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preg_last_error

(PHP 5 >= 5.2.0, PHP 7)

preg_last_errorRetourne le code erreur de la dernière expression PCRE exécutée

Description

preg_last_error ( void ) : int

Retourne le code erreur de la dernière regex PCRE exécutée.

Exemple #1 Exemple avec preg_last_error()

<?php

preg_match
('/(?:\D+|<\d+>)*[!?]/''foobar foobar foobar');

if (
preg_last_error() == PREG_BACKTRACK_LIMIT_ERROR) {
    print 
'Backtrack limit was exhausted!';
}

?>

L'exemple ci-dessus va afficher :

Backtrack limit was exhausted!

Valeurs de retour

Retourne une des constantes suivantes (expliquées sur cette page):

  • PREG_NO_ERROR
  • PREG_INTERNAL_ERROR
  • PREG_BACKTRACK_LIMIT_ERROR (voir aussi pcre.backtrack_limit)
  • PREG_RECURSION_LIMIT_ERROR (voir aussi pcre.recursion_limit)
  • PREG_BAD_UTF8_ERROR
  • PREG_BAD_UTF8_OFFSET_ERROR (depuis PHP 5.3.0)
  • PREG_JIT_STACKLIMIT_ERROR (depuis PHP 7.0.0)

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User Contributed Notes 8 notes

up
17
gk at anuary dot com
5 years ago
In PHP 5.5 and above, getting the error message is as simple as:

<?php
echo array_flip(get_defined_constants(true)['pcre'])[preg_last_error()];
up
10
andre at koethur dot de
6 years ago
Here is a more advanced function to convert an error code to text:

<?php

function preg_errtxt($errcode)
{
    static
$errtext;

    if (!isset(
$errtxt))
    {
       
$errtext = array();
       
$constants = get_defined_constants(true);
        foreach (
$constants['pcre'] as $c => $n) if (preg_match('/_ERROR$/', $c)) $errtext[$n] = $c;
    }

    return
array_key_exists($errcode, $errtext)? $errtext[$errcode] : NULL;
}

?>
up
1
eu at ericruiz dot com dot br
2 years ago
Take it into account before use this function.

My php --version
PHP 5.6.29 (cli) (built: Dec  8 2016 09:19:46)
Copyright (c) 1997-2016 The PHP Group
Zend Engine v2.6.0, Copyright (c) 1998-2016 Zend Technologies

On Linux Fedora 23 4.8.13-100.fc23.x86_64 #1 SMP Fri Dec 9 14:51:40 UTC 2016 x86_64 x86_64 x86_64 GNU/Linux

<?php
// @see http://stackoverflow.com/questions/4440626/how-can-i-validate-regex

// returns true because  there is no opening "(" for the closing ")"
var_dump(preg_match('~InvalidRegular)Expression~', null) === false);

// this SHOULD be something different from 0, but...
var_dump(preg_last_error());
?>
up
3
johan at bluemoonit dot net
9 years ago
The above function pcre_error_deocde [sic] is not correct - not all of the used constants are errors constants. For example, when the error is actually PREG_BAD_UTF8_ERROR, the function outputs the text for PREG_SPLIT_OFFSET_CAPTURE.
up
1
andre at koethur dot de
6 years ago
Just an addition to my previous note: In unicode mode (with "u" modifier), PREG_BAD_UTF8_ERROR only reflects errors in the subject string. If the pattern itself contains invalid characters, preg_match() (or preg_match_all()) returns false but preg_last_error() returns 0 indicating PREG_NO_ERROR. Instead, php issues a warning: "preg_match(): Compilation failed: invalid UTF-8 string at offset 0"
up
0
Daniel Klein
1 day ago
Here is a correction to one of the previous "get error message" snippets. It filters out the non-error codes which stops "Warning:  array_flip(): Can only flip STRING and INTEGER values!" from being emitted due to ["PCRE_JIT_SUPPORT"]=>bool(true):

<?php
echo array_flip(array_filter(get_defined_constants(true)['pcre'], function ($value) {
  return
substr($value, -6) === '_ERROR';
},
ARRAY_FILTER_USE_KEY))[preg_last_error()];
up
0
Vladimir Valikaev
8 days ago
Getting error as text (small update):

<?php
echo array_flip(array_filter(get_defined_constants(true)['pcre'], function($v) { return is_integer($v); }))[preg_last_error()];
up
0
Anonymous
13 days ago
If you use T-Regx library, to get the last constant, you can use

<?php

echo preg_last_error_constant(); // 'PREG_BAD_UTF8_ERROR'
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