Menu
Is it possible to do a preg_match() on something that shouldn't be a match whilst still returning true?
For example, at the moment we have...
if (preg_match('#^Mozilla(.*)#', $agent)) {
We want to check if the Mozilla string is not in $agent, but still have preg_match return true.
We can't change it to:
if (!preg_match('#^Mozilla(.*)#', $agent)) {
974
preg_match in PHP function is used to search the string for a pattern and return a Boolean value. The search generally starts from the initial character of the string.
preg_match is case sensitive. A match. Add the letter "i" to the end of the pattern string to perform a case-insensitive match.
The preg_match() function returns whether a match was found in a string.
The preg_match() function searches string for pattern, returning true if pattern exists, and false otherwise. If the optional input parameter pattern_array is provided, then pattern_array will contain various sections of the subpatterns contained in the search pattern, if applicable.
What you want is a negative lookahead, and the syntax is:
if (preg_match('#^(?!Mozilla).#', $agent)) {
Actually, you can probably get away with just #^(?!Mozilla)# for this. I don't know how PHP will feel about a pattern that's nothing but zero-width tokens, but I've tested it in JavaScript and it works fine.
If you want to make sure Mozilla doesn't appear anywhere in the string, you could use this...
if (preg_match('#^((?!Mozilla).)*$#', $agent)) {
...but only if you can't use this!
if (strpos($agent, 'Mozilla') !== false) {
If you love us? You can donate to us via Paypal or buy me a coffee so we can maintain and grow! Thank you!
Donate Us With
