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

   1 /* read_switch_multiword.c -- get an answer from the user and return a string array
   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 #include "ambigsw.h"
  10 #include "print_sw.h"
  11 #include "h/signals.h"
  12 #include <setjmp.h>
  13
  14 static char ansbuf[BUFSIZ];
  15 static sigjmp_buf sigenv;
  16
  17 /*
  18  * static prototypes
  19  */
  20 static void intrser (int);
  21
  22
  23 char **
  24 read_switch_multiword (const char *prompt, const struct swit *ansp)
  25 {
  26     int i;
  27     SIGNAL_HANDLER istat = NULL;
  28     char *cp, **cpp;
  29
  30     if (sigsetjmp(sigenv, 1)) {
  31         SIGNAL (SIGINT, istat);
  32         return NULL;
  33     }
  34     istat = SIGNAL (SIGINT, intrser);
  35
  36     for (;;) {
  37         fputs(prompt, stdout);
  38         fflush (stdout);
  39         cp = ansbuf;
  40         while ((i = getchar ()) != '\n') {
  41             if (i == EOF) {
  42                 /*
  43                  * If we get an EOF, return
  44                  */
  45                 if (feof(stdin))
  46                     siglongjmp (sigenv, 1);
  47
  48                 /*
  49                  * For errors, if we get an EINTR that means that we got
  50                  * a signal and we should retry.  If we get another error,
  51                  * then just return.
  52                  */
  53
  54                 if (ferror(stdin)) {
  55                     if (errno == EINTR) {
  56                         clearerr(stdin);
  57                         continue;
  58                     }
  59                     fprintf(stderr, "\nError %s during read\n",
  60                             strerror(errno));
  61                     siglongjmp (sigenv, 1);
  62                 }
  63
  64                 /* Just for completeness's sake... */
  65                 fprintf(stderr, "\nUnknown problem in getchar()\n");
  66                 siglongjmp(sigenv, 1);
  67             }
  68             if (cp < &ansbuf[sizeof ansbuf - 1])
  69                 *cp++ = i;
  70         }
  71         *cp = '\0';
  72         if (ansbuf[0] == '?' || cp == ansbuf) {
  73             puts("Options are:");
  74             print_sw (ALL, ansp, "", stdout);
  75             continue;
  76         }
  77         cpp = brkstring (ansbuf, " ", NULL);
  78         switch (smatch (*cpp, ansp)) {
  79             case AMBIGSW:
  80                 ambigsw (*cpp, ansp);
  81                 continue;
  82             case UNKWNSW:
  83                 printf (" -%s unknown. Hit <CR> for help.\n", *cpp);
  84                 continue;
  85             default:
  86                 SIGNAL (SIGINT, istat);
  87                 return cpp;
  88         }
  89     }
  90 }
  91
  92
  93 static void
  94 intrser (int i)
  95 {
  96     NMH_UNUSED (i);
  97
  98     siglongjmp (sigenv, 1);
  99 }