jehanne/sys/src/lib/jehanne/9sys/getwd.c

46 lines
1.2 KiB
C

/*
* This file is part of Jehanne.
*
* Copyright (C) 2016 Giacomo Tesio <giacomo@tesio.it>
*
* Jehanne is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, version 2 of the License.
*
* Jehanne 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with Jehanne. If not, see <http://www.gnu.org/licenses/>.
*/
#include <u.h>
#include <libc.h>
/* Fills buf with the current workking directory.
*
* Returns
* - 0 on error
* - the negated length of the working directory path if nbuf is too small
* - the (positive) length of the working directory on success
*/
long
jehanne_getwd(char *buf, int nbuf)
{
long n;
int fd;
fd = sys_open("#0/wdir", OREAD);
if(fd < 0)
return 0;
n = jehanne_read(fd, nil, -1);
if(n == ~0) /* an error occurred */
return 0;
if(nbuf >= ~n)
n = jehanne_read(fd, buf, nbuf);
sys_close(fd);
return n;
}