readlink
(PHP 4, PHP 5)
readlink — Returns the target of a symbolic link
Description
string readlink
( string
$path
)readlink() does the same as the readlink C function.
Parameters
-
path -
The symbolic link path.
Changelog
| Version | Description |
|---|---|
| 5.3.0 | This function is now available on Windows platforms (Vista, Server 2008 or greater). |
Return Values
Returns the contents of the symbolic link path or FALSE on error.
Examples
Example #1 readlink() example
<?php
// output e.g. /boot/vmlinux-2.4.20-xfs
echo readlink('/vmlinuz');
?>
See Also
- is_link() - Tells whether the filename is a symbolic link
- symlink() - Creates a symbolic link
- linkinfo() - Gets information about a link
- PHP Руководство
- Функции по категориям
- Индекс функций
- Справочник функций
- Расширения для работы с файловой системой
- Функции для работы с файловой системой
- basename
- chgrp
- chmod
- chown
- clearstatcache
- copy
- delete
- dirname
- disk_free_space
- disk_total_space
- diskfreespace
- fclose
- feof
- fflush
- fgetc
- fgetcsv
- fgets
- fgetss
- file_exists
- file_get_contents
- file_put_contents
- file
- fileatime
- filectime
- filegroup
- fileinode
- filemtime
- fileowner
- fileperms
- filesize
- filetype
- flock
- fnmatch
- fopen
- fpassthru
- fputcsv
- fputs
- fread
- fscanf
- fseek
- fstat
- ftell
- ftruncate
- fwrite
- glob
- is_dir
- is_executable
- is_file
- is_link
- is_readable
- is_uploaded_file
- is_writable
- is_writeable
- lchgrp
- lchown
- link
- linkinfo
- lstat
- mkdir
- move_uploaded_file
- parse_ini_file
- parse_ini_string
- pathinfo
- pclose
- popen
- readfile
- readlink
- realpath_cache_get
- realpath_cache_size
- realpath
- rename
- rewind
- rmdir
- set_file_buffer
- stat
- symlink
- tempnam
- tmpfile
- touch
- umask
- unlink
Коментарии
This will trigger a warning and return false if you pass it a non-symlink. If the file doesn't exist, it will trigger a differently worded warning.
mslade@jupiter ~$ touch a
mslade@jupiter ~$ ln -s a b
mslade@jupiter ~$ ls -l {a,b}
-rw------- 1 mslade mslade 0 2009-06-10 15:27 a
lrwxrwxrwx 1 mslade mslade 1 2009-06-10 15:27 b -> a
mslade@jupiter ~$ php -r "var_dump(readlink('b'));"
string(1) "a"
mslade@jupiter ~$ php -r "var_dump(readlink('a'));"
Warning: readlink(): Invalid argument in Command line code on line 1
bool(false)
mslade@jupiter ~$ php -r "var_dump(readlink('c'));"
Warning: readlink(): No such file or directory in Command line code on line 1
bool(false)
A little function to readlink TO THE END:
(realpath can't do this if the symlink (ultimately) points to a non-existing path, since it just returns false in this case.)
function readlinkToEnd($linkFilename) {
if(!is_link($linkFilename)) return $linkFilename;
$final = $linkFilename;
while(true) {
$target = readlink($final);
if(substr($target, 0, 1)=='/') $final = $target;
else $final = dirname($final).'/'.$target;
if(substr($final, 0, 2)=='./') $final = substr($final, 2);
if(!is_link($final)) return $final;
}
}
A little function to readlink TO THE END:
(realpath can't do this if the symlink (ultimately) points to a non-existing path, since it just returns false in this case.)
function readlinkToEnd($linkFilename) {
if(!is_link($linkFilename)) return $linkFilename;
$final = $linkFilename;
while(true) {
$target = readlink($final);
if(substr($target, 0, 1)=='/') $final = $target;
else $final = dirname($final).'/'.$target;
if(substr($final, 0, 2)=='./') $final = substr($final, 2);
if(!is_link($final)) return $final;
}
}