Question

I’m trying to capture standard output of a command to a file-like object in Perl.

I essentially need to do the following:

1. Execute an OS command, capturing standard output.
2. Run a regular expression on each line of the file and pull output into an array.
3. Call another OS command for each item in the array of lines of output from the first command.

How can I do step one? I’d like to execute a command and get its standard out in a filelike object so as to be able to read it line by line.

Answer 1

The first part is easy:

use autodie qw(:all);
open my $input, '-|', 'os-command', @args;

Clearly, the remainder is not much harder:

while (<$input>)
{
     next unless m/your regex/;
     system 'other-command', $_;
}

Automatic error checking for the open and system calls is provided through autodie.