mbstring_binary_safe_encoding( bool $reset = false )
- Since
- 3.7.0
- Source
wp-includes/functions.php:7600
Description
When mbstring.func_overload is in use for multi-byte encodings, the results from strlen() and similar functions respect the utf8 characters, causing binary data to return incorrect lengths.
This function overrides the mbstring encoding to a binary-safe encoding, and resets it to the users expected encoding afterwards through the reset_mbstring_encoding function.
It is safe to recursively call this function, however each mbstring_binary_safe_encoding() call must be followed up with an equal number of reset_mbstring_encoding() calls.
Compatibility
- WordPress
- since 3.7.0
- 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
$resetbooloptional- Whether to reset the encoding back to a previously-set encoding.
Default false.Default:false
Performance profile
How much work a call to mbstring_binary_safe_encoding() 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
- Trivial
- Scaling
- Constant
- Instructions
- 8–36
- Plugin surface
- None
- Called by
- 13
Touches nothing outside its own arguments.
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 38.
Nothing here hands control to plugin code.
13 places in core call this, so the cost is paid more often than your own code shows.
What one call costs · 8 distinct outcomes
One number would be a lie: the work depends on which branch runs. These are every distinct cost mbstring_binary_safe_encoding() can have, taken from its control-flow graph on PHP 8.5.
| When | Instructions | Calls it makes |
|---|---|---|
$overloaded !== null | 8–10 | none |
$overloaded === null | 15–18 | ini_get() |
$overloaded !== null && $overloaded !== false | 17 | array_pop(), mb_internal_encoding() |
$overloaded !== null && $overloaded !== false | 20–21 | mb_internal_encoding(), array_push(), mb_internal_encoding() |
$overloaded === null && $overloaded !== false | 24–25 | ini_get(), array_pop(), mb_internal_encoding() |
$overloaded === null && $overloaded !== false | 27–29 | ini_get(), mb_internal_encoding(), array_push(), mb_internal_encoding() |
$overloaded !== null && $overloaded !== false | 28 | mb_internal_encoding(), array_push(), mb_internal_encoding(), array_pop(), mb_internal_encoding() |
$overloaded === null && $overloaded !== false | 35–36 | ini_get(), mb_internal_encoding(), array_push(), mb_internal_encoding(), array_pop(), mb_internal_encoding() |
Across PHP versions
| PHP | Compiled | Executed | Branches | Notes |
|---|---|---|---|---|
| 8.6-dev | 42 | 8–40 | 7 | 4 more instructions than PHP 8.5 |
| 8.5 | 38 | 8–36 | 6 | |
| 8.4 | 38 | 8–36 | 6 | |
| 8.3 | 38 | 8–36 | 6 | |
| 8.2 | 38 | 8–36 | 6 | |
| 8.1 | 38 | 8–36 | 6 | 8 more instructions than PHP 7.4 |
| 7.4 | 30 | 8–29 | 5 |
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.
Used by · 13
- WP_Filesystem_Direct::put_contents()Writes a string to a file.
- WP_Filesystem_FTPext::put_contents()Writes a string to a file.
- WP_Filesystem_ftpsockets::dirlist()Gets details for files in a directory or a specific file.
- WP_Filesystem_ftpsockets::get_contents()Reads entire file into a string.
- WP_Filesystem_ftpsockets::put_contents()Writes a string to a file.
- WP_Http::request()Send an HTTP request to a URI.
- _unzip_file_pclzip()Attempts to unzip an archive using the PclZip library.
- reset_mbstring_encoding()Resets the mbstring internal encoding to a users previously set encoding.
- seems_utf8()Checks to see if a string is utf8 encoded.
- utf8_uri_encode()Encodes the Unicode values to be used in the URI.
- verify_file_signature()Verifies the contents of a file against its ED25519 signature.
- wp_read_image_metadata()Gets extended image metadata, exif or iptc as available.
Show all 13
- wpdb::strip_invalid_text()Strips any invalid characters based on value/charset pairs.
Source code
function mbstring_binary_safe_encoding( $reset = false ) { static $encodings = array(); static $overloaded = null; if ( is_null( $overloaded ) ) { if ( function_exists( 'mb_internal_encoding' ) && ( (int) ini_get( 'mbstring.func_overload' ) & 2 ) // phpcs:ignore PHPCompatibility.IniDirectives.RemovedIniDirectives.mbstring_func_overloadDeprecated ) { $overloaded = true; } else { $overloaded = false; } } if ( false === $overloaded ) { return; } if ( ! $reset ) { $encoding = mb_internal_encoding(); array_push( $encodings, $encoding ); mb_internal_encoding( 'ISO-8859-1' ); } if ( $reset && $encodings ) { $encoding = array_pop( $encodings ); mb_internal_encoding( $encoding ); }}Changelog
Introduced in 3.7.0. Unchanged from 6.7.7 through 7.1.0.
Signature, return type and hooks compared across 5 parsed releases.
About this page
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