BWISH(1)

📦
version 7.44.0 · 2 versions
, in nixpkgs unstable

💅 bwish(1) — the BRL-CAD Tcl/Tk windowing shell 💅

okay so welcome to bwish, bestie — the manual page for it, anyway. This is section 1 of the BRL-CAD manual, and honestly? She's kind of the main character of BRL-CAD's graphical scripting world, iykyk. Let's get into it 🎀

✨ NAME ✨

bwish — BRL-CAD's Tcl/Tk windowing shell. that's it, that's the vibe 💖

🌸 SYNOPSIS 🌸

bwish [script [arg ...]]

Both script and arg are optional — the brackets said so, not me 🫶

🦋 DESCRIPTION 🦋

So bwish is a Tcl/Tk windowing shell, right? Think of it as the standard Tk wish(1) interpreter's cooler sibling — same energy, except this one comes preloaded with BRL-CAD's Tcl/Tk extensions: libtclcad, Itcl/Itk, and the associated BRL-CAD libraries. She's basically born ready ✨

She's also the graphical counterpart to btclsh(1), and she provides the scripting + GUI foundation that BRL-CAD tools like mged(1) and archer(1) are built on top of. So yeah, iconic behavior 💅

here's how the arguments work:

  • If the first argument does not begin with a -, bwish takes it as the name of a Tcl/Tk script to evaluate. She runs that script, then enters the event loop. 🏃‍♀️
  • Any remaining arg values get handed to the script through the Tcl global variables argv and argc, and argv0 is set to the script name. very generous of her 💜

And if no script is given (or the first argument begins with a -), she just runs interactively:

  • she reads commands from standard input, with emacs-style command-line editing and history — so like Ctrl+A, Ctrl+E, Ctrl+K, Ctrl+W, plus the arrow keys for history and cursor movement. your fingers already know these 🎀
  • on startup she evaluates the resource file ~/.bwishrc (or ~/.bwishrc.tcl on Windows) if it exists. cute little startup ritual 🌸
💀 important vibe check: bwish does not interpret any command-line options of its own. every flag is left for the executed script to handle via argv. so don't come for her about options, she literally has none, periodt.

🔥 EXAMPLES 🔥

Example 1. Run a Tk script with arguments

bwish make_dialog.tcl 800x600 model.g

This evaluates the Tcl/Tk script make_dialog.tcl with the BRL-CAD extensions already loaded, passing 800x600 and model.g to the script as argv. And because libtclcad is initialized, the script can open and query BRL-CAD geometry databases directly. no cap, straight to the geometry 😭👑

Example 2. Interactive geometry scripting

bwish
bwish> package require Tk
bwish> set db [go_open db file model.g]
bwish> button .quit -text Quit -command exit; pack .quit

Starts an interactive session, builds a little Tk control, and works with a BRL-CAD database through the bundled commands — all without writing a separate script file. the way that she just... does it all in the prompt 🧚✨

👑 SEE ALSO 👑

brlcad(1), btclsh(1), mged(1), archer(1)

go read those too, bestie, they're all part of the family 🫶

⭐ AUTHOR ⭐

BRL-CAD Team 💖

This software is Copyright (c) 1989-2026 by the United States Government as represented by U.S. Army Research Laboratory.

(yes, the dates are literally 1989-2026, copy them exactly, don't @ me 😌)

🍓 BUG REPORTS 🍓

Reports of bugs or problems should be submitted via electronic mail to devs@brlcad.org

like, please actually tell them, she wants to be her best self 🙈💜

and that's the page, bestie!! 💅✨ this whole thing comes to you from the BRL-CAD crew — the BWISH(1) page in the BRL-CAD manual set — mwah, go script something iconic 🎀🦋💖

📦 where this page comes from