CODEWITHSUNDEEP
regexbash
user34345352
user34345352

Reputation: 91

Matching regex in bash

I'm trying to match the parameters of a bash script with a regex

mykill.bash [-l] [-s SIGNO] pattern1 pattern2

I'm using this expression:

regex = ^(-l)?(\s-s\s[0-9]+)?(\s[a-zA-Z0-9]+){1,2}$ <br>
if [[ $@ =~ $regex ]]; then echo 'cool'

for example ./mykill.bash -l -s 33 abc gives $@='-l -s 33 abc' which passes the debuggex.com tests (see image but it doesn't work in my script

enter link description here

Upvotes: 4

Views: 293

Answers (3)

Oskar Hane
Oskar Hane

Reputation: 1882

Some versions of bash does not catch \s the way we are used to in other languages/flavors. One version it does not catch \s is on my MacBook Air with GNU bash, version 3.2.48(1)-release-(x86_64-apple-darwin12).

And you should not have spaces around = when assigning a value to a variable.

As Ken-Y-N said in the comments to your post, your pattern has some problems as well, I fixed it in my code below.

This should do it if \s is the problem:

#!/bin/bash
re='^(-l\ )?(-s\ [0-9]+\ )?([a-zA-Z0-9]+)(\ [a-zA-Z0-9]+)?$'
if [[ $@ =~ $re ]]; then
    echo 'cool'
fi

There's no need to escape the spaces like i did, but I find it easier to read this way.

Upvotes: 3

SzG
SzG

Reputation: 12629

You have bash problems, not a regex problem.

When assigning variables in bash: no space around the = please. Then if you want to preserve backslashes and whitespace in the regex, use single quotes around it, otherwise bash eats them for breakfast. You don't need to quote cool. And close the if with a fi.

regex='^(-l)?(\s-s\s[0-9]+)?(\s[a-zA-Z0-9]+){1,2}$ <br>'
if [[ $@ =~ $regex ]]; then echo cool; fi

Or use the simpler form of the conditional:

[[ $@ =~ $regex ]] && echo cool

Upvotes: 4

user1502952
user1502952

Reputation: 1420

As per your input, this will match

if [[ $@ =~ -l\ -s\ [0-9]+\ [a-zA-Z]+ ]]
then 
      echo 'cool'
else
      echo 'check again' 
fi

Upvotes: 0

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