http://www.perlmonks.org?node_id=1004248


in reply to One Liner, print multiple regex matches

In both those cases, you've got syntax errors. You could modify the second one to use two look-aheads (see Looking ahead and looking behind in perlretut) to grab the fields:

perl -nle ' print "$1$2" if /(?=name=(\w+))(?=age=(\d+))/' filename

Note how your omission of quotes or a comma from your second case means that $1 is being treated at a filehandle.

Your third version fails because you are only allowed one if per statement (see Compound Statements). You could make this work using && and || like:

perl -nle ' /name=(\w+)/ && print($1) || /age=(\d+)/ && print($1) ' filename

or, use two different statements to make it even easier:

perl -nle 'print $1 if /name=(\w+)/; print $1 if /age=(\d+)/' filename

Note that you are using two different regular expressions, so each one would set the $1 buffer if it matches.

As a last comment, assuming you are running a reasonably recent version of perl, your output might be easier to deal with if you use -E in place of -e and swap your prints to says (see perlrun).

Oh, and please wrap input data in <code> tags, as white space is mangled on display if you don't.


#11929 First ask yourself `How would I do this without a computer?' Then have the computer do it the same way.