How do you use sed from Perl?

Question

I know how to use sed with grep, but within Perl the below fails. How can one get sed to work within a Perl program?

chomp (my @lineNumbers=`grep -n "textToFind" $fileToProcess | sed -n 's/^\([0-9]*\)[:].*/\1/p'`)

Answer 1

Use power Luke:

$ echo -e "a\nb\na"|perl -lne'/a/&&print$.'
1
3

Thus when you want same think as this slow and overcomplicated grep and sed combination you can do it far simpler and faster in perl itself:

my @linenumbers;
open my $fh, '<', $fileToProcess or die "Can't open $fileToProcess: $!";
while (<$fh>)
{
   /textToFind/ and push @lineNumbers, $.;
}
close $fh;

Or with same memory culprits as the original solution

my @linenumbers = do {
    open my $fh, '<', $fileToProcess or die "Can't open $fileToProcess: $!";
    my $i;
    map { ( ++$i ) x /textToFind/ } <$fh>
};