Files
libite/src/fsendfile.c
T
Joachim Wiberg 6537b11e34 doc: initial effort to enable doxygen
Framework from libuEv.

Signed-off-by: Joachim Wiberg <troglobit@gmail.com>
2021-10-03 19:08:40 +02:00

93 lines
2.5 KiB
C

/* Copy data between file streams
*
* Copyright (c) 2013 Tobias Waldekranz <tobias@waldekranz.com>
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
/**
* @file fsendfile.c
* @author Tobias Waldekranz
* @date 2013
* @copyright MIT License
*/
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
/**
* Copy data between file streams.
* @param src Source stream
* @param dst Destination stream
* @param len Number of bytes to copy
*
* The @p dst argument may be @c NULL, in which case @a len bytes are
* read and discarded from @a src. This can be useful for streams where
* seeking is not permitted. Additionally, @a len may be the special
* value zero (0), in which case fsendfile() copies until @c EOF is seen
* on @a src.
*
* @returns The number of bytes copied. If an error is detected -1 is
* returned and @a errno will be set accordingly.
*/
ssize_t fsendfile(FILE *src, FILE *dst, size_t len)
{
char *buf;
size_t tot = 0;
ssize_t blk = BUFSIZ, num = 0;
if (!src) {
errno = EINVAL;
return -1;
}
buf = malloc(BUFSIZ);
if (!buf)
return -1;
while (!len || tot < len) {
if (len && ((len - tot) < BUFSIZ))
blk = len - tot;
num = fread(buf, 1, blk, src);
if (num == 0)
break;
if (dst && (fwrite(buf, num, 1, dst) != 1)) {
num = -1;
break;
}
tot += num;
}
free(buf);
return (num == -1) ? -1 : (ssize_t)tot;
}
/**
* Local Variables:
* indent-tabs-mode: t
* c-file-style: "linux"
* End:
*/