TSORT(1)

✨ TSORT(1) — tsort (topological sort), bestie edition ✨

hey bestie! welcome to the TSORT(1) page from the User Contributed Perl Documentation — aka the tsort manual, and yes we’re gonna make topological sorting make sense. 💖

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🌸 NAME 🌸

tsort — topological sort. That’s the name, that’s the job, and it’s iconic. periodt. 💅

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🦋 SYNOPSIS 🦋

the whole invocation is literally just:

tsort [filename]

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💖 DESCRIPTION 💖

OKAY so tsort does a topological sort of input pairs. It takes input from the standard input if you don’t provide a filename argument — no cap, stdin is the default bestie. 🫶

For a more complete description, see the tsort(1) man page. For an explanation of the algorithm, see the Work column in the October, 1998, issue of SunExpert, or the references given below. ✨

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💅 OPTIONS AND ARGUMENTS 💅

• [-b|-d] — breadth-first or depth-first traversal; depth-first is the default. Choose your traversal vibe wisely. 🌈
• filename — optional input file. Input format is pairs of white-space-separated fields. Each field is the name of a node. Output is the topologically sorted list of nodes. 🎀

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🎀 AUTHOR 🎀

Jeffrey S. Haemer. Give him his flowers. 💐

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🌈 SEE ALSO 🌈

• tsort(1)
• tcsh(1)
• tchrist(1)

Algorithm stolen from Jon Bentley (More Programming Pearls, pp. 20-23), who, in turn, stole it from Don Knuth (Art of Computer Programming, volume 1: Fundamental Algorithms, Section 2.2.3). the algorithm lore is real. 📚✨

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💖 xoxo, your Perl bestie — this page is from perl v5.42.2, dated 2026-02-15. slay! 💖