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Asked: 2021-01-09 05:26:51 +0800 CST

How to make grep grab the first hit instead of the last

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Let's say I have the following string:

hello hi this test is test a test greeting test hello hello

If I do grep -o "hi.*test", I will get:

hi this test is test a test greeting test

It greps everything between the first hit of 'hi' and the last hit of 'test'. How can I make it so that it stops grepping at the first hit. AKA:

If I do grep -o "hi.*test" (ofcourse with an extra flag or a different command), I will get:

hi this test

Instead of:

hi this test is test a test greeting test

It needs to stop at the first 'test', not the last.

How do I do that? Thanks!

EDIT to clarify: If I have the following:

hello this is a test hello this is a test

And I do grep "hello.*test", I will get the complete string. But I want:

hello this is a test
hello this is a test

AKA it found the string two times AKA it searched for "hello this is a test" and found it twice

grep

1 Answers

  1. You can do this using PCRE mode (grep -P) by using the Perl non-greedy modifier ?:

    $ printf '%s\n' 'hello this is a test hello this is a test' | grep -Po 'hello.*?test'
hello this is a test
hello this is a test
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