1 #include "stdio_impl.h"
17 unsigned char buf[UNGET+BUFSIZ], buf2[];
20 static off_t mseek(FILE *f, off_t off, int whence)
23 struct cookie *c = f->cookie;
29 base = (size_t [3]){0, c->pos, c->len}[whence];
30 if (off < -base || off > (ssize_t)c->size-base) goto fail;
31 return c->pos = base+off;
34 static size_t mread(FILE *f, unsigned char *buf, size_t len)
36 struct cookie *c = f->cookie;
37 size_t rem = c->len - c->pos;
38 if (c->pos > c->len) rem = 0;
43 memcpy(buf, c->buf+c->pos, len);
46 if (rem > f->buf_size) rem = f->buf_size;
48 f->rend = f->buf + rem;
49 memcpy(f->rpos, c->buf+c->pos, rem);
54 static size_t mwrite(FILE *f, const unsigned char *buf, size_t len)
56 struct cookie *c = f->cookie;
58 size_t len2 = f->wpos - f->wbase;
61 if (mwrite(f, f->wpos, len2) < len2) return 0;
63 if (c->mode == 'a') c->pos = c->len;
64 rem = c->size - c->pos;
65 if (len > rem) len = rem;
66 memcpy(c->buf+c->pos, buf, len);
68 if (c->pos > c->len) {
70 if (c->len < c->size) c->buf[c->len] = 0;
71 else if ((f->flags&F_NORD) && c->size) c->buf[c->size-1] = 0;
76 static int mclose(FILE *m)
81 FILE *fmemopen(void *restrict buf, size_t size, const char *restrict mode)
84 int plus = !!strchr(mode, '+');
86 if (!strchr("rwa", *mode)) {
91 if (!buf && size > PTRDIFF_MAX) {
96 f = malloc(sizeof *f + (buf?0:size));
98 memset(&f->f, 0, sizeof f->f);
102 f->f.buf = f->buf + UNGET;
103 f->f.buf_size = sizeof f->buf - UNGET;
106 memset(buf, 0, size);
109 memset(&f->c, 0, sizeof f->c);
114 if (!plus) f->f.flags = (*mode == 'r') ? F_NOWR : F_NORD;
115 if (*mode == 'r') f->c.len = size;
116 else if (*mode == 'a') f->c.len = f->c.pos = strnlen(buf, size);
117 else if (plus) *f->c.buf = 0;
124 if (!libc.threaded) f->f.lock = -1;
126 return __ofl_add(&f->f);