1 #include "stdio_impl.h"
15 unsigned char buf[UNGET+BUFSIZ], buf2[];
18 static off_t mseek(FILE *f, off_t off, int whence)
21 struct cookie *c = f->cookie;
27 base = (size_t [3]){0, c->pos, c->len}[whence];
28 if (off < -base || off > (ssize_t)c->size-base) goto fail;
29 return c->pos = base+off;
32 static size_t mread(FILE *f, unsigned char *buf, size_t len)
34 struct cookie *c = f->cookie;
35 size_t rem = c->len - c->pos;
36 if (c->pos > c->len) rem = 0;
41 memcpy(buf, c->buf+c->pos, len);
44 if (rem > f->buf_size) rem = f->buf_size;
46 f->rend = f->buf + rem;
47 memcpy(f->rpos, c->buf+c->pos, rem);
52 static size_t mwrite(FILE *f, const unsigned char *buf, size_t len)
54 struct cookie *c = f->cookie;
56 size_t len2 = f->wpos - f->wbase;
59 if (mwrite(f, f->wpos, len2) < len2) return 0;
61 if (c->mode == 'a') c->pos = c->len;
62 rem = c->size - c->pos;
63 if (len > rem) len = rem;
64 memcpy(c->buf+c->pos, buf, len);
66 if (c->pos > c->len) {
68 if (c->len < c->size) c->buf[c->len] = 0;
69 else if ((f->flags&F_NORD) && c->size) c->buf[c->size-1] = 0;
74 static int mclose(FILE *m)
79 FILE *fmemopen(void *restrict buf, size_t size, const char *restrict mode)
82 int plus = !!strchr(mode, '+');
84 if (!size || !strchr("rwa", *mode)) {
89 if (!buf && size > PTRDIFF_MAX) {
94 f = malloc(sizeof *f + (buf?0:size));
96 memset(&f->f, 0, sizeof f->f);
100 f->f.buf = f->buf + UNGET;
101 f->f.buf_size = sizeof f->buf - UNGET;
104 memset(buf, 0, size);
107 memset(&f->c, 0, sizeof f->c);
112 if (!plus) f->f.flags = (*mode == 'r') ? F_NOWR : F_NORD;
113 if (*mode == 'r') f->c.len = size;
114 else if (*mode == 'a') f->c.len = f->c.pos = strnlen(buf, size);
115 else if (plus) *f->c.buf = 0;
122 if (!libc.threaded) f->f.lock = -1;
124 return __ofl_add(&f->f);