source: azure_iot_hub/trunk/musl-1.1.18/src/stdio/getdelim.c@ 388

#include "stdio_impl.h"
#include <string.h>
#include <inttypes.h>
#include <errno.h>

#define MIN(a,b) ((a)<(b) ? (a) : (b))

ssize_t getdelim(char **restrict s, size_t *restrict n, int delim, FILE *restrict f)
{
        char *tmp;
        unsigned char *z;
        size_t k;
        size_t i=0;
        int c;

        FLOCK(f);

        if (!n || !s) {
                f->flags |= F_ERR;
                FUNLOCK(f);
                errno = EINVAL;
                return -1;
        }

        if (!*s) *n=0;

        for (;;) {
                z = memchr(f->rpos, delim, f->rend - f->rpos);
                k = z ? z - f->rpos + 1 : f->rend - f->rpos;
                if (i+k+1 >= *n) {
                        if (k >= SIZE_MAX/2-i) goto oom;
                        size_t m = i+k+2;
                        if (!z && m < SIZE_MAX/4) m += m/2;
                        tmp = realloc(*s, m);
                        if (!tmp) {
                                m = i+k+2;
                                tmp = realloc(*s, m);
                                if (!tmp) goto oom;
                        }
                        *s = tmp;
                        *n = m;
                }
                memcpy(*s+i, f->rpos, k);
                f->rpos += k;
                i += k;
                if (z) break;
                if ((c = getc_unlocked(f)) == EOF) {
                        if (!i || !feof(f)) {
                                FUNLOCK(f);
                                return -1;
                        }
                        break;
                }
                if (((*s)[i++] = c) == delim) break;
        }
        (*s)[i] = 0;

        FUNLOCK(f);

        return i;
oom:
        f->flags |= F_ERR;
        FUNLOCK(f);
        errno = ENOMEM;
        return -1;
}

weak_alias(getdelim, __getdelim);