1 #include "stdio_impl.h"
18 unsigned char buf[BUFSIZ];
21 static off_t ms_seek(FILE *f, off_t off, int whence)
24 struct cookie *c = f->cookie;
30 base = (size_t [3]){0, c->pos, c->len}[whence];
31 if (off < -base || off > SSIZE_MAX-base) goto fail;
32 return c->pos = base+off;
35 static size_t ms_write(FILE *f, const unsigned char *buf, size_t len)
37 struct cookie *c = f->cookie;
38 size_t len2 = f->wpos - f->wbase;
42 if (ms_write(f, f->wbase, len2) < len2) return 0;
44 if (len + c->pos >= c->space) {
45 len2 = 2*c->space+1 | c->pos+len+1;
46 newbuf = realloc(c->buf, len2);
47 if (!newbuf) return 0;
48 *c->bufp = c->buf = newbuf;
49 memset(c->buf + c->space, 0, len2 - c->space);
52 memcpy(c->buf+c->pos, buf, len);
54 if (c->pos >= c->len) c->len = c->pos;
59 static int ms_close(FILE *f)
64 FILE *open_memstream(char **bufp, size_t *sizep)
69 if (!(f=malloc(sizeof *f))) return 0;
70 if (!(buf=malloc(sizeof *buf))) {
74 memset(&f->f, 0, sizeof f->f);
75 memset(&f->c, 0, sizeof f->c);
80 f->c.pos = f->c.len = f->c.space = *sizep = 0;
81 f->c.buf = *bufp = buf;
87 f->f.buf_size = sizeof f->buf;
89 f->f.write = ms_write;
91 f->f.close = ms_close;
93 if (!libc.threaded) f->f.lock = -1;
95 return __ofl_add(&f->f);