MULTIDELTA(1)

📦
version 2006.08.03 · 3 versions
, in debian bookworm, debian trixie, ubuntu noble

💖 MULTIDELTA(1) 💖

okay bestie, welcome to multidelta — it's a heuristic minimizer of interesting files. yes that's the actual vibe. it's giving detective energy, and i'm obsessed. 🕵️♀️✨

✨ SYNOPSIS ✨

multidelta [options] test-script initial-file [initial-file...]

🦋 DESCRIPTION 🦋

so like, multidelta (and its whole Delta family) helps you minimize "interesting" files — where "interesting" means a test decides they're interesting. the classic scenario, no cap: you've got a HUGE input that makes your program do a bug 😭 and you want to isolate the tiny little failure-inducing substring causing it. that's the whole point. that's the main character moment.

you supply multidelta with:

  • a test shell script</> which decides if the input files are "interesting" (test-script), and
  • an initial set of input files.

okay so here's the tea about how that script gets run ☕:

  • When the script is run with a source file as an argument, it should do any single-file integrity checks on that file. Then, it should proceed to check the entire build, on the assumption that all other files have already passed their integrity checks.
  • When the script is run with no arguments, it should check integrity of all files and then check the build.

and so that you don't have to hardcode the file list in your script (ugh, imagine 🙈), the environment variable multidelta_all_files is always set to a space-separated list of the filenames — no matter how the script is run. every single time. iconic behaviour honestly.

💅 OPTIONS 💅

  • -level=n — when topformflatten(1)ing, flatten to level n. the default is 0. so if you don't say anything, you get level 0, periodt.
  • -u — undo the last invocation, by copying the *.bak files onto the original copies. it's giving ctrl+z for your whole minimisation run 🫶
  • -cpp — before flattening, run the source through the cpp(1) preprocessor. fancy 💅

🌈 SEE ALSO 🌈

Delta Debugging project <http://www.st.cs.uni-sb.de/dd/> — go look, it's lowkey iconic 🔥

and that's the whole page, bestie!! 💖 this was Delta 2006.08.03, dated 2022-05-27, and it ate. mwah. 🎀✨🦋

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