Can't seem to get the regex pattern right

Question

I need to check a string for a certain string, I want to use regex for this, but the more I keep trying, the more it confuses (and frustrates) me; I can't seem to get it right.

I need the expression to return true when the string contains something like this: [[module:instance]], but it needs to meet the following conditions:

• Always open with 2 brackets [[
• After the two brackets the string can contain everything except for :, and has no limit to it's length
• After the string 1 : character must be present
• After the : again a string that can contain everything except a :, and has no limit to it's length
• Always close with 2 brackets ]]

Any help, tips, good tutorials, anything would be greatly appreciated!

Thanks in advance!

Answer 1

Try this:

preg_match('/\[\[[^:]+?:[^:]+?]]/', $str, $match)

An explanation:

• \[\[ matches the literal [[
• [^:]+? matches anything but : (non-greedy)
• : matches the literal :
• [^:]+? matches anything but : (non-greedy)
• ]] matches the literal ]].