namei.c File Reference

Implementation of functions fcntl() and open(). More...

Macros
#define	__DEBUG_HEADER__   "[NAMEI ]"
	Change header.
#define	__DEBUG_LEVEL__   LOGLEVEL_NOTICE
	Set log level.
#define	APPEND_PATH_SEPARATOR(buffer, buflen)
	Appends the path with a "/" as separator. More...
#define	APPEND_PATH(buffer, token)
	Appends the path. More...

Functions
int	sys_unlink (const char *path)
	Delete a name and possibly the file it refers to. More...
int	sys_mkdir (const char *path, mode_t mode)
	Creates a new directory at the given path. More...
int	sys_rmdir (const char *path)
	Removes the given directory. More...
int	sys_creat (const char *path, mode_t mode)
	Creates a new file or rewrite an existing one. More...
int	sys_symlink (const char *linkname, const char *path)
	Creates a symbolic link. More...
int	sys_readlink (const char *path, char *buffer, size_t bufsize)
	Read the symbolic link, if present. More...
char *	realpath (const char *path, char *buffer, size_t buflen)
	Return the canonicalized absolute pathname. More...
static int	__is_a_link (const char *path)
	Determines if the path points to a link. More...
static int	__get_link_content (const char *path, char *buffer, size_t buflen)
	Returns the content of the link. More...
int	__resolve_path (const char *path, char *abspath, size_t buflen, int flags, int link_depth)
	Resolve the path by following all symbolic links. More...
int	resolve_path (const char *path, char *buffer, size_t buflen, int flags)

Detailed Description

Implementation of functions fcntl() and open().

Copyright

(c) 2014-2024 This file is distributed under the MIT License. See LICENSE.md for details.

Macro Definition Documentation

APPEND_PATH

#define APPEND_PATH	(		buffer,
			token
	)

Value:

    {                                          \
        strncat(buffer, token, strlen(token)); \
    }

Appends the path.

APPEND_PATH_SEPARATOR

#define APPEND_PATH_SEPARATOR	(		buffer,
			buflen
	)

Value:

    {                                                                                     \
        if (buffer[strnlen(buffer, buflen) - 1] != '/') { strncat(buffer, "/", buflen); } \
    }

Appends the path with a "/" as separator.

Function Documentation

__get_link_content()

static int __get_link_content ( const char *  path, char *  buffer, size_t  buflen  )

inlinestatic

Returns the content of the link.

Parameters

path	the path to the file.
buffer	the buffer where we store the link content.
buflen	length of the buffer.

Returns

the length of the link, or a negative value on error.

__is_a_link()

static int __is_a_link ( const char *  path )

inlinestatic

Determines if the path points to a link.

Parameters

path	the path to the file.

Returns

1 if it is a link, 0 otherwise.

__resolve_path()

int __resolve_path	(	const char *	path,
		char *	abspath,
		size_t	buflen,
		int	flags,
		int	link_depth
	)

Resolve the path by following all symbolic links.

Parameters

path	the path to resolve.
abspath	the buffer where the resolved path is stored.
buflen	the size of the provided resolved_path buffer.
flags	the flags controlling how the path is resolved.
link_depth	the current link depth.

Returns

-errno on fail, 1 on success.

realpath()

char* realpath	(	const char *	path,
		char *	buffer,
		size_t	buflen
	)

Return the canonicalized absolute pathname.

Parameters

path	the path we are canonicalizing.
buffer	where we will store the canonicalized path.
buflen	the size of the buffer.

Returns

If there is no error, realpath() returns a pointer to the buffer. Otherwise, it returns NULL, the contents of the array buffer are undefined, and errno is set to indicate the error.

sys_creat()

int sys_creat	(	const char *	path,
		mode_t	mode
	)

Creates a new file or rewrite an existing one.

Parameters

path	path to the file.
mode	mode for file creation.

Returns

file descriptor number, -1 otherwise and errno is set to indicate the error.

It is equivalent to: open(path, O_WRONLY|O_CREAT|O_TRUNC, mode)

sys_mkdir()

int sys_mkdir	(	const char *	path,
		mode_t	mode
	)

Creates a new directory at the given path.

Parameters

path	The path of the new directory.
mode	The permission of the new directory.

Returns

Returns a negative value on failure.

sys_readlink()

int sys_readlink	(	const char *	path,
		char *	buffer,
		size_t	bufsize
	)

Read the symbolic link, if present.

Parameters

path	the file for which we want to read the symbolic link information.
buffer	the buffer where we will store the symbolic link path.
bufsize	the size of the buffer.

Returns

The number of read characters on success, -1 otherwise and errno is set to indicate the error.

sys_rmdir()

int sys_rmdir

(

const char *

path

)

Removes the given directory.

Parameters

path	The path to the directory to remove.

Returns

Returns a negative value on failure.

sys_symlink()

int sys_symlink	(	const char *	linkname,
		const char *	path
	)

Creates a symbolic link.

Parameters

linkname	the name of the link.
path	the entity it is linking to.

Returns

0 on success, a negative number if fails and errno is set.

sys_unlink()

int sys_unlink

(

const char *

path

)

Delete a name and possibly the file it refers to.

Parameters

path	A pathname for a file.

Returns

On success, zero is returned. On error, -1 is returned, and errno is set appropriately.