readline/examples/rl-callbacktest.c

   1 /* Standard include files. stdio.h is required. */
   2 #include <stdlib.h>
   3 #include <unistd.h>
   4 #include <string.h>
   5
   6 /* Used for select(2) */
   7 #include <sys/types.h>
   8 #include <sys/select.h>
   9
  10 #include <errno.h>
  11 #include <stdio.h>
  12
  13 /* Standard readline include files. */
  14 #if defined (READLINE_LIBRARY)
  15 #  include "readline.h"
  16 #  include "history.h"
  17 #else
  18 #  include <readline/readline.h>
  19 #  include <readline/history.h>
  20 #endif
  21
  22 extern int errno;
  23
  24 static void cb_linehandler (char *);
  25
  26 int running;
  27 const char *prompt = "rltest$ ";
  28
  29 /* Callback function called for each line when accept-line executed, EOF
  30    seen, or EOF character read.  This sets a flag and returns; it could
  31    also call exit(3). */
  32 static void
  33 cb_linehandler (char *line)
  34 {
  35   /* Can use ^D (stty eof) or `exit' to exit. */
  36   if (line == NULL || strcmp (line, "exit") == 0)
  37     {
  38       if (line == 0)
  39         printf ("\n");
  40       printf ("exit\n");
  41       /* This function needs to be called to reset the terminal settings,
  42          and calling it from the line handler keeps one extra prompt from
  43          being displayed. */
  44       rl_callback_handler_remove ();
  45
  46       running = 0;
  47     }
  48   else
  49     {
  50       if (*line)
  51         add_history (line);
  52       printf ("input line: %s\n", line);
  53       free (line);
  54     }
  55 }
  56
  57 int
  58 main (int c, char **v)
  59 {
  60   fd_set fds;
  61   int r;
  62
  63   /* Install the line handler. */
  64   rl_callback_handler_install (prompt, cb_linehandler);
  65
  66   /* Enter a simple event loop.  This waits until something is available
  67      to read on readline's input stream (defaults to standard input) and
  68      calls the builtin character read callback to read it.  It does not
  69      have to modify the user's terminal settings. */
  70   running = 1;
  71   while (running)
  72     {
  73       FD_ZERO (&fds);
  74       FD_SET (fileno (rl_instream), &fds);
  75
  76       r = select (FD_SETSIZE, &fds, NULL, NULL, NULL);
  77       if (r < 0 && errno != EINTR)
  78         {
  79           perror ("rltest: select");
  80           rl_callback_handler_remove ();
  81           break;
  82         }
  83
  84       if (FD_ISSET (fileno (rl_instream), &fds))
  85         rl_callback_read_char ();
  86     }
  87
  88   printf ("rltest: Event loop has exited\n");
  89   return 0;
  90 }