linkinfo

(PHP 4, PHP 5)

linkinfo — Gets information about a link

Description

int linkinfo ( string $path )

Gets information about a link.

This function is used to verify if a link (pointed to by path) really exists (using the same method as the S_ISLNK macro defined in stat.h).

Parameters

path: Path to the link.

Return Values

linkinfo() returns the st_dev field of the Unix C stat structure returned by the lstat system call. Returns 0 or FALSE in case of error.

Changelog

Version	Description
5.3.0	This function is now available on Windows platforms (Vista, Server 2008 or greater).

Examples

Example #1 linkinfo() example


<?php

echo linkinfo('/vmlinuz'); // 835

?>


I expected this function to return FALSE or 0 if a symbolic link did not exist (per the documentation above), but that's not what happened. Reading the man page for the Linux kerne's stat call here: http://www.kernel.org/doc/man-pages/online/pages/man2/stat.2.html it says this:



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



... which is what is happening in my case. I am doing a linkinfo('/path/to/file'); on a missing symlink, and I get back a value of -1. As we know, a value of -1 is not going to evaluate to a FALSE or 0.



My point - be careful with return values for missing symlinks.

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