usr.sbin/zic/scheck.c

   1 /*
   2  * $FreeBSD: src/usr.sbin/zic/scheck.c,v 1.4 1999/08/28 01:21:19 peter Exp $
   3  */
   4 /*LINTLIBRARY*/
   5
   6 #include "private.h"
   7
   8 const char *
   9 scheck(const char * const string, const char * const format)
  10 {
  11         char *fbuf;
  12         const char *fp;
  13         char *tp;
  14         int c;
  15         const char *result;
  16         char dummy;
  17
  18         result = "";
  19         if (string == NULL || format == NULL)
  20                 return result;
  21         fbuf = malloc(2 * strlen(format) + 4);
  22         if (fbuf == NULL)
  23                 return result;
  24         fp = format;
  25         tp = fbuf;
  26
  27         /*
  28         ** Copy directives, suppressing each conversion that is not
  29         ** already suppressed.  Scansets containing '%' are not
  30         ** supported; e.g., the conversion specification "%[%]" is not
  31         ** supported.  Also, multibyte characters containing a
  32         ** non-leading '%' byte are not supported.
  33         */
  34         while ((*tp++ = c = *fp++) != '\0') {
  35                 if (c != '%')
  36                         continue;
  37                 if (is_digit(*fp)) {
  38                         char const *f = fp;
  39                         char *t = tp;
  40                         do {
  41                                 *t++ = c = *f++;
  42                         } while (is_digit(c));
  43                         if (c == '$') {
  44                                 fp = f;
  45                                 tp = t;
  46                         }
  47                 }
  48                 *tp++ = '*';
  49                 if (*fp == '*')
  50                         ++fp;
  51                 if ((*tp++ = *fp++) == '\0')
  52                         break;
  53         }
  54
  55         *(tp - 1) = '%';
  56         *tp++ = 'c';
  57         *tp = '\0';
  58         if (sscanf(string, fbuf, &dummy) != 1)
  59                 result = format;
  60         free(fbuf);
  61         return result;
  62 }