BSD 4_3 development

[unix-history] / usr / contrib / mh / sbr / vfgets.c

/* vfgets.c - virtual fgets */

#include "../h/mh.h"
#include <stdio.h>


#define QUOTE   '\\'


int     vfgets (in, bp)
register FILE *in;
register char  **bp;
{
   register int    toggle;
   register char  *cp,
                  *dp,
                  *ep,
                  *fp;
   static int  len = 0;
   static char *pp = NULL;

   if (pp == NULL)
       if ((pp = malloc ((unsigned) (len = BUFSIZ))) == NULL)
           adios (NULLCP, "unable to allocate string storage");

   for (ep = (cp = pp) + len - 1;;) {
       if (fgets (cp, ep - cp + 1, in) == NULL) {
           if (cp != pp) {
               *bp = pp;
               return OK;
           }
           return (ferror (in) ? NOTOK : DONE);
       }

       if ((dp = cp + strlen (cp) - 2) < cp || *dp != QUOTE) {
wrong_guess: ;
           if (cp > ++dp)
               adios (NULLCP, "vfgets() botch -- you lose big");
           if (*dp == '\n') {
               *bp = pp;
               return OK;
           }
           else
               cp = ++dp;
       }
       else {
           for (fp = dp - 1, toggle = 0; fp >= cp; fp--)
               if (*fp != QUOTE)
                   break;
               else
                   toggle = !toggle;
           if (toggle)
               goto wrong_guess;
           if (*++dp == '\n')
               *--dp = NULL, cp = dp;
           else
               cp = ++dp;
       }

       if (cp >= ep) {
           register int curlen = cp - pp;

           if ((dp = realloc (pp, (unsigned) (len += BUFSIZ))) == NULL)
               adios (NULLCP, "unable to allocate string storage");
           else
               cp = dp + curlen, ep = (pp = dp) + len - 1;
       }
   }
}