1
mirror of https://code.videolan.org/videolan/vlc synced 2024-07-25 09:41:30 +02:00
vlc/compat/writev.c
2022-07-03 17:31:24 +00:00

73 lines
2.0 KiB
C

/*****************************************************************************
* writev.c: POSIX writev() replacement
*****************************************************************************
* Copyright © 2022 Rémi Denis-Courmont
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU Lesser General Public License as published by
* the Free Software Foundation; either version 2.1 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this program; if not, write to the Free Software Foundation,
* Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
*****************************************************************************/
#ifdef HAVE_CONFIG_H
# include <config.h>
#endif
#include <errno.h>
#include <stdlib.h>
#include <string.h>
#ifdef _WIN32
# include <io.h>
#else
# include <unistd.h>
#endif
ssize_t writev(int fd, const struct iovec *iov, int iovcnt)
{
if (iovcnt == 1)
return write(fd, iov->iov_base, iov->iov_len);
size_t size = 0;
for (int i = 0; i < iovcnt; i++) {
/* TODO: use ckd_add() */
size += iov[i].iov_len;
if (iov[i].iov_len > size) {
errno = EINVAL;
return -1;
}
}
void *buf = malloc(size ? size : 1);
if (buf == NULL) {
errno = ENOBUFS;
return -1;
}
unsigned char *ptr = buf;
for (int i = 0; i < iovcnt; i++) {
memcpy(ptr, iov->iov_base, iov->iov_len);
ptr += iov->iov_len;
iov++;
}
ssize_t bytes = write(fd, buf, size);
int saved_errno = errno;
free(buf);
errno = saved_errno;
return bytes;
}