CODEWITHSUNDEEP
regexbashgrep
rooni
rooni

Reputation: 1090

regular expression in bash with grep

I am trying to print strings that contain any number of '=' signs in it. For that i am using the following command in bash

cat myfile | grep '^.*=+.*$'

I am writing ^ and $ for start and end of string

.* for any numnber of any character.

=+ for one or more equal(=) character.

But it doesn't show any output when executed.

But if i do simply:

cat myfile | grep '='

I get the desired output Why is this so?

What am i missing here ?

Upvotes: 0

Views: 52

Answers (1)

user11750591
user11750591

Reputation:

The regex you're using isn't a basic posix regex. For example it tries to match the + literally.

You should try using

cat myfile | grep -E '^.*=+.*$'

the -E is for extended regular expressions.

Wikipedia has a nice comparison of posix basic and extended regular expressions where you also can see that + is only a meta character in the extended version: https://en.wikipedia.org/wiki/Regular_expression#POSIX_extended

Upvotes: 1

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