readline/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 <unistd.h>
  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 }