$x = `echo foo`;

##</code><code>##

$ cat t.pl
use strict;
use warnings;

print "Let's do a command:\n";
my $x = `echo foo`;
print "OK, command is done!\n\n";

print "Now let's see what we captured:\n<$x>\n";

##</code><code>##

$ perl t.pl
Let's do a command:
OK, command is done!

Now let's see what we captured:
<foo
>

##</code><code>##

print $x;

##</code><code>##

my @results = `command`;

##</code><code>##

my @foo = grep /foo/ @results;

##</code><code>##

if (0 == @foo) {
    print "The command didn't find 'foo'\n";
}
else {
    print "Found 'foo'!\n";
}

##</code><code>##

# Do the thing
my @results = `command`;

# Look for the stuff
my @foo = grep /foo/ @results;

# Did we find it?
if (0 == @foo) {
    print "The command didn't find 'foo'\n";
}
else {
    print "Found 'foo'!\n";
}