How can I match an exact word within a string that is surrounded by whitespaces?-CodePudding

I am trying to match a specific command using regex based on a set of allowed commands.

This is the outcome I want to achieve:

foo --happy-cat run meow # valid command
foo --happy-cat test meow # valid command
foo --happy-cat run-away woof # invalid command

This is what I have tried to do

case $* in
  (*run* | *test* | *build*) echo yes ;;
  *) echo no ;;
esac

What's not working My match falsely matches run-away as a valid command. I only want to match run, test or build surrounded by whitespace

CodePudding user response：

You will have to match spaces around given words like this:

case "$*" in
  *" run "*|*" test "*|*" build "*) echo yes ;;
  *) echo no ;;
esac

Also this is called glob matching not regular expressions.

Above script will match " run " and print yes, however for run-away it will not match first set of globs and will print no.

CodePudding user response：

To add to anubhava's answer, if you wanted to use actual regex you could do this:

s='foo --happy-cat run-away woof'  # test string
regex='\s ((run)|(test)|(build))\s '

if [[ $s =~ $regex ]]
then
  echo "yes"
else
  echo "no"
fi

This has the advantage of matching whitespace that isn't just space, but also tabs.