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]
   6  */
   7
   8 /*
   9  * Remove the next line if you're compiling this against an installed
  10  * libreadline.a
  11  */
  12 #define READLINE_LIBRARY
  13
  14 #if defined (HAVE_CONFIG_H)
  15 #  include <config.h>
  16 #endif
  17
  18 #include <stdio.h>
  19 #include <sys/types.h>
  20 #include "posixstat.h"
  21 #include "readline.h"
  22 #include "history.h"
  23
  24 extern int optind;
  25 extern char *optarg;
  26
  27 #if !defined (strchr) && !defined (__STDC__)
  28 extern char *strrchr();
  29 #endif
  30
  31 static char *progname;
  32 static char *deftext;
  33
  34 static int
  35 set_deftext ()
  36 {
  37   if (deftext)
  38     {
  39       rl_insert_text (deftext);
  40       deftext = (char *)NULL;
  41       rl_startup_hook = (Function *)NULL;
  42     }
  43 }
  44
  45 static void
  46 usage()
  47 {
  48   fprintf (stderr, "%s: usage: %s [-p prompt] [-u unit] [-d default]\n",
  49                 progname, progname);
  50 }
  51
  52 main (argc, argv)
  53      int argc;
  54      char **argv;
  55 {
  56   char *temp, *prompt;
  57   struct stat sb;
  58   int opt, fd;
  59   FILE *ifp;
  60
  61   progname = strrchr(argv[0], '/');
  62   if (progname == 0)
  63     progname = argv[0];
  64   else
  65     progname++;
  66
  67   /* defaults */
  68   prompt = "readline$ ";
  69   fd = 0;
  70   deftext = (char *)0;
  71
  72   while ((opt = getopt(argc, argv, "p:u:d:")) != EOF)
  73     {
  74       switch (opt)
  75         {
  76         case 'p':
  77           prompt = optarg;
  78           break;
  79         case 'u':
  80           fd = atoi(optarg);
  81           if (fd < 0)
  82             {
  83               fprintf (stderr, "%s: bad file descriptor `%s'\n", progname, optarg);
  84               exit (2);
  85             }
  86           break;
  87         case 'd':
  88           deftext = optarg;
  89           break;
  90         default:
  91           usage ();
  92           exit (2);
  93         }
  94     }
  95
  96   if (fd != 0)
  97     {
  98       if (fstat (fd, &sb) < 0)
  99         {
 100           fprintf (stderr, "%s: %d: bad file descriptor\n", progname, fd);
 101           exit (1);
 102         }
 103       ifp = fdopen (fd, "r");
 104       rl_instream = ifp;
 105     }
 106
 107   if (deftext && *deftext)
 108     rl_startup_hook = set_deftext;
 109
 110   temp = readline (prompt);
 111
 112   /* Test for EOF. */
 113   if (temp == 0)
 114     exit (1);
 115
 116   puts (temp);
 117   exit (0);
 118 }