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diff --git a/readline/doc/rltech.texinfo b/readline/doc/rltech.texinfo deleted file mode 100644 index bce5087..0000000 --- a/readline/doc/rltech.texinfo +++ /dev/null @@ -1,1548 +0,0 @@ -@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, 1994, 1996 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 GNU Readline Library and -other programs. If you are a programmer, and you wish to include the -features found in 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 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 and then reads and returns -a single line of text from the user. The line @code{readline} -returns is allocated with @code{malloc ()}; you should @code{free ()} -the line when you are done with it. The declaration for @code{readline} -in ANSI C is - -@example -@code{char *readline (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}, int (*@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. - -@menu -* The Function Type:: C declarations to make code readable. -* Function Writing:: Variables and calling conventions. -@end menu - -@node The Function Type -@subsection The Function Type - -For readabilty, we declare a new type of object, called -@dfn{Function}. A @code{Function} is a C function which -returns an @code{int}. The type declaration for @code{Function} is: - -@noindent -@code{typedef int Function ();} - -The reason for declaring this new type is to make it easier to write -code describing pointers to C functions. Let us say we had a variable -called @var{func} which was a pointer to a function. Instead of the -classic C declaration - -@code{int (*)()func;} - -@noindent -we may write - -@code{Function *func;} - -@noindent -Similarly, there are - -@example -typedef void VFunction (); -typedef char *CPFunction (); @r{and} -typedef char **CPPFunction (); -@end example - -@noindent -for functions returning no value, @code{pointer to char}, and -@code{pointer to pointer to char}, respectively. - -@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}. -@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 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_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 {char *} rl_prompt -The prompt Readline uses. This is set from the argument to -@code{readline ()}, and should not be assigned to directly. -@end deftypevar - -@deftypevar {char *} rl_library_version -The version number of this revision of the library. -@end deftypevar - -@deftypevar {char *} rl_terminal_name -The terminal type, used for initialization. -@end deftypevar - -@deftypevar {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 {Function *} 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 {Function *} rl_event_hook -If non-zero, this is the address of a function to call periodically -when readline is waiting for terminal input. -@end deftypevar - -@deftypevar {Function *} rl_getc_function -If non-zero, @code{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 @code{readline} character input function -(@pxref{Utility Functions}). -@end deftypevar - -@deftypevar {VFunction *} rl_redisplay_function -If non-zero, @code{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 @code{readline} -redisplay function (@pxref{Redisplay}). -@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 - -@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}. -* Utility Functions:: Generally useful functions and hooks. -* Alternate Interface:: Using Readline in a `callback' fashion. -@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 (char *name, Function *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 () -Returns a new, empty keymap. The space for the keymap is allocated with -@code{malloc ()}; you should @code{free ()} it when you are 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 () -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 () -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 (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 - -You associate keys 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. - -These functions manage key bindings. - -@deftypefun int rl_bind_key (int key, Function *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, Function *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 (Function *function, Keymap map) -Unbind all keys that execute @var{function} in @var{map}. -@end deftypefun - -@deftypefun int rl_unbind_command_in_map (char *command, Keymap map) -Unbind all keys that are bound to @var{command} in @var{map}. -@end deftypefun - -@deftypefun int rl_generic_bind (int type, 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 (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. - -@deftypefun {Function *} rl_named_function (char *name) -Return the function with name @var{name}. -@end deftypefun - -@deftypefun {Function *} rl_function_of_keyseq (char *keyseq, Keymap map, int *type) -Return the function invoked by @var{keyseq} in keymap @var{map}. -If @var{map} is NULL, the current keymap is used. If @var{type} is -not NULL, the type of the object is returned in it (one of @code{ISFUNC}, -@code{ISKMAP}, or @code{ISMACR}). -@end deftypefun - -@deftypefun {char **} rl_invoking_keyseqs (Function *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 (Function *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 () -Print the names of all bindable Readline functions to @code{rl_outstream}. -@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. I could use an undo function for -the stock market. - -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 undo 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 () -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 () -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 free_undo_list () -Free the existing undo list. -@end deftypefun - -@deftypefun int rl_do_undo () -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 () -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 () -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 () -Tell the update routines that we have moved onto a new (empty) line, -usually after ouputting a newline. -@end deftypefun - -@deftypefun int rl_reset_line_state () -Reset the display state to a clean state and redisplay the current line -starting on a new line. -@end deftypefun - -@deftypefun int rl_message (va_alist) -The arguments are a string as would be supplied to @code{printf}. 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 () -Clear the message in the echo area. -@end deftypefun - -@node Modifying Text -@subsection Modifying Text - -@deftypefun int rl_insert_text (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 - -@node Utility Functions -@subsection Utility Functions - -@deftypefun int rl_read_key () -Return the next character available. This handles input inserted into -the input stream via @var{pending input} (@pxref{Readline Variables}) -and @code{rl_stuff_char ()}, macros, and characters read from the keyboard. -@end deftypefun - -@deftypefun int rl_getc (FILE *) -Return the next character available from 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 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 () -Initialize or re-initialize Readline's internal state. -@end deftypefun - -@deftypefun int rl_reset_terminal (char *terminal_name) -Reinitialize Readline's idea of the terminal settings using -@var{terminal_name} as the terminal type (e.g., @code{vt100}). -@end deftypefun - -@deftypefun int alphabetic (int c) -Return 1 if @var{c} is an alphabetic character. -@end deftypefun - -@deftypefun int numeric (int c) -Return 1 if @var{c} is a numeric character. -@end deftypefun - -@deftypefun int ding () -Ring the terminal bell, obeying the setting of @code{bell-style}. -@end deftypefun - -The following are implemented as macros, defined in @code{chartypes.h}. - -@deftypefun int uppercase_p (int c) -Return 1 if @var{c} is an uppercase alphabetic character. -@end deftypefun - -@deftypefun int lowercase_p (int c) -Return 1 if @var{c} is a lowercase alphabetic character. -@end deftypefun - -@deftypefun int digit_p (int c) -Return 1 if @var{c} is a numeric character. -@end deftypefun - -@deftypefun int to_upper (int c) -If @var{c} is a lowercase alphabetic character, return the corresponding -uppercase character. -@end deftypefun - -@deftypefun int to_lower (int c) -If @var{c} is an uppercase alphabetic character, return the corresponding -lowercase character. -@end deftypefun - -@deftypefun int digit_value (int c) -If @var{c} is a number, return the value it represents. -@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 (char *prompt, Vfunction *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 callback when a complete line of input has been entered. -@end deftypefun - -@deftypefun void rl_callback_read_char () -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 () -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 - -@subsection An 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 (uppercase_p (rl_line_buffer[i])) - rl_line_buffer[i] = to_lower (rl_line_buffer[i]); - else if (lowercase_p (rl_line_buffer[i])) - rl_line_buffer[i] = 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 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 Readline -functions intended for interactive use: @var{count} and -@var{invoking_key}. It isolates the word to be completed and calls -@code{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{completion_matches ()} uses your -@dfn{generator} function to generate the list of possible matches, and -then returns the array of these matches. You should place the address -of your generator function in @code{rl_completion_entry_function}. - -@item -The generator function is called repeatedly from -@code{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. When the generator function returns -@code{(char *)NULL} this signals @code{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{completion_matches ()}). The default is to do filename completion. -@end deftypefun - -@deftypevar {Function *} rl_completion_entry_function -This is a pointer to the generator function for @code{completion_matches -()}. If the value of @code{rl_completion_entry_function} is -@code{(Function *)NULL} then the default filename generator function, -@code{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{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 **} completion_matches (char *text, CPFunction *entry_func) -Returns an array of @code{(char *)} which is a list of completions for -@var{text}. If there are no completions, returns @code{(char **)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 *} filename_completion_function (char *text, int state) -A generator function for filename completion in the general case. Note -that completion in Bash is a little different because of all -the pathnames that must be followed when looking up completions for a -command. The Bash source is a useful reference for writing custom -completion functions. -@end deftypefun - -@deftypefun {char *} username_completion_function (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 {Function *} rl_completion_entry_function -A pointer to the generator function for @code{completion_matches ()}. -@code{NULL} means to use @code{filename_entry_function ()}, the default -filename completer. -@end deftypevar - -@deftypevar {CPPFunction *} 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} saying -what the boundaries of @var{text} are. 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. -@end deftypevar - -@deftypevar {CPFunction *} 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 {CPFunction *} 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 {Function *} 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 {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, i.e., -@code{" \t\n\"\\'`@@$><=;|&@{("}. -@end deftypevar - -@deftypevar {char *} rl_basic_quote_characters -List of quote characters which can cause a word break. -@end deftypevar - -@deftypevar {char *} rl_completer_word_break_characters -The list of characters that signal a break between words for -@code{rl_complete_internal ()}. The default list is the value of -@code{rl_basic_word_break_characters}. -@end deftypevar - -@deftypevar {char *} rl_completer_quote_characters -List of characters which can be used to quote a substring of the line. -Completion occurs on the entire substring, and within the substring -@code{rl_completer_word_break_characters} are treated as any other character, -unless they also appear within this list. -@end deftypevar - -@deftypevar {char *} rl_filename_quote_characters -A list of characters that cause a filename to be quoted by the completer -when they appear in a completed filename. The default is the null string. -@end deftypevar - -@deftypevar {char *} rl_special_prefixes -The list of characters that are word break characters, but should be -left in @var{text} when it is passed to the completion function. -Programs can use this to help determine what kind of completing to do. -For instance, Bash sets this variable to "$@@" 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 disallow duplicates in the matches. 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 embedded word break -characters. -@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_inhibit_completion -If this variable is non-zero, completion is inhibit<ed. The completion -character will be inserted as any other bound to @code{self-insert}. -@end deftypevar - -@deftypevar {Function *} 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 {Function *} 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. It could be used -to expand symbolic links or shell variables in pathnames. -@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 <stdio.h> -#include <sys/types.h> -#include <sys/file.h> -#include <sys/stat.h> -#include <sys/errno.h> - -#include <readline/readline.h> -#include <readline/history.h> - -extern char *getwd (); -extern char *xmalloc (); - -/* The names of functions that actually do the manipulation. */ -int com_list (), com_view (), com_rename (), com_stat (), com_pwd (); -int com_delete (), com_help (), com_cd (), com_quit (); - -/* A structure which contains information on the commands this program - can understand. */ - -typedef struct @{ - char *name; /* User printable name of the function. */ - Function *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, (Function *)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 global 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 (); -char **fileman_completion (); - -/* 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 = (CPPFunction *)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. Return the array of matches, - or NULL if there aren't any. */ -char ** -fileman_completion (text, start, end) - 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 = 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) - 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 = getwd (dir); - 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 |