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) 1987-2009 Free Software Foundation, Inc.
   9
  10    This file is part of the GNU Readline Library (Readline), a library for
  11    reading lines of text with interactive input and history editing.
  12
  13    Readline is free software: you can redistribute it and/or modify
  14    it under the terms of the GNU General Public License as published by
  15    the Free Software Foundation, either version 3 of the License, or
  16    (at your option) any later version.
  17
  18    Readline is distributed in the hope that it will be useful,
  19    but WITHOUT ANY WARRANTY; without even the implied warranty of
  20    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  21    GNU General Public License for more details.
  22
  23    You should have received a copy of the GNU General Public License
  24    along with Readline.  If not, see <http://www.gnu.org/licenses/>.
  25 */
  26
  27 #if defined (HAVE_CONFIG_H)
  28 #  include <config.h>
  29 #endif
  30
  31 #include <stdio.h>
  32 #include <sys/types.h>
  33
  34 #ifdef HAVE_STDLIB_H
  35 #  include <stdlib.h>
  36 #else
  37 extern void exit();
  38 #endif
  39
  40 #if defined (READLINE_LIBRARY)
  41 #  include "posixstat.h"
  42 #  include "readline.h"
  43 #  include "history.h"
  44 #else
  45 #  include <sys/stat.h>
  46 #  include <readline/readline.h>
  47 #  include <readline/history.h>
  48 #endif
  49
  50 extern int optind;
  51 extern char *optarg;
  52
  53 #if !defined (strchr) && !defined (__STDC__)
  54 extern char *strrchr();
  55 #endif
  56
  57 static char *progname;
  58 static char *deftext;
  59
  60 static int
  61 set_deftext ()
  62 {
  63   if (deftext)
  64     {
  65       rl_insert_text (deftext);
  66       deftext = (char *)NULL;
  67       rl_startup_hook = (rl_hook_func_t *)NULL;
  68     }
  69   return 0;
  70 }
  71
  72 static void
  73 usage()
  74 {
  75   fprintf (stderr, "%s: usage: %s [-p prompt] [-u unit] [-d default] [-n nchars]\n",
  76                 progname, progname);
  77 }
  78
  79 int
  80 main (argc, argv)
  81      int argc;
  82      char **argv;
  83 {
  84   char *temp, *prompt;
  85   struct stat sb;
  86   int opt, fd, nch;
  87   FILE *ifp;
  88
  89   progname = strrchr(argv[0], '/');
  90   if (progname == 0)
  91     progname = argv[0];
  92   else
  93     progname++;
  94
  95   /* defaults */
  96   prompt = "readline$ ";
  97   fd = nch = 0;
  98   deftext = (char *)0;
  99
 100   while ((opt = getopt(argc, argv, "p:u:d:n:")) != EOF)
 101     {
 102       switch (opt)
 103         {
 104         case 'p':
 105           prompt = optarg;
 106           break;
 107         case 'u':
 108           fd = atoi(optarg);
 109           if (fd < 0)
 110             {
 111               fprintf (stderr, "%s: bad file descriptor `%s'\n", progname, optarg);
 112               exit (2);
 113             }
 114           break;
 115         case 'd':
 116           deftext = optarg;
 117           break;
 118         case 'n':
 119           nch = atoi(optarg);
 120           if (nch < 0)
 121             {
 122               fprintf (stderr, "%s: bad value for -n: `%s'\n", progname, optarg);
 123               exit (2);
 124             }
 125           break;
 126         default:
 127           usage ();
 128           exit (2);
 129         }
 130     }
 131
 132   if (fd != 0)
 133     {
 134       if (fstat (fd, &sb) < 0)
 135         {
 136           fprintf (stderr, "%s: %d: bad file descriptor\n", progname, fd);
 137           exit (1);
 138         }
 139       ifp = fdopen (fd, "r");
 140       rl_instream = ifp;
 141     }
 142
 143   if (deftext && *deftext)
 144     rl_startup_hook = set_deftext;
 145
 146   if (nch > 0)
 147     rl_num_chars_to_read = nch;
 148
 149   temp = readline (prompt);
 150
 151   /* Test for EOF. */
 152   if (temp == 0)
 153     exit (1);
 154
 155   printf ("%s\n", temp);
 156   exit (0);
 157 }