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         if (!n || !s) {
  17                 errno = EINVAL;
  18                 return -1;
  19         }
  20
  21         if (!*s) *n=0;
  22
  23         FLOCK(f);
  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 >= *n) {
  29                         if (k >= SIZE_MAX/2-i) goto oom;
  30                         *n = i+k+2;
  31                         if (*n < SIZE_MAX/4) *n *= 2;
  32                         tmp = realloc(*s, *n);
  33                         if (!tmp) {
  34                                 *n = i+k+2;
  35                                 tmp = realloc(*s, *n);
  36                                 if (!tmp) goto oom;
  37                         }
  38                         *s = tmp;
  39                 }
  40                 memcpy(*s+i, f->rpos, k);
  41                 f->rpos += k;
  42                 i += k;
  43                 if (z) break;
  44                 if ((c = getc_unlocked(f)) == EOF) {
  45                         if (!i || !feof(f)) {
  46                                 FUNLOCK(f);
  47                                 return -1;
  48                         }
  49                         break;
  50                 }
  51                 if (((*s)[i++] = c) == delim) break;
  52         }
  53         (*s)[i] = 0;
  54
  55         FUNLOCK(f);
  56
  57         return i;
  58 oom:
  59         FUNLOCK(f);
  60         errno = ENOMEM;
  61         return -1;
  62 }
  63
  64 weak_alias(getdelim, __getdelim);