search for a variable in a string in bash

Question

I have a string given below:

string1 = "Hello there, my name is Jack.
Hello there, my name is Jack.
Hello there, my name is Jack."

I'm taking the following input from the string:

read string2

I want to check whether the string2(which is a variable) is present in string1.

I tried running the below command:

output=$(echo $string1 | grep -o "$string2")
echo $output

eg: Let string2="name" The output is empty when I'm running this command. Can someone tell me where am I going wrong?

I'm not sure if this is the cause of the problem but you should not put a whitespace before and after the `=` character when assigning `string1`. — tshiono, Aug 17 '22 at 07:16

score 1 · Accepted Answer · answered Aug 17 '22 at 07:20

1

#!/bin/bash

string1="Hello there, my name is Jack"
string2="name"

if [[ $string1 == *"$string2"* ]]; then
    echo "$string2 found"
else
    echo "$string2 not found"
fi

answered Aug 17 '22 at 07:20

David Ranieri

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score 1 · Answer 2 · answered Aug 17 '22 at 07:34

1

Alternate method with POSIX-shell grammar:

string1='Hello there, my name is Jack'
string2='name'

case "$string1" in
  *"$string2"*) printf '%s found\n' "$string2";;
  *) printf '%s not found\n' "$string2";;
esac

answered Aug 17 '22 at 07:34

Léa Gris

17,497
4
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search for a variable in a string in bash

2 Answers2