win_is_writable( string $path ): bool
- Since
- 2.8.0
- Source
wp-includes/functions.php:2302
Description
PHP has issues with Windows ACL's for determine if a directory is writable or not, this works around them by checking the ability to open files rather than relying upon PHP to interpret the OS ACL.
Compatibility
- WordPress
- since 2.8.0
- PHP
- 7.4–8.6-dev
- 6.7.7
- 6.8.8
- 6.9.7
- 7.0.4
- 7.1.0
Present in every tracked release (6.7.7 to 7.1.0), and compiles on PHP 7.4 through 8.6-dev.
Parameters
$pathstring- Windows path to check for write-ability.
Return value
bool- Whether the path is writable.
Performance profile
How much work a call to win_is_writable() does, and what it touches: the algorithmic scaling, the Zend instruction count per call across PHP versions, the hooks it hands control to, and the core code that calls it. Measured from the compiled opcodes, not a stopwatch, so every number is identical on any machine running the same PHP version, and every function in core is ranked by cost.
- Cost class
- Heavy
- Scaling
- Constant
- Instructions
- 17–31
- Plugin surface
- None
- Called by
- 3
Reads or writes the filesystem via is_dir().
No loop in the body: the same number of instructions runs whatever you pass in.
Executed per call on PHP 8.5, depending on the branch taken. The body compiles to 55.
Nothing here hands control to plugin code.
3 places in core call this, so the cost is paid more often than your own code shows.
What it touches
- filesystemfilesystem access
is_dir()called directly
What one call costs · 5 distinct outcomes
One number would be a lie: the work depends on which branch runs. These are every distinct cost win_is_writable() can have, taken from its control-flow graph on PHP 8.5.
| When | Instructions | Calls it makes |
|---|---|---|
| always | 17 | mt_rand(), uniqid(), win_is_writable() |
is_dir() | 22 | is_dir(), mt_rand(), uniqid(), win_is_writable() |
!is_dir() && $f === false | 24 | is_dir(), file_exists(), fopen() |
!is_dir() && $f !== false && $value | 28 | is_dir(), file_exists(), fopen(), fclose() |
!is_dir() && $f !== false && !$value | 31 | is_dir(), file_exists(), fopen(), fclose(), unlink() |
Across PHP versions
Compiles the same on PHP 7.4, 8.1, 8.2, 8.3, 8.4, 8.5 and 8.6-dev: 55 instructions, 17–31 executed per call, 4 branches. The work does not change between versions.
An instruction is not a fixed amount of time, so a matching count is not necessarily the same speed; what it rules out is a difference in the work itself.
Uses · 1
- win_is_writable()Workaround for Windows bug in is_writable() function
Used by · 3
- iis7_save_url_rewrite_rules()Updates the IIS web.config file with the current rules if it is writable.
- win_is_writable()Workaround for Windows bug in is_writable() function
- wp_is_writable()Determines if a directory is writable.
Source code
function win_is_writable( $path ) { if ( '/' === $path[ strlen( $path ) - 1 ] ) { // If it looks like a directory, check a random file within the directory. return win_is_writable( $path . uniqid( mt_rand() ) . '.tmp' ); } elseif ( is_dir( $path ) ) { // If it's a directory (and not a file), check a random file within the directory. return win_is_writable( $path . '/' . uniqid( mt_rand() ) . '.tmp' ); } // Check tmp file for read/write capabilities. $should_delete_tmp_file = ! file_exists( $path ); $f = @fopen( $path, 'a' ); if ( false === $f ) { return false; } fclose( $f ); if ( $should_delete_tmp_file ) { unlink( $path ); } return true;}Changelog
Introduced in 2.8.0. Unchanged from 6.7.7 through 7.1.0.
Signature, return type and hooks compared across 5 parsed releases.
About this page
- Parsed data
- Generated from the wordpress-develop 7.0.4 tag, from
src/wp-includes/functions.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it. - Corrections
- Something wrong on this page? Report it and it gets fixed in the next regeneration.