Execute a system command
run "ls" or die $!; # output to stdout
my @ls = qx/ls/; # output to variable
my $cmd = 'ls';
@ls = qqx/$cmd/; # same thing with interpolation
run "ls" or die $!; # output to stdout
my @ls = qx/ls/; # output to variable
my $cmd = 'ls';
@ls = qqx/$cmd/; # same thing with interpolation