Filter::sh(3pm)

✨ NAME ✨

Filter::sh — a lil sh source filter that rewrites your Perl before Perl ever sees it 💅

(it lives in the User Contributed Perl Documentation section of the manual, bestie — page Filter::sh(3pm))

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🌸 SYNOPSIS 🌸

use Filter::sh 'command' ;

That's it. That's the whole vibe. 🎀

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🦋 DESCRIPTION 🦋

okay so here's the tea ☕ — this filter takes your current source file and pipes it straight through the program that your command parameter names, running it via the Bourne shell. So like. Your Perl gets a glow-up from a shell command before it's even compiled. iconic behavior honestly ✨

Now, important thing — like every single source filter ever — its scope is limited to the current source file only. No sneaky spreading to other files. Every file you want the filter to touch needs its own

use Filter::sh 'command' ;

sitting near the top. no exceptions, no shortcuts, fr fr 🙈

Here's an example script that uses the filter:

use Filter::sh 'tr XYZ PQR' ;
$a = 1 ;
print "XYZ a = $a\n" ;

and here's what it spits out 👇

PQR = 1

see how tr XYZ PQR just swapped those letters out? ate and left no crumbs 🍓

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💀 WARNING 💀

bestie please be careful with this one. 😭

You should be very careful when using this filter. Because of the way the filter is implemented, it is possible to end up with a deadlock. That's not a vibe. That's the opposite of a vibe. 💀

And be especially careful when you're stacking multiple instances of the filter inside a single source file. Stack 'em and you might just lock everything up. the math is not mathing in your favor, ngl 🙈

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👑 AUTHOR 👑

Paul Marquess wrote this one. legend behavior, no cap. 🫶

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⭐ DATE ⭐

11th December 1995. yes bestie, a vintage. it was slaying before most of us could walk 💅✨

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k bye, and remember — this page came to you from perl v5.42.3, dated 2026-08-19, filed under Filter::sh(3pm) in the User Contributed Perl Documentation. mwah 🎀💖