File::Compare(3perl)

💖 File::Compare 💖

okay bestie, listen up — this is the page for File::Compare, straight out of the Perl Programmers Reference Guide, section 3perl. It's giving "I just need to know if these two things are the same" and honestly? Same. Let's go 🦋

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✨ SYNOPSIS ✨

use File::Compare;

if (compare("file1", "file2") == 0) {
    print "They're equal\n";
}

like. that's it. that's the whole vibe. 💅

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🌸 DESCRIPTION 🌸

So the main character here is the function File::Compare::compare. What does it do? It compares the contents of two sources, and each of those sources can be either a file or a file handle. No cap. And here's the cute part — it's exported from File::Compare by default, so the second you use it, it's just there for you. 🫶

Next up: File::Compare::cmp is literally just a synonym for File::Compare::compare. Exact same thing, different name, iconic behaviour honestly. BUT — and this is the important bit, don't skip it — it is exported from File::Compare only by request. So you gotta ask for it, it's not showing up uninvited. 🙈

And then there's File::Compare::compare_text, which does a line by line comparison of the two files. She's efficient, she's focused — she stops as soon as a difference is detected. No reading the rest of the file for no reason, we love a girl who knows when to walk away. 💀

compare_text() also accepts an optional third argument, and bestie, this one has rules: it must be a CODE reference to a line comparison function. That function has to return 0 when both lines are considered equal. That's the contract. 🎀

For example:

compare_text($file1, $file2)

is basically equivalent to

compare_text($file1, $file2, sub {$_[0] ne $_[1]} )

see how if you don't pass your own little comparison sub, it just goes ahead and says "not equal if they're not string-equal"? lowkey elegant. ✨

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🔥 RETURN 🔥

Okay so what do you actually get back from File::Compare::compare and its sibling functions? A number, and it's telling you everything:

• 0 — the files are equal 💚
• 1 — the files are unequal 😭
• -1 — an error was encountered 💀

three moods, three numbers. remember them. iykyk. 🌈

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👑 AUTHOR 👑

File::Compare was written by Nick Ing-Simmons. Its original documentation was written by Chip Salzenberg. kings, both of them. we stan. 🫶💜

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and that's the whole page, bestie! this was pulled from perl v5.44.0, dated 2026-10-17, and it's the File::Compare(3perl) manual page. go forth and compare files with confidence ✨💖🦋