readline/examples/rl.c

   1 /*
   2  * rl - command-line interface to read a line from the standard input
   3  *      (or another fd) using readline.
   4  *
   5  * usage: rl [-p prompt] [-u unit] [-d default] [-n nchars]
   6  */
   7
   8 /* Copyright (C) 1987-2002 Free Software Foundation, Inc.
   9
  10    This file is part of the GNU Readline Library, a library for
  11    reading lines of text with interactive input and history editing.
  12
  13    The GNU Readline Library is free software; you can redistribute it
  14    and/or modify it under the terms of the GNU General Public License
  15    as published by the Free Software Foundation; either version 2, or
  16    (at your option) any later version.
  17
  18    The GNU Readline Library is distributed in the hope that it will be
  19    useful, but WITHOUT ANY WARRANTY; without even the implied warranty
  20    of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  21    GNU General Public License for more details.
  22
  23    The GNU General Public License is often shipped with GNU software, and
  24    is generally kept in a file called COPYING or LICENSE.  If you do not
  25    have a copy of the license, write to the Free Software Foundation,
  26    59 Temple Place, Suite 330, Boston, MA 02111 USA. */
  27
  28 #if defined (HAVE_CONFIG_H)
  29 #  include <config.h>
  30 #endif
  31
  32 #include <stdio.h>
  33 #include <sys/types.h>
  34 #include "posixstat.h"
  35
  36 #if defined (READLINE_LIBRARY)
  37 #  include "readline.h"
  38 #  include "history.h"
  39 #else
  40 #  include <readline/readline.h>
  41 #  include <readline/history.h>
  42 #endif
  43
  44 extern int optind;
  45 extern char *optarg;
  46
  47 #if !defined (strchr) && !defined (__STDC__)
  48 extern char *strrchr();
  49 #endif
  50
  51 static char *progname;
  52 static char *deftext;
  53
  54 static int
  55 set_deftext ()
  56 {
  57   if (deftext)
  58     {
  59       rl_insert_text (deftext);
  60       deftext = (char *)NULL;
  61       rl_startup_hook = (rl_hook_func_t *)NULL;
  62     }
  63   return 0;
  64 }
  65
  66 static void
  67 usage()
  68 {
  69   fprintf (stderr, "%s: usage: %s [-p prompt] [-u unit] [-d default] [-n nchars]\n",
  70                 progname, progname);
  71 }
  72
  73 int
  74 main (argc, argv)
  75      int argc;
  76      char **argv;
  77 {
  78   char *temp, *prompt;
  79   struct stat sb;
  80   int opt, fd, nch;
  81   FILE *ifp;
  82
  83   progname = strrchr(argv[0], '/');
  84   if (progname == 0)
  85     progname = argv[0];
  86   else
  87     progname++;
  88
  89   /* defaults */
  90   prompt = "readline$ ";
  91   fd = nch = 0;
  92   deftext = (char *)0;
  93
  94   while ((opt = getopt(argc, argv, "p:u:d:n:")) != EOF)
  95     {
  96       switch (opt)
  97         {
  98         case 'p':
  99           prompt = optarg;
 100           break;
 101         case 'u':
 102           fd = atoi(optarg);
 103           if (fd < 0)
 104             {
 105               fprintf (stderr, "%s: bad file descriptor `%s'\n", progname, optarg);
 106               exit (2);
 107             }
 108           break;
 109         case 'd':
 110           deftext = optarg;
 111           break;
 112         case 'n':
 113           nch = atoi(optarg);
 114           if (nch < 0)
 115             {
 116               fprintf (stderr, "%s: bad value for -n: `%s'\n", progname, optarg);
 117               exit (2);
 118             }
 119           break;
 120         default:
 121           usage ();
 122           exit (2);
 123         }
 124     }
 125
 126   if (fd != 0)
 127     {
 128       if (fstat (fd, &sb) < 0)
 129         {
 130           fprintf (stderr, "%s: %d: bad file descriptor\n", progname, fd);
 131           exit (1);
 132         }
 133       ifp = fdopen (fd, "r");
 134       rl_instream = ifp;
 135     }
 136
 137   if (deftext && *deftext)
 138     rl_startup_hook = set_deftext;
 139
 140   if (nch > 0)
 141     rl_num_chars_to_read = nch;
 142
 143   temp = readline (prompt);
 144
 145   /* Test for EOF. */
 146   if (temp == 0)
 147     exit (1);
 148
 149   printf ("%s\n", temp);
 150   exit (0);
 151 }