Match regex in ksh

Question

I am looking to do something like this in KSH:

if (( $var = (foo|bar)[0-9]*$ )); then
    print "variable matched regex"
fi

Is it possible at all?

For the record I'm using Ksh Version M-11/16/88i on a Solaris 10 machine.

Answer 1

Ksh has regular expressions, but not in the usual syntax (not in the version in Solaris 10).

if [[ $var = *@(foo|bar)*([0-9]) ]]; then …

In the manual, look under “conditional expressions” for what's inside the brackets and under “file name generation” for the pattern syntax.

Answer 2

Using case with glob patterns might work for you. The composite pattern *(pattern-list) means "Matches zero or more occurrences of the given patterns" and @(pattern-list) means "Matches exactly one of the given patterns."

matcher() {
  typeset var="$1"
  case "$var" in
    *@(foo|bar)*([0-9])) print "$var matched" ;;
    *) print "$var did not match" ;;
  esac
}

for var in foo bar baz foo123 abc_foo132 abc_foo123z bar1 1bar1 1bar1a; do 
  matcher "$var"
done

Outputs:

foo matched
bar matched
baz did not match
foo123 matched
abc_foo132 matched
abc_foo123z did not match
bar1 matched
1bar1 matched
1bar1a did not match

Answer 3

Why not use egrep(1)? Gives you all a regex user could wish for:

 if echo "$var" | egrep -s '(foo|bar)[0-9]*$'    # -s means "silent"
  then
    ...

Additional note for Solaris: With Solaris you may want to check the manpage for egrep - there is annother egrep version that is located at /usr/xpg4/bin/egrep that supports some more options and differs in functionality when it comes to advanced regex stuff.

Answer 4

I did something like this, using sed. I don't know how good it is, but at least it worked ^^

if [ -z "$(echo "$var" | sed -e 's/(foo|bar)[0-9]*$//')" ]; then
    print "variable matched regex"
fi