1 #include "stdio_impl.h"
9 static off_t mseek(FILE *f, off_t off, int whence)
12 struct cookie *c = f->cookie;
18 base = (size_t [3]){0, c->pos, c->len}[whence];
19 if (off < -base || off > (ssize_t)c->size-base) goto fail;
20 return c->pos = base+off;
23 static size_t mread(FILE *f, unsigned char *buf, size_t len)
25 struct cookie *c = f->cookie;
26 size_t rem = c->len - c->pos;
27 if (c->pos > c->len) rem = 0;
32 memcpy(buf, c->buf+c->pos, len);
35 if (rem > f->buf_size) rem = f->buf_size;
37 f->rend = f->buf + rem;
38 memcpy(f->rpos, c->buf+c->pos, rem);
43 static size_t mwrite(FILE *f, const unsigned char *buf, size_t len)
45 struct cookie *c = f->cookie;
47 size_t len2 = f->wpos - f->wbase;
50 if (mwrite(f, f->wpos, len2) < len2) return 0;
52 if (c->mode == 'a') c->pos = c->len;
53 rem = c->size - c->pos;
54 if (len > rem) len = rem;
55 memcpy(c->buf+c->pos, buf, len);
57 if (c->pos >= c->len) {
59 c->buf[c->len==c->size ? c->len-1 : c->len] = 0;
64 static int mclose(FILE *m)
69 FILE *fmemopen(void *buf, size_t size, const char *mode)
73 int plus = !!strchr(mode, '+');
75 if (!size || !strchr("rwa", *mode)) {
80 if (!buf && size > SIZE_MAX-sizeof(FILE)-BUFSIZ-UNGET) {
85 f = calloc(sizeof *f + sizeof *c + UNGET + BUFSIZ + (buf?0:size), 1);
87 f->cookie = c = (void *)(f+1);
90 f->buf = (unsigned char *)(c+1) + UNGET;
92 if (!buf) buf = f->buf + BUFSIZ;
98 if (!plus) f->flags = (*mode == 'r') ? F_NOWR : F_NORD;
99 if (*mode == 'r') c->len = size;
100 else if (*mode == 'a') c->len = c->pos = strnlen(buf, size);
107 if (!libc.threaded) {
109 f->next = libc.ofl_head;
110 if (libc.ofl_head) libc.ofl_head->prev = f;