How do I match a square bracket literal using RegEx?

Question

What\'s the regex to match a square bracket? I\'m using \\\\] in a pattern in eregi_replace, but it doesn\'t seem to be able to find a ]..

Answer 1

There are two ways of doing this:

/ [\]] /x;

/  \]  /x;

While you may consider the latter as the better option, and indeed I would consider using it in simpler regexps. I would consider the former, the better option for larger regexps. Consider the following:

/ (\w*) (  [\d\]] ) /x;

/ (\w*) ( \d | \] ) /x;

In this example, the former is my preferred solution. It does a better job of combining the separate entities, which may each match at the given location. It may also have some speed benefits, depending on implementation.

Note: This is in Perl syntax, partly to ensure proper highlighting.
In PHP you may need to double up on the back-slashes. "[\\]]" and "\\]"