Question

thank you for reading.

For a shell command to wget, something like this works:

wget -q -O - http://www.myweb.com | grep -oe '\w*.\w*@\w*.\w*.\w\+' | sort -u

However, when I try to insert that command inside the Perl program, then I get a syntax error referring to “backslashes found where operator expected, bareword found where operator expected”. So I replaced the quotes that surround the regex by this {} but, what that does is just like commenting it out, it does not bring the error, but it is as if the regex weren’t, so obviously the curly braces are a wrong attempt.

This is the code, it is inside a foreach:

foreach(@my_array) {

$browser->get($_);
# and here below is where the error comes
system ('wget -q -O -"$_" | grep -oe '\w*.\w*@.\w*.\w\+' | sort -u');

If I replace the single quotes wrapping the regex by {}, then wget does get the URLs but the grep command does not act.

So that is the issue, how to resolve the quotes annoying the syntax

Answer 1

You want this:

system ("wget -q -O -\"$_\" | grep -oe '\\w*.\\w*@.\\w*.\\w\\+' | sort -u");

You can include what you like within double quotes, only you have to escape certain characters.

Incidentally, Perl’s qq() operator might interest you. You can look it up.