of quote characters which can cause a word break. +@end deftypevar + +@deftypevar {const char *} rl_completer_word_break_characters +The list of characters that signal a break between words for +@code{rl_complete_internal()}. The default list is the value of +@code{rl_basic_word_break_characters}. +@end deftypevar + +@deftypevar {const char *} rl_completer_quote_characters +A list of characters which can be used to quote a substring of the line. +Completion occurs on the entire substring, and within the substring +@code{rl_completer_word_break_characters} are treated as any other character, +unless they also appear within this list. +@end deftypevar + +@deftypevar {const char *} rl_filename_quote_characters +A list of characters that cause a filename to be quoted by the completer +when they appear in a completed filename. The default is the null string. +@end deftypevar + +@deftypevar {const char *} rl_special_prefixes +The list of characters that are word break characters, but should be +left in @var{text} when it is passed to the completion function. +Programs can use this to help determine what kind of completing to do. +For instance, Bash sets this variable to "$@@" so that it can complete +shell variables and hostnames. +@end deftypevar + +@deftypevar {int} rl_completion_append_character +When a single completion alternative matches at the end of the command +line, this character is appended to the inserted completion text. The +default is a space character (@samp{ }). Setting this to the null +character (@samp{\0}) prevents anything being appended automatically. +This can be changed in custom completion functions to +provide the ``most sensible word separator character'' according to +an application-specific command line syntax specification. +@end deftypevar + +@deftypevar int rl_ignore_completion_duplicates +If non-zero, then duplicates in the matches are removed. +The default is 1. +@end deftypevar + +@deftypevar int rl_filename_completion_desired +Non-zero means that the results of the matches are to be treated as +filenames. This is @emph{always} zero on entry, and can only be changed +within a completion entry generator function. If it is set to a non-zero +value, directory names have a slash appended and Readline attempts to +quote completed filenames if they contain any characters in +@code{rl_filename_quote_characters} and @code{rl_filename_quoting_desired} +is set to a non-zero value. +@end deftypevar + +@deftypevar int rl_filename_quoting_desired +Non-zero means that the results of the matches are to be quoted using +double quotes (or an application-specific quoting mechanism) if the +completed filename contains any characters in +@code{rl_filename_quote_chars}. This is @emph{always} non-zero +on entry, and can only be changed within a completion entry generator +function. The quoting is effected via a call to the function pointed to +by @code{rl_filename_quoting_function}. +@end deftypevar + +@deftypevar int rl_attempted_completion_over +If an application-specific completion function assigned to +@code{rl_attempted_completion_function} sets this variable to a non-zero +value, Readline will not perform its default filename completion even +if the application's completion function returns no matches. +It should be set only by an application's completion function. +@end deftypevar + +@deftypevar int rl_completion_type +Set to a character describing the type of completion Readline is currently +attempting; see the description of @code{rl_complete_internal()} +(@pxref{Completion Functions}) for the list of characters. +@end deftypevar + +@deftypevar int rl_inhibit_completion +If this variable is non-zero, completion is inhibited. The completion +character will be inserted as any other bound to @code{self-insert}. +@end deftypevar + +@deftypevar {rl_compignore_func_t *} rl_ignore_some_completions_function +This function, if defined, is called by the completer when real filename +completion is done, after all the matching names have been generated. +It is passed a @code{NULL} terminated array of matches. +The first element (@code{matches[0]}) is the +maximal substring common to all matches. This function can +re-arrange the list of matches as required, but each element deleted +from the array must be freed. +@end deftypevar + +@deftypevar {rl_icppfunc_t *} rl_directory_completion_hook +This function, if defined, is allowed to modify the directory portion +of filenames Readline completes. It is called with the address of a +string (the current directory name) as an argument, and may modify that string. +If the string is replaced with a new string, the old value should be freed. +Any modified directory name should have a trailing slash. +The modified value will be displayed as part of the completion, replacing +the directory portion of the pathname the user typed. +It returns an integer that should be non-zero if the function modifies +its directory argument. +It could be used to expand symbolic links or shell variables in pathnames. +@end deftypevar + +@deftypevar {rl_compdisp_func_t *} rl_completion_display_matches_hook +If non-zero, then this is the address of a function to call when +completing a word would normally display the list of possible matches. +This function is called in lieu of Readline displaying the list. +It takes three arguments: +(@code{char **}@var{matches}, @code{int} @var{num_matches}, @code{int} @var{max_length}) +where @var{matches} is the array of matching strings, +@var{num_matches} is the number of strings in that array, and +@var{max_length} is the length of the longest string in that array. +Readline provides a convenience function, @code{rl_display_match_list}, +that takes care of doing the display to Readline's output stream. That +function may be called from this hook. +@end deftypevar + +@node A Short Completion Example +@subsection A Short Completion Example + +Here is a small application demonstrating the use of the GNU Readline +library. It is called @code{fileman}, and the source code resides in +@file{examples/fileman.c}. This sample application provides +completion of command names, line editing features, and access to the +history list. + +@page +@smallexample +/* fileman.c -- A tiny application which demonstrates how to use the + GNU Readline library. This application interactively allows users + to manipulate files and their modes. */ + +#include +#include +#include +#include +#include + +#include +#include + +extern char *xmalloc (); + +/* The names of functions that actually do the manipulation. */ +int com_list __P((char *)); +int com_view __P((char *)); +int com_rename __P((char *)); +int com_stat __P((char *)); +int com_pwd __P((char *)); +int com_delete __P((char *)); +int com_help __P((char *)); +int com_cd __P((char *)); +int com_quit __P((char *)); + +/* A structure which contains information on the commands this program + can understand. */ + +typedef struct @{ + char *name; /* User printable name of the function. */ + rl_icpfunc_t *func; /* Function to call to do the job. */ + char *doc; /* Documentation for this function. */ +@} COMMAND; + +COMMAND commands[] = @{ + @{ "cd", com_cd, "Change to directory DIR" @}, + @{ "delete", com_delete, "Delete FILE" @}, + @{ "help", com_help, "Display this text" @}, + @{ "?", com_help, "Synonym for `help'" @}, + @{ "list", com_list, "List files in DIR" @}, + @{ "ls", com_list, "Synonym for `list'" @}, + @{ "pwd", com_pwd, "Print the current working directory" @}, + @{ "quit", com_quit, "Quit using Fileman" @}, + @{ "rename", com_rename, "Rename FILE to NEWNAME" @}, + @{ "stat", com_stat, "Print out statistics on FILE" @}, + @{ "view", com_view, "View the contents of FILE" @}, + @{ (char *)NULL, (rl_icpfunc_t *)NULL, (char *)NULL @} +@}; + +/* Forward declarations. */ +char *stripwhite (); +COMMAND *find_command (); + +/* The name of this program, as taken from argv[0]. */ +char *progname; + +/* When non-zero, this means the user is done using this program. */ +int done; + +char * +dupstr (s) + int s; +@{ + char *r; + + r = xmalloc (strlen (s) + 1); + strcpy (r, s); + return (r); +@} + +main (argc, argv) + int argc; + char **argv; +@{ + char *line, *s; + + progname = argv[0]; + + initialize_readline (); /* Bind our completer. */ + + /* Loop reading and executing lines until the user quits. */ + for ( ; done == 0; ) + @{ + line = readline ("FileMan: "); + + if (!line) + break; + + /* Remove leading and trailing whitespace from the line. + Then, if there is anything left, add it to the history list + and execute it. */ + s = stripwhite (line); + + if (*s) + @{ + add_history (s); + execute_line (s); + @} + + free (line); + @} + exit (0); +@} + +/* Execute a command line. */ +int +execute_line (line) + char *line; +@{ + register int i; + COMMAND *command; + char *word; + + /* Isolate the command word. */ + i = 0; + while (line[i] && whitespace (line[i])) + i++; + word = line + i; + + while (line[i] && !whitespace (line[i])) + i++; + + if (line[i]) + line[i++] = '\0'; + + command = find_command (word); + + if (!command) + @{ + fprintf (stderr, "%s: No such command for FileMan.\n", word); + return (-1); + @} + + /* Get argument to command, if any. */ + while (whitespace (line[i])) + i++; + + word = line + i; + + /* Call the function. */ + return ((*(command->func)) (word)); +@} + +/* Look up NAME as the name of a command, and return a pointer to that + command. Return a NULL pointer if NAME isn't a command name. */ +COMMAND * +find_command (name) + char *name; +@{ + register int i; + + for (i = 0; commands[i].name; i++) + if (strcmp (name, commands[i].name) == 0) + return (&commands[i]); + + return ((COMMAND *)NULL); +@} + +/* Strip whitespace from the start and end of STRING. Return a pointer + into STRING. */ +char * +stripwhite (string) + char *string; +@{ + register char *s, *t; + + for (s = string; whitespace (*s); s++) + ; + + if (*s == 0) + return (s); + + t = s + strlen (s) - 1; + while (t > s && whitespace (*t)) + t--; + *++t = '\0'; + + return s; +@} + +/* **************************************************************** */ +/* */ +/* Interface to Readline Completion */ +/* */ +/* **************************************************************** */ + +char *command_generator __P((const char *, int)); +char **fileman_completion __P((const char *, int, int)); + +/* Tell the GNU Readline library how to complete. We want to try to + complete on command names if this is the first word in the line, or + on filenames if not. */ +initialize_readline () +@{ + /* Allow conditional parsing of the ~/.inputrc file. */ + rl_readline_name = "FileMan"; + + /* Tell the completer that we want a crack first. */ + rl_attempted_completion_function = fileman_completion; +@} + +/* Attempt to complete on the contents of TEXT. START and END + bound the region of rl_line_buffer that contains the word to + complete. TEXT is the word to complete. We can use the entire + contents of rl_line_buffer in case we want to do some simple + parsing. Returnthe array of matches, or NULL if there aren't any. */ +char ** +fileman_completion (text, start, end) + const char *text; + int start, end; +@{ + char **matches; + + matches = (char **)NULL; + + /* If this word is at the start of the line, then it is a command + to complete. Otherwise it is the name of a file in the current + directory. */ + if (start == 0) + matches = rl_completion_matches (text, command_generator); + + return (matches); +@} + +/* Generator function for command completion. STATE lets us + know whether to start from scratch; without any state + (i.e. STATE == 0), then we start at the top of the list. */ +char * +command_generator (text, state) + const char *text; + int state; +@{ + static int list_index, len; + char *name; + + /* If this is a new word to complete, initialize now. This + includes saving the length of TEXT for efficiency, and + initializing the index variable to 0. */ + if (!state) + @{ + list_index = 0; + len = strlen (text); + @} + + /* Return the next name which partially matches from the + command list. */ + while (name = commands[list_index].name) + @{ + list_index++; + + if (strncmp (name, text, len) == 0) + return (dupstr(name)); + @} + + /* If no names matched, then return NULL. */ + return ((char *)NULL); +@} + +/* **************************************************************** */ +/* */ +/* FileMan Commands */ +/* */ +/* **************************************************************** */ + +/* String to pass to system (). This is for the LIST, VIEW and RENAME + commands. */ +static char syscom[1024]; + +/* List the file(s) named in arg. */ +com_list (arg) + char *arg; +@{ + if (!arg) + arg = ""; + + sprintf (syscom, "ls -FClg %s", arg); + return (system (syscom)); +@} + +com_view (arg) + char *arg; +@{ + if (!valid_argument ("view", arg)) + return 1; + + sprintf (syscom, "more %s", arg); + return (system (syscom)); +@} + +com_rename (arg) + char *arg; +@{ + too_dangerous ("rename"); + return (1); +@} + +com_stat (arg) + char *arg; +@{ + struct stat finfo; + + if (!valid_argument ("stat", arg)) + return (1); + + if (stat (arg, &finfo) == -1) + @{ + perror (arg); + return (1); + @} + + printf ("Statistics for `%s':\n", arg); + + printf ("%s has %d link%s, and is %d byte%s in length.\n", arg, + finfo.st_nlink, + (finfo.st_nlink == 1) ? "" : "s", + finfo.st_size, + (finfo.st_size == 1) ? "" : "s"); + printf ("Inode Last Change at: %s", ctime (&finfo.st_ctime)); + printf (" Last access at: %s", ctime (&finfo.st_atime)); + printf (" Last modified at: %s", ctime (&finfo.st_mtime)); + return (0); +@} + +com_delete (arg) + char *arg; +@{ + too_dangerous ("delete"); + return (1); +@} + +/* Print out help for ARG, or for all of the commands if ARG is + not present. */ +com_help (arg) + char *arg; +@{ + register int i; + int printed = 0; + + for (i = 0; commands[i].name; i++) + @{ + if (!*arg || (strcmp (arg, commands[i].name) == 0)) + @{ + printf ("%s\t\t%s.\n", commands[i].name, commands[i].doc); + printed++; + @} + @} + + if (!printed) + @{ + printf ("No commands match `%s'. Possibilties are:\n", arg); + + for (i = 0; commands[i].name; i++) + @{ + /* Print in six columns. */ + if (printed == 6) + @{ + printed = 0; + printf ("\n"); + @} + + printf ("%s\t", commands[i].name); + printed++; + @} + + if (printed) + printf ("\n"); + @} + return (0); +@} + +/* Change to the directory ARG. */ +com_cd (arg) + char *arg; +@{ + if (chdir (arg) == -1) + @{ + perror (arg); + return 1; + @} + + com_pwd (""); + return (0); +@} + +/* Print out the current working directory. */ +com_pwd (ignore) + char *ignore; +@{ + char dir[1024], *s; + + s = getcwd (dir, sizeof(dir) - 1); + if (s == 0) + @{ + printf ("Error getting pwd: %s\n", dir); + return 1; + @} + + printf ("Current directory is %s\n", dir); + return 0; +@} + +/* The user wishes to quit using this program. Just set DONE + non-zero. */ +com_quit (arg) + char *arg; +@{ + done = 1; + return (0); +@} + +/* Function which tells you that you can't do this. */ +too_dangerous (caller) + char *caller; +@{ + fprintf (stderr, + "%s: Too dangerous for me to distribute. Write it yourself.\n", + caller); +@} + +/* Return non-zero if ARG is a valid argument for CALLER, else print + an error message and return zero. */ +int +valid_argument (caller, arg) + char *caller, *arg; +@{ + if (!arg || !*arg) + @{ + fprintf (stderr, "%s: Argument required.\n", caller); + return (0); + @} + + return (1); +@} +@end smallexample -- cgit v1.2.3