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
  35 #ifdef HAVE_STDLIB_H
  36 #  include <stdlib.h>
  37 #else
  38 extern void exit();
  39 #endif
  40
  41 #if defined (READLINE_LIBRARY)
  42 #  include "posixstat.h"
  43 #  include "readline.h"
  44 #  include "history.h"
  45 #else
  46 #  include <sys/stat.h>
  47 #  include <readline/readline.h>
  48 #  include <readline/history.h>
  49 #endif
  50
  51 extern int optind;
  52 extern char *optarg;
  53
  54 #if !defined (strchr) && !defined (__STDC__)
  55 extern char *strrchr();
  56 #endif
  57
  58 static char *progname;
  59 static char *deftext;
  60
  61 static int
  62 set_deftext ()
  63 {
  64   if (deftext)
  65     {
  66       rl_insert_text (deftext);
  67       deftext = (char *)NULL;
  68       rl_startup_hook = (rl_hook_func_t *)NULL;
  69     }
  70   return 0;
  71 }
  72
  73 static void
  74 usage()
  75 {
  76   fprintf (stderr, "%s: usage: %s [-p prompt] [-u unit] [-d default] [-n nchars]\n",
  77                 progname, progname);
  78 }
  79
  80 int
  81 main (argc, argv)
  82      int argc;
  83      char **argv;
  84 {
  85   char *temp, *prompt;
  86   struct stat sb;
  87   int opt, fd, nch;
  88   FILE *ifp;
  89
  90   progname = strrchr(argv[0], '/');
  91   if (progname == 0)
  92     progname = argv[0];
  93   else
  94     progname++;
  95
  96   /* defaults */
  97   prompt = "readline$ ";
  98   fd = nch = 0;
  99   deftext = (char *)0;
 100
 101   while ((opt = getopt(argc, argv, "p:u:d:n:")) != EOF)
 102     {
 103       switch (opt)
 104         {
 105         case 'p':
 106           prompt = optarg;
 107           break;
 108         case 'u':
 109           fd = atoi(optarg);
 110           if (fd < 0)
 111             {
 112               fprintf (stderr, "%s: bad file descriptor `%s'\n", progname, optarg);
 113               exit (2);
 114             }
 115           break;
 116         case 'd':
 117           deftext = optarg;
 118           break;
 119         case 'n':
 120           nch = atoi(optarg);
 121           if (nch < 0)
 122             {
 123               fprintf (stderr, "%s: bad value for -n: `%s'\n", progname, optarg);
 124               exit (2);
 125             }
 126           break;
 127         default:
 128           usage ();
 129           exit (2);
 130         }
 131     }
 132
 133   if (fd != 0)
 134     {
 135       if (fstat (fd, &sb) < 0)
 136         {
 137           fprintf (stderr, "%s: %d: bad file descriptor\n", progname, fd);
 138           exit (1);
 139         }
 140       ifp = fdopen (fd, "r");
 141       rl_instream = ifp;
 142     }
 143
 144   if (deftext && *deftext)
 145     rl_startup_hook = set_deftext;
 146
 147   if (nch > 0)
 148     rl_num_chars_to_read = nch;
 149
 150   temp = readline (prompt);
 151
 152   /* Test for EOF. */
 153   if (temp == 0)
 154     exit (1);
 155
 156   printf ("%s\n", temp);
 157   exit (0);
 158 }