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Top Forums Shell Programming and Scripting Regex issue with \s in character class. Post 303042656 by Scrutinizer on Thursday 2nd of January 2020 08:56:49 AM
Old 01-02-2020
Quote:
Originally Posted by Neo
Also, another FWIW:

Code:
linux# php -a
Interactive mode enabled

php > $a = ' FOO ';
php > echo preg_match('/[\s][A-Z]+[\s]/', $a,$matches);
1
php > echo $matches[0];
 FOO 
php >

so, it works in a PHP REGEX .....
POSIX regular expressions (BRE/ERE) and the GNU and BSD derivatives are the exception, rather than the norm, in that \ is not special/meta within a character class (bracket) expression.

In (I think all) other regex flavours \ is special in a character class (bracket) expression.


--
Shortcuts like \s are not part of POSIX BRE/ERE, but are supported as an extension in BSD and GNU implementations.

Last edited by Scrutinizer; 01-02-2020 at 10:04 AM..
 

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DEBUG_PRINT_BACKTRACE(3)						 1						  DEBUG_PRINT_BACKTRACE(3)

debug_print_backtrace - Prints a backtrace

SYNOPSIS
void debug_print_backtrace ([int $options], [int $limit]) DESCRIPTION
debug_print_backtrace(3) prints a PHP backtrace. It prints the function calls, included/required files and eval(3)ed stuff. PARAMETERS
o $options - As of 5.3.6, this parameter is a bitmask for the following options: debug_print_backtrace(3) options +----------------------------+---------------------------------------------------+ |DEBUG_BACKTRACE_IGNORE_ARGS | | | | | | | Whether or not to omit the "args" index, and | | | thus all the function/method arguments, to save | | | memory. | | | | +----------------------------+---------------------------------------------------+ o $limit - As of 5.4.0, this parameter can be used to limit the number of stack frames printed. By default ($limit= 0) it prints all stack frames. RETURN VALUES
No value is returned. CHANGELOG
+--------+-----------------------------------------+ |Version | | | | | | | Description | | | | +--------+-----------------------------------------+ | 5.4.0 | | | | | | | Added the optional parameter $limit. | | | | | 5.3.6 | | | | | | | Added the optional parameter $options. | | | | +--------+-----------------------------------------+ EXAMPLES
Example #1 debug_print_backtrace(3) example <?php // include.php file function a() { b(); } function b() { c(); } function c(){ debug_print_backtrace(); } a(); ?> <?php // test.php file // this is the file you should run include 'include.php'; ?> The above example will output something similar to: #0 c() called at [/tmp/include.php:10] #1 b() called at [/tmp/include.php:6] #2 a() called at [/tmp/include.php:17] #3 include(/tmp/include.php) called at [/tmp/test.php:3] SEE ALSO
debug_backtrace(3). PHP Documentation Group DEBUG_PRINT_BACKTRACE(3)
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