my $answer= log_in_box_and_do_something();
open(F,'<',$filename) or die "Could not open $filename\n";
my $compare= <F>;
if ($answer eq $compare) {
#both are equal
}
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This is a very basic method, the slightest difference will throw it off, even if it is only a space character. If you want more, you could use a command line utility like diff (on unix/linux) or extract the important elements with some regexes and compare those to the file

Thanks for your reply. I am wanting to verify that what is returned from various commands on the box does not change when the code changes.. i.e. I want to make sure the same response to the commands are obtained when I install new code .... it is part of some automated regression tests I am scripting.

Oh, in that case just compare the outputs with the cmp program if the outputs are written to files (eg. system("diff", "-s", "--", $filename1, $filename2) returns true if the files are different).

If you're sure you want the outputs in arrays, compare them with like join("", @output1) eq join("", @output2) if the lines in the arrays still have the trailing newlines or pack("(J/a)*", @output1) eq pack("(J/a)*", @output2) if you're not sure what the delimiters are or @output1 == @output2 and !grep { $output1[$_] ne $output2[$_] } 0 .. @output1 - 1 if you don't want to waste memory.

Could you be more precise? Do you want to compare two files by finding lines that are in one of them but not in the other? Or do you want a line-by-line diff where order of lines matters as well? If the latter, you can try calling the external diff program eg. like in Htmlify code with differences.

use strict;
use warnings;

use Digest::SHA;

open my $in_1, '/tmp/f1.txt';
open my $in_2, '/tmp/f2.txt';

my $hash1 = Digest::SHA::sha1_hex(
        do { local $/; <$in_1> }
);

my $hash2 = Digest::SHA::sha1_hex(
        do { local $/; <$in_2> }
);

die "The files are NOT the same\n" unless $hash1 eq $hash2;
print "The file contents are identical\n";
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md5sum file1 file2 file3 etc
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