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| | #define _GNU_SOURCE
#include "stdio_impl.h"
#include <stdlib.h>
#include <sys/ioctl.h>
#include <fcntl.h>
#include <errno.h>
#include <string.h>
struct fcookie {
void *cookie;
cookie_io_functions_t iofuncs;
};
static size_t cookieread(FILE *f, unsigned char *buf, size_t len)
{
struct fcookie *fc = f->cookie;
size_t ret, remain = len, readlen = 0;
if (fc->iofuncs.read == NULL) return 0;
ret = fc->iofuncs.read(fc->cookie, (char *) buf, len - 1);
if (ret == 0) goto bail_eof;
readlen += ret;
remain -= ret;
f->rpos = f->buf;
ret = fc->iofuncs.read(fc->cookie, (char *) f->rpos, f->buf_size);
if (ret == 0) goto bail_eof;
f->rend = f->rpos + ret;
if (remain > f->buf_size) remain = f->buf_size;
memcpy(buf + readlen, f->rpos, remain);
readlen += remain;
f->rpos += remain;
return readlen;
bail_eof:
f->flags |= F_EOF;
f->rpos = f->rend = f->buf;
return readlen;
}
static size_t cookiewrite(FILE *f, const unsigned char *buf, size_t len)
{
struct fcookie *fc = f->cookie;
size_t ret;
size_t len2 = f->wpos - f->wbase;
if (fc->iofuncs.write == NULL) return 0;
if (len2) {
f->wpos = f->wbase;
if (cookiewrite(f, f->wpos, len2) < len2) return 0;
}
return fc->iofuncs.write(fc->cookie, (const char *) buf, len);
}
static off_t cookieseek(FILE *f, off_t off, int whence)
{
struct fcookie *fc = f->cookie;
if (fc->iofuncs.seek) return fc->iofuncs.seek(fc->cookie, &off, whence);
return -1;
}
static int cookieclose(FILE *f)
{
struct fcookie *fc = f->cookie;
if (fc->iofuncs.close) return fc->iofuncs.close(fc->cookie);
return 0;
}
FILE *fopencookie(void *cookie, const char *mode, cookie_io_functions_t iofuncs)
{
FILE *f;
struct fcookie *fc;
/* Check for valid initial mode character */
if (!strchr("rwa", *mode)) {
errno = EINVAL;
return 0;
}
/* Allocate FILE+fcookie+buffer or fail */
if (!(f=malloc(sizeof *f + sizeof *fc + UNGET + BUFSIZ))) return 0;
/* Zero-fill only the struct, not the buffer */
memset(f, 0, sizeof *f);
/* Impose mode restrictions */
if (!strchr(mode, '+')) f->flags = (*mode == 'r') ? F_NOWR : F_NORD;
/* Set up our fcookie */
fc = (void *)(f + 1);
fc->cookie = cookie;
fc->iofuncs.read = iofuncs.read;
fc->iofuncs.write = iofuncs.write;
fc->iofuncs.seek = iofuncs.seek;
fc->iofuncs.close = iofuncs.close;
f->fd = -1;
f->cookie = fc;
f->buf = (unsigned char *)f + sizeof *f + sizeof *fc + UNGET;
f->buf_size = BUFSIZ;
f->lbf = EOF;
f->lock = 0;
/* Initialize op ptrs. No problem if some are unneeded. */
f->read = cookieread;
f->write = cookiewrite;
f->seek = cookieseek;
f->close = cookieclose;
/* Add new FILE to open file list */
return __ofl_add(f);
}
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