Grep: Use colour for one of multiple expressions

Question

Is it possible to have grep search for multiple expressions, but only colour a specific one of them?

Example of what I'm after:

cat file | grep -e foo --colour -e bar

Output (where bold represents coloured):

foo baz

bar baz

qux foo

foo bar

Hauke Laging · Accepted Answer · 2017-11-17 15:58:03Z

1

PCRE can be abused so that there is a match but nothing matched that would be highlighted:

grep -P 'foo.*\K$|bar' input

answered Nov 17, 2017 at 15:58

Hauke Laging

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chraffx · Accepted Answer · 2017-11-17 09:42:35Z

0

A solution (though not particularly elegant) is to use multiple grep queries.

cat file | grep -e foo -e bar | grep -9999 --colour -e bar

Note: The -9999 flag is a hack to get grep to output a lot of lines from stdin. It is possible to increase the value if it is required.

answered Nov 17, 2017 at 9:42

chraffx

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2 Answers 2