Is it possible to use preg_match to require a special character in a password?

[pcghost]

Am I using the wrong function? I need to require the use of >= 1 number, >= 1 letter and >= 1 special character.

I figured out how to limit acceptable entries to numbers,letters, and specific specials, but how to require their use?

preg_match("/^{([[:alnum:]|!@#\$\%^\&*()-_\=+])+$/i",} $newpass)

😕

[Weedpacket]

You could do it in three separate matches, one for each category. That's probably the simplest method.

Otherwise you've got to take into account the six alternatives for ordering those, and of course you'd also need to sprinkle in .* all over the place to take into account the characters in between.

I guess you could also do it with three forward assertions using (?=) (only match the start of the string if there is a letter somewhere after, if there is a digit somewhere after it, and if there is a special character somewhere after it); that would be simpler than the second suggestion above, but I suspect it wouldn't be a useful amount faster than the first.

One last thing; you've gone a bit overboard with your escaping: - and $ are the only characters that need it.

Okay; tried all three and the first is easily the slowest. The fastest is the third.

/^(?=.*[a-z])(?=.*\d)(?=.*[@!#&_])/i

[pcghost]

Thanks for the tip weedpacket. The other problem I am having is in my alpha check. If I pass "a" to it it passes, but if I pass "a1" to it, it fails. Is there a switch to make it check all characters in the string for the presence of alpha characters?

Here is how it is currently written:

if(preg_match("/^{([[:alpha:]])+$/i",} $newpass)) {

[Weedpacket]

Originally posted by pcghost
Thanks for the tip weedpacket. The other problem I am having is in my alpha check. If I pass "a" to it it passes, but if I pass "a1" to it, it fails. Is there a switch to make it check all characters in the string for the presence of alpha characters?

Here is how it is currently written:

if(preg_match("/^{([[:alpha:]])+$/i",} $newpass)) {

It's failing because you're saying that every character has to be alphabetical (from the start of the string, match one or more alphabetical charaters, right up to the end of the string). If you just want to see if there is at least one alphabetical character somewhere in the string, drop the line-ending anchors ^ and $, and you can drop the + as well (because as soon as you find one you don't need to look for any more).

[pcghost]

That did it. You rule Weedpacket. Thanks for making regular expressions make sense to me. That script has been plaguing me for days...

🙂 🙂 🙂 🙂