variable contains bash code example
Example 1: bash substring test
#!/bin/bash
STR='GNU/Linux is an operating system'
SUB='Linux'
if grep -q "$SUB" <<< "$STR"; then
echo "It's there"
fi
Example 2: bash substring test
#!/bin/bash
STR='GNU/Linux is an operating system'
SUB='Linux'
case $STR in
*"$SUB"*)
echo -n "It's there."
;;
esac