Does Bash support non-greedy regular expressions? Regular expressions (regex) are similar to Glob Patterns, but they can only be used for pattern matching, not for filename matching. 3866. grep , expr , sed and awk are some of them.Bash also have =~ operator which is named as RE-match operator.In this tutorial we will look =~ operator and use cases.More information about regex command cna be found in the following tutorials. I know that BASH =~ regex can be system-specific, based on the libs available -- in this case, this is primarily CentOS 6.x (some OSX Mavericks with Macports, but not needed) Thanks! 4521. A qualifier identifies what to match and a quantifier tells how often to match the qualifier. Bash regex test not working. I'm sure this is simple, I just can't get my brain around it. Regular Expression to Given a list of strings (words or other characters), only return the strings that do not match. [^chars] is merely a commonly-supported extension. Regular expressions are great at matching. Simple Regex match not working. 2. Related. 2377. The most significant difference between globs and Regular Expressions is that a valid Regular Expressions requires a qualifier as well as a quantifier. It's easy to formulate a regex using what you want to match. 3. I'd like to be able to match based on whether it has one or more of those strings -- or possibly all. Bash regex matching not working in 4.1. One easy way to exclude text from a match is negative lookbehind: w+b(?