Negative matching using grep (match lines that do not contain foo)

How do I match all lines not matching a particular pattern using grep? I tried this: grep ''[^foo]''

2025 Jul 07

matchFeatures

This MATLAB function returns indices of the matching features in the two input feature sets.

2024 Jun 20

OR condition in Regex

For example, ab|de would match either side of the expression. However, for something like your case you might want to use the ? quantifier, which will match the previous

2024 Jan 08

Regular expression to stop at first match

to capture a match between start and the first occurrence of end. Notice how the subexpression with nested parentheses spells out a number of alternatives which between them allow e only

2025 Sep 30

Regular expression to match string starting with a specific word

How do I create a regular expression to match a word at the beginning of a string? We are looking to match stop at the beginning of a string and anything can follow it. For

2024 May 07

XSL: Meaning of `match="/"` for `xsl:template`

The value of the match attribute of the <xsl:template> instruction must be a match pattern. Match patterns form a subset of the set of all possible XPath expressions. The first,

2025 Jul 31

regex

Is there a way in Python to access match groups without explicitly creating a match object (or another way to beautify the example below)? Here is an example to clarify my motivation for

2026 Feb 15

Differences between re.match, re.search, re.fullmatch

Answer (line anchors vs string anchors) What this tells me is that re.match and re.fullmatch don''t match line anchors ^ and $ respectively, but that they instead match string anchors A and Z

2024 Oct 13

python

From the docs on re.match: If zero or more characters at the beginning of string match the regular expression pattern. I just spent like 30 minutes trying to understand why I couldn''t match

2025 Nov 15

How to match, but not capture, part of a regex?

A variation of the expression by @Gumbo that makes use of K for resetting match positions to prevent the inclusion of number blocks in the match. Usable in PCRE regex flavours.

2024 Dec 27

View/Download How to match the solar container lithium battery pack [PDF]

PDF version includes complete article with source references. Suitable for printing and offline reading.