src/stdio/getdelim.c

   1 #include "stdio_impl.h"
   2 #include <string.h>
   3 #include <stdlib.h>
   4 #include <inttypes.h>
   5 #include <errno.h>
   6
   7 ssize_t getdelim(char **restrict s, size_t *restrict n, int delim, FILE *restrict f)
   8 {
   9         char *tmp;
  10         unsigned char *z;
  11         size_t k;
  12         size_t i=0;
  13         int c;
  14
  15         FLOCK(f);
  16
  17         if (!n || !s) {
  18                 f->mode |= f->mode-1;
  19                 f->flags |= F_ERR;
  20                 FUNLOCK(f);
  21                 errno = EINVAL;
  22                 return -1;
  23         }
  24
  25         if (!*s) *n=0;
  26
  27         for (;;) {
  28                 if (f->rpos != f->rend) {
  29                         z = memchr(f->rpos, delim, f->rend - f->rpos);
  30                         k = z ? z - f->rpos + 1 : f->rend - f->rpos;
  31                 } else {
  32                         z = 0;
  33                         k = 0;
  34                 }
  35                 if (i+k+1 >= *n) {
  36                         if (k >= SIZE_MAX/2-i) goto oom;
  37                         size_t m = i+k+2;
  38                         if (!z && m < SIZE_MAX/4) m += m/2;
  39                         tmp = realloc(*s, m);
  40                         if (!tmp) {
  41                                 m = i+k+2;
  42                                 tmp = realloc(*s, m);
  43                                 if (!tmp) goto oom;
  44                         }
  45                         *s = tmp;
  46                         *n = m;
  47                 }
  48                 memcpy(*s+i, f->rpos, k);
  49                 f->rpos += k;
  50                 i += k;
  51                 if (z) break;
  52                 if ((c = getc_unlocked(f)) == EOF) {
  53                         if (!i || !feof(f)) {
  54                                 FUNLOCK(f);
  55                                 return -1;
  56                         }
  57                         break;
  58                 }
  59                 if (((*s)[i++] = c) == delim) break;
  60         }
  61         (*s)[i] = 0;
  62
  63         FUNLOCK(f);
  64
  65         return i;
  66 oom:
  67         f->mode |= f->mode-1;
  68         f->flags |= F_ERR;
  69         FUNLOCK(f);
  70         errno = ENOMEM;
  71         return -1;
  72 }
  73
  74 weak_alias(getdelim, __getdelim);