src/stdio/getdelim.c

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