CODEWITHSUNDEEP
linuxbashscripting
Hassen Fatima
Hassen Fatima

Reputation: 423

How to check if $1 contains special characters in bash script?

I want to check if $1 has any of the following special characters @#$%&*-=+

User will run the script like this:

testserver@matrix:~> scriptname somer@nd$m

script should detect if somer@nd$m has any special character! Thanks

Upvotes: 1

Views: 5790

Answers (2)

kojiro
kojiro

Reputation: 77137

In general, to determine if a variable contains a member of a set of characters, you can use Pattern Matching with a character set as described in the bash manual.

[[ $var = *[set]* ]]

In your case, the set composition is tricky. It contains "&" and "-", which have special meaning. The dash goes first, or the shell considers the character set a range. The ampersand just has to be escaped. So you have to do

[[ $var = *[-@#$%'&'*=+]* ]]

Upvotes: 4

iMobs
iMobs

Reputation: 81

If you're looking for just the existence of a special characters you can use

if egrep -q "[@#$%&*-=+]" <<< "$1"
then
    echo "Special Characters"
fi

Be aware though in your example that passing in somer@nd$m will try to find a variable named m unless you pass the argument in single quotes.

Upvotes: 0

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