diplodocus.org Git - nmh/blob - sbr/read_switch.c

   1 /* read_switch.c -- prompt the user for an answer from the list
   2  *
   3  * This code is Copyright (c) 2002, by the authors of nmh.  See the
   4  * COPYRIGHT file in the root directory of the nmh distribution for
   5  * complete copyright information.
   6  */
   7
   8 #include <h/mh.h>
   9
  10
  11 int
  12 read_switch (const char *prompt, const struct swit *ansp)
  13 {
  14     int i;
  15     char *cp;
  16     const struct swit *ap;
  17     char ansbuf[BUFSIZ];
  18
  19     for (;;) {
  20         fputs(prompt, stdout);
  21         fflush (stdout);
  22         cp = ansbuf;
  23         while ((i = getchar ()) != '\n') {
  24             if (i == EOF)
  25                 return 0;
  26             if (cp < &ansbuf[sizeof ansbuf - 1]) {
  27                 i = tolower(i);
  28                 *cp++ = i;
  29             }
  30         }
  31         *cp = '\0';
  32         if (ansbuf[0] == '?' || cp == ansbuf) {
  33             puts("Options are:");
  34             for (ap = ansp; ap->sw; ap++)
  35                 printf ("  %s\n", ap->sw);
  36             continue;
  37         }
  38         if ((i = smatch (ansbuf, ansp)) < 0) {
  39             printf ("%s: %s.\n", ansbuf, i == -1 ? "unknown" : "ambiguous");
  40             continue;
  41         }
  42         return i;
  43     }
  44 }