incubator-nuttx/libs/libc/unistd/lib_chdir.c

163 lines
4.4 KiB
C

/****************************************************************************
* libs/libc/unistd/lib_chdir.c
*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership. The
* ASF licenses this file to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance with the
* License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations
* under the License.
*
****************************************************************************/
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#include <sys/stat.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <errno.h>
#include "libc.h"
#ifndef CONFIG_DISABLE_ENVIRON
/****************************************************************************
* Private Functions
****************************************************************************/
/****************************************************************************
* Name: _trimdir
****************************************************************************/
#if 0
static inline void _trimdir(char *path)
{
/* Skip any trailing '/' characters (unless it is also the leading '/') */
int len = strlen(path) - 1;
while (len > 0 && path[len] == '/')
{
path[len] = '\0';
len--;
}
}
#else
# define _trimdir(p)
#endif
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: chdir
*
* Description:
* The chdir() function causes the directory named by the pathname pointed
* to by the 'path' argument to become the current working directory; that
* is, the starting point for path searches for pathnames not beginning
* with '/'.
*
* Input Parameters:
* path - A pointer to a directory to use as the new current working
* directory
*
* Returned Value:
* 0(OK) on success; -1(ERROR) on failure with errno set appropriately:
*
* EACCES
* Search permission is denied for any component of the pathname.
* ELOOP
* A loop exists in symbolic links encountered during resolution of the
* 'path' argument OR more that SYMLOOP_MAX symbolic links in the
* resolution of the 'path' argument.
* ENAMETOOLONG
* The length of the path argument exceeds PATH_MAX or a pathname
* component is longer than NAME_MAX.
* ENOENT
* A component of 'path' does not name an existing directory or path is
* an empty string.
* ENOTDIR
* A component of the pathname is not a directory.
*
****************************************************************************/
int chdir(FAR const char *path)
{
struct stat buf;
char *oldpwd;
char *alloc;
int errcode;
int ret;
/* Verify the input parameters */
if (!path)
{
errcode = ENOENT;
goto errout;
}
/* Verify that 'path' refers to a directory */
ret = stat(path, &buf);
if (ret != 0)
{
errcode = ENOENT;
goto errout;
}
/* Something exists here... is it a directory? */
if (!S_ISDIR(buf.st_mode))
{
errcode = ENOTDIR;
goto errout;
}
/* Yes, it is a directory.
* Remove any trailing '/' characters from the path
*/
_trimdir(path);
/* Replace any preceding OLDPWD with the current PWD (this is to
* support 'cd -' in NSH)
*/
sched_lock();
oldpwd = getenv("PWD");
if (!oldpwd)
{
oldpwd = CONFIG_LIBC_HOMEDIR;
}
alloc = strdup(oldpwd); /* kludge needed because environment is realloc'ed */
setenv("OLDPWD", alloc, TRUE);
lib_free(alloc);
/* Set the cwd to the input 'path' */
setenv("PWD", path, TRUE);
sched_unlock();
return OK;
errout:
set_errno(errcode);
return ERROR;
}
#endif /* !CONFIG_DISABLE_ENVIRON */