diff options
Diffstat (limited to 'readline-4.3/examples/excallback.c')
| -rw-r--r-- | readline-4.3/examples/excallback.c | 188 |
1 files changed, 0 insertions, 188 deletions
diff --git a/readline-4.3/examples/excallback.c b/readline-4.3/examples/excallback.c deleted file mode 100644 index 3d4bb18..0000000 --- a/readline-4.3/examples/excallback.c +++ /dev/null @@ -1,188 +0,0 @@ -/* -From: Jeff Solomon <jsolomon@stanford.edu> -Date: Fri, 9 Apr 1999 10:13:27 -0700 (PDT) -To: chet@po.cwru.edu -Subject: new readline example -Message-ID: <14094.12094.527305.199695@mrclean.Stanford.EDU> - -Chet, - -I've been using readline 4.0. Specifically, I've been using the perl -version Term::ReadLine::Gnu. It works great. - -Anyway, I've been playing around the alternate interface and I wanted -to contribute a little C program, callback.c, to you that you could -use as an example of the alternate interface in the /examples -directory of the readline distribution. - -My example shows how, using the alternate interface, you can -interactively change the prompt (which is very nice imo). Also, I -point out that you must roll your own terminal setting when using the -alternate interface because readline depreps (using your parlance) the -terminal while in the user callback. I try to demostrate what I mean -with an example. I've included the program below. - -To compile, I just put the program in the examples directory and made -the appropriate changes to the EXECUTABLES and OBJECTS line and added -an additional target 'callback'. - -I compiled on my Sun Solaris2.6 box using Sun's cc. - -Let me know what you think. - -Jeff -*/ - -#if defined (HAVE_CONFIG_H) -#include <config.h> -#endif - -#include <stdio.h> -#include <sys/types.h> - -#ifdef HAVE_UNISTD_H -#include <unistd.h> -#endif - -#include <termios.h> /* xxx - should make this more general */ - -#ifdef READLINE_LIBRARY -# include "readline.h" -#else -# include <readline/readline.h> -#endif - -/* This little examples demonstrates the alternate interface to using readline. - * In the alternate interface, the user maintains control over program flow and - * only calls readline when STDIN is readable. Using the alternate interface, - * you can do anything else while still using readline (like talking to a - * network or another program) without blocking. - * - * Specifically, this program highlights two importants features of the - * alternate interface. The first is the ability to interactively change the - * prompt, which can't be done using the regular interface since rl_prompt is - * read-only. - * - * The second feature really highlights a subtle point when using the alternate - * interface. That is, readline will not alter the terminal when inside your - * callback handler. So let's so, your callback executes a user command that - * takes a non-trivial amount of time to complete (seconds). While your - * executing the command, the user continues to type keystrokes and expects them - * to be re-echoed on the new prompt when it returns. Unfortunately, the default - * terminal configuration doesn't do this. After the prompt returns, the user - * must hit one additional keystroke and then will see all of his previous - * keystrokes. To illustrate this, compile and run this program. Type "sleep" at - * the prompt and then type "bar" before the prompt returns (you have 3 - * seconds). Notice how "bar" is re-echoed on the prompt after the prompt - * returns? This is what you expect to happen. Now comment out the 4 lines below - * the line that says COMMENT LINE BELOW. Recompile and rerun the program and do - * the same thing. When the prompt returns, you should not see "bar". Now type - * "f", see how "barf" magically appears? This behavior is un-expected and not - * desired. - */ - -void process_line(char *line); -int change_prompt(void); -char *get_prompt(void); - -int prompt = 1; -char prompt_buf[40], line_buf[256]; -tcflag_t old_lflag; -cc_t old_vtime; -struct termios term; - -int -main() -{ - fd_set fds; - - /* Adjust the terminal slightly before the handler is installed. Disable - * canonical mode processing and set the input character time flag to be - * non-blocking. - */ - if( tcgetattr(STDIN_FILENO, &term) < 0 ) { - perror("tcgetattr"); - exit(1); - } - old_lflag = term.c_lflag; - old_vtime = term.c_cc[VTIME]; - term.c_lflag &= ~ICANON; - term.c_cc[VTIME] = 1; - /* COMMENT LINE BELOW - see above */ - if( tcsetattr(STDIN_FILENO, TCSANOW, &term) < 0 ) { - perror("tcsetattr"); - exit(1); - } - - rl_add_defun("change-prompt", change_prompt, CTRL('t')); - rl_callback_handler_install(get_prompt(), process_line); - - while(1) { - FD_ZERO(&fds); - FD_SET(fileno(stdin), &fds); - - if( select(FD_SETSIZE, &fds, NULL, NULL, NULL) < 0) { - perror("select"); - exit(1); - } - - if( FD_ISSET(fileno(stdin), &fds) ) { - rl_callback_read_char(); - } - } -} - -void -process_line(char *line) -{ - if( line == NULL ) { - fprintf(stderr, "\n", line); - - /* reset the old terminal setting before exiting */ - term.c_lflag = old_lflag; - term.c_cc[VTIME] = old_vtime; - if( tcsetattr(STDIN_FILENO, TCSANOW, &term) < 0 ) { - perror("tcsetattr"); - exit(1); - } - exit(0); - } - - if( strcmp(line, "sleep") == 0 ) { - sleep(3); - } else { - fprintf(stderr, "|%s|\n", line); - } - - free (line); -} - -int -change_prompt(void) -{ - /* toggle the prompt variable */ - prompt = !prompt; - - /* save away the current contents of the line */ - strcpy(line_buf, rl_line_buffer); - - /* install a new handler which will change the prompt and erase the current line */ - rl_callback_handler_install(get_prompt(), process_line); - - /* insert the old text on the new line */ - rl_insert_text(line_buf); - - /* redraw the current line - this is an undocumented function. It invokes the - * redraw-current-line command. - */ - rl_refresh_line(0, 0); -} - -char * -get_prompt(void) -{ - /* The prompts can even be different lengths! */ - sprintf(prompt_buf, "%s", - prompt ? "Hit ctrl-t to toggle prompt> " : "Pretty cool huh?> "); - return prompt_buf; -} |