sortix-mirror/libc/read.cpp

44 lines
1.3 KiB
C++

/*******************************************************************************
Copyright(C) Jonas 'Sortie' Termansen 2011, 2012.
This file is part of the Sortix C Library.
The Sortix C Library 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 3 of the License, or (at your
option) any later version.
The Sortix C Library 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 the Sortix C Library. If not, see <http://www.gnu.org/licenses/>.
read.cpp
Reads from a file descriptor.
*******************************************************************************/
#include <sys/syscall.h>
#include <errno.h>
#include <unistd.h>
DEFN_SYSCALL3(ssize_t, SysRead, SYSCALL_READ, int, void*, size_t);
extern "C" ssize_t read(int fd, void* buf, size_t count)
{
retry:
ssize_t result = SysRead(fd, buf, count);
if ( result < 0 && errno == EAGAIN ) { goto retry; }
return result;
}
extern "C" ssize_t pread(int, void*, size_t, off_t)
{
errno = ENOSYS;
return -1;
}