src/stdio/getdelim.c

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