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 <h/signals.h>
  10 #include <setjmp.h>
  11
  12 static char ansbuf[BUFSIZ];
  13 static sigjmp_buf sigenv;
  14
  15 /*
  16  * static prototypes
  17  */
  18 static void intrser (int);
  19
  20
  21 char **
  22 read_switch_multiword (const char *prompt, const struct swit *ansp)
  23 {
  24     int i;
  25     SIGNAL_HANDLER istat = NULL;
  26     char *cp, **cpp;
  27
  28     if (!(sigsetjmp(sigenv, 1))) {
  29         istat = SIGNAL (SIGINT, intrser);
  30     } else {
  31         SIGNAL (SIGINT, istat);
  32         return NULL;
  33     }
  34
  35     for (;;) {
  36         fputs(prompt, stdout);
  37         fflush (stdout);
  38         cp = ansbuf;
  39         while ((i = getchar ()) != '\n') {
  40             if (i == EOF) {
  41                 /*
  42                  * If we get an EOF, return
  43                  */
  44                 if (feof(stdin))
  45                     siglongjmp (sigenv, 1);
  46
  47                 /*
  48                  * For errors, if we get an EINTR that means that we got
  49                  * a signal and we should retry.  If we get another error,
  50                  * then just return.
  51                  */
  52
  53                 else if (ferror(stdin)) {
  54                     if (errno == EINTR) {
  55                         clearerr(stdin);
  56                         continue;
  57                     }
  58                     fprintf(stderr, "\nError %s during read\n",
  59                             strerror(errno));
  60                     siglongjmp (sigenv, 1);
  61                 } else {
  62                     /*
  63                      * Just for completeness's sake ...
  64                      */
  65
  66                     fprintf(stderr, "\nUnknown problem in getchar()\n");
  67                     siglongjmp (sigenv, 1);
  68                 }
  69             }
  70             if (cp < &ansbuf[sizeof ansbuf - 1])
  71                 *cp++ = i;
  72         }
  73         *cp = '\0';
  74         if (ansbuf[0] == '?' || cp == ansbuf) {
  75             puts("Options are:");
  76             print_sw (ALL, ansp, "", stdout);
  77             continue;
  78         }
  79         cpp = brkstring (ansbuf, " ", NULL);
  80         switch (smatch (*cpp, ansp)) {
  81             case AMBIGSW:
  82                 ambigsw (*cpp, ansp);
  83                 continue;
  84             case UNKWNSW:
  85                 printf (" -%s unknown. Hit <CR> for help.\n", *cpp);
  86                 continue;
  87             default:
  88                 SIGNAL (SIGINT, istat);
  89                 return cpp;
  90         }
  91     }
  92 }
  93
  94
  95 static void
  96 intrser (int i)
  97 {
  98     NMH_UNUSED (i);
  99
 100     /*
 101      * should this be siglongjmp?
 102      */
 103     siglongjmp (sigenv, 1);
 104 }