diplodocus.org Git - nmh/blob - docs/historical/mh-6.8.5/sbr/vfgets.c

   1 /* vfgets.c - virtual fgets */
   2 #ifndef       lint
   3 static char ident[] = "@(#)$Id: vfgets.c,v 1.3 1992/12/15 00:20:22 jromine Exp $";
   4 #endif  /*        lint */
   5
   6 #include "../h/mh.h"
   7 #include <stdio.h>
   8
   9
  10 #define QUOTE   '\\'
  11
  12
  13 int     vfgets (in, bp)
  14 register FILE *in;
  15 register char  **bp;
  16 {
  17     register int    toggle;
  18     register char  *cp,
  19                    *dp,
  20                    *ep,
  21                    *fp;
  22     static int  len = 0;
  23     static char *pp = NULL;
  24
  25     if (pp == NULL)
  26         if ((pp = malloc ((unsigned) (len = BUFSIZ))) == NULL)
  27             adios (NULLCP, "unable to allocate string storage");
  28
  29     for (ep = (cp = pp) + len - 1;;) {
  30         if (fgets (cp, ep - cp + 1, in) == NULL) {
  31             if (cp != pp) {
  32                 *bp = pp;
  33                 return OK;
  34             }
  35             return (ferror (in) && !feof (in) ? NOTOK : DONE);
  36         }
  37
  38         if ((dp = cp + strlen (cp) - 2) < cp || *dp != QUOTE) {
  39 wrong_guess: ;
  40             if (cp > ++dp)
  41                 adios (NULLCP, "vfgets() botch -- you lose big");
  42             if (*dp == '\n') {
  43                 *bp = pp;
  44                 return OK;
  45             }
  46             else
  47                 cp = ++dp;
  48         }
  49         else {
  50             for (fp = dp - 1, toggle = 0; fp >= cp; fp--)
  51                 if (*fp != QUOTE)
  52                     break;
  53                 else
  54                     toggle = !toggle;
  55             if (toggle)
  56                 goto wrong_guess;
  57             if (*++dp == '\n')
  58                 *--dp = 0, cp = dp;
  59             else
  60                 cp = ++dp;
  61         }
  62
  63         if (cp >= ep) {
  64             register int curlen = cp - pp;
  65
  66             if ((dp = realloc (pp, (unsigned) (len += BUFSIZ))) == NULL)
  67                 adios (NULLCP, "unable to allocate string storage");
  68             else
  69                 cp = dp + curlen, ep = (pp = dp) + len - 1;
  70         }
  71     }
  72 }