How to invoke shell in perl and how to capture the error if any?

http://www.perlmonks.org/?node_id=57193

system("wc -l");
Will call the given command and return the return value of that command. This is usually not what you want, because most of the times wc -l will mean that you want to get the number of lines back from that call and not if that call was successful or not.


$nol = `wc -l`
The backticks call the command and return it's output into the variable (here $nol. In this case this will be what you want.
Another way of doing this is to use

$nol = qx/wc -l/;
(mnemonic: qx quote execute). I think is just the same as the backquotes (at least I don't know any difference)

Of course there are other ways (exec,fork) that behave different with respect to processes, but I don't know much about this.

And use $? to check the error code of backticks of system().