How do I best pass arguments to a Perl one-liner?

Question

I have a file, someFile, like this:

$cat someFile hdisk1 active hdisk2 active 

I use this shell script to check:

$cat a.sh #!/usr/bin/ksh for d in 1 2 do     grep -q "hdisk$d" someFile && echo "$d : ok" done 

I am trying to convert it to Perl:

$cat b.sh #!/usr/bin/ksh export d for d in 1 2 do     cat someFile | perl -lane 'BEGIN{$d=$ENV{'d'};} print "$d: OK" if /hdisk$d\s+/' done 

I export the variable d in the shell script and get the value using %ENV in Perl. Is there a better way of passing this value to the Perl one-liner?

Answer 1

You can enable rudimentary command line argument with the "s" switch. A variable gets defined for each argument starting with a dash. The -- tells where your command line arguments start.

for d in 1 2 ; do    cat someFile | perl -slane ' print "$someParameter: OK" if /hdisk$someParameter\s+/' -- -someParameter=$d;  done 

See: perlrun