Check if a variable is present in an array using shell script

Last updated on October 25th, 2014 at 09:40 am

An array is like a list of elements, you can refer to specific elements in an array with indices. For instance myarray[i] refers to the i th element in an array named myarray. Here i am using korn shell.

We can use the below shell script in order to search for an element and return a unique output if it is present in the array or not.

This script simply helps you to check whether a variable is present inside an array.

First initialize the array element using set command.

set -A myarray data1 data2 data3 data4

Now create a script that will search whether a variable is present in an array or not.

if [[ " ${myarray[*]} " == *" $1 "* ]]; then
check_val=$1
echo "Found Element "$check_val
else
check_val=$1
echo "Did Not Find Element Named "$check_val
fi

$1 represent the first argument passed to the script.

Please find the complete script below.

set -A myarray data1 data2 data3 data4
if [[ " ${myarray[*]} " == *" $1 "* ]]; then
check_val=$1
echo "Found Element "$check_val
else
check_val=$1
echo "Did Not Find Element Named "$check_val
fi

Save the script as check.sh

Usage

./check.sh data1

The output of the above command will be

Found Element data1

You can also add this shell script as a function and call it at any time you need. All you have to do is just enclose the script inside

function SOME_FUNCTION_NAME
{
set -A myarray data1 data2 data3 data4
if [[ " ${myarray[*]} " == *" $1 "* ]]; then
check_val=$1
echo "Found Element "$check_val
else
check_val=$1
echo "Did Not Find Element Named "$check_val
fi
}
#Call the function 
SOME_FUNCTION_NAME "CheckThisElement"

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