Stderr(3)

✨ Stderr — Tk::Stderr ✨

okay bestie, welcome to Tk::Stderr, straight out of the User Contributed Perl Documentation corner of the manual universe (yes, it lives on the Stderr(3) page, iconic 💅). This is the module that catches your program's standard error output and shows it off in its own separate little window. slay.

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🌸 NAME 🌸

Tk::Stderr — capture standard error output, display in separate window 🫶

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🎀 SYNOPSIS 🎀

use Tk::Stderr;

$mw = MainWindow->new->InitStderr;
print STDERR 'stuff';   ## goes to standard error window
warn 'eek!';            ## likewise

like… that's it. that's the whole vibe. you InitStderr once and suddenly every print STDERR and every warn is living its main character era in its own window 🦋

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💖 DESCRIPTION 💖

so basically, this module captures the standard error of a program and redirects it into a read-only text widget. and the way that it's shy?? it literally does not appear until it's actually necessary. no cap. 🙈

and when it does show up, the user can close it — and it'll pop back up again the moment there's more output. it's giving "can't stay away" energy 💀

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👑 METHODS 👑

okay so plot twist: these are actually added to the MainWindow class. not a regular method moment. keep that in mind, bestie.

• $mw->InitStderr; — the first time this method is called, it does these things:
  • Creates a MainWindow holding a read-only scrollable text widget, and withdraws this window until it's actually needed. ✨
  • Ties STDERR to a special handle that adds the output to this text widget.
  • Installs a $SIG{__WARN__} handler that redirects the output from warn to this window as well (by printing it to STDERR).

On the remaining calls, it:

• Increments a reference count of "other" MainWindows.
• Installs an OnDestroy handler that decrements this reference count, so that it can detect when it's the only MainWindow left and destroy itself. 💀

• $errwin = $mw->StderrWindow; — returns a reference to the main window holding the text. You can use this to configure the window itself or the widgets it contains. The only advertised subwidget is 'text', which is the scrolled read-only text widget. 🎀
• $old = $mw->RedirectStderr($boolean); — enables or disables the redirection of standard error to the text window. Set $boolean to true to enable redirection, false to disable it. Returns the previous value of the enabled flag. 🌈

heads up bestie: if InitStderr has never been called, this routine will call it if $boolean is true. so it's lowkey doing the setup for you 👑

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🦋 AUTHOR 🦋

Kevin Michael Vail <kevin@vaildc.net> 💜

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and that's the whole page fr fr — brought to you by perl v5.42.0, dated 2025-07-25, on the Stderr(3) page. go forth and capture that stderr, bestie, you're gonna ate 💅✨