Bash checking if string does not contain other string
Bash allow u to use =~ to test if the substring is contained. Ergo, the use of negate will allow to test the opposite.
fullstring="123asdf123"
substringA=asdf
substringB=gdsaf
# test for contains asdf, gdsaf and for NOT CONTAINS gdsaf
[[ $fullstring =~ $substring ]] && echo "found substring $substring in $fullstring"
[[ $fullstring =~ $substringB ]] && echo "found substring $substringB in $fullstring" || echo "failed to find"
[[ ! $fullstring =~ $substringB ]] && echo "did not find substring $substringB in $fullstring"
Use !=
.
if [[ ${testmystring} != *"c0"* ]];then
# testmystring does not contain c0
fi
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for more information.