fstreverse(1)

💖 fstreverse(1) — User Commands 💖

okay bestie, welcome to fstreverse, a little icon living in the User Commands section of the manual 🎀 she does ONE thing and she does it flawlessly, and I'm obsessed with her.

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✨ NAME ✨

fstreverse — reverse the paths in an FST 🦋

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✨ SYNOPSIS ✨

fstreverse [OPTIONS] [in.fst [out.fst]]

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✨ DESCRIPTION ✨

Reverse the paths in an FST. That's it. That's the whole job. She takes your paths and she flips them, no cap 💅

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✨ OPTIONS ✨

quick vibe check before we dive in, bestie 👑 Boolean options accept either true or false as a value, or the implicit value true if neither value is specified. so like, you can be loud about it or you can just... imply it. both slay.

• --fst_align[=BOOLEAN] — Write FST data aligned where appropriate. Default: false.
• --fst_compat_symbols[=BOOLEAN] — Require symbol tables to match when appropriate. Default: true.
• --fst_default_cache_gc[=BOOLEAN] — Enable garbage collection of cache. Default: true.
• --fst_default_cache_gc_limit=N — Set the cache byte size that triggers garbage collection. Default: 1048576.
• --fst_error_fatal[=BOOLEAN] — If true, FST errors are fatal. Otherwise, returned objects are flagged as bad. For example, FSTs are returned with the kError property set to true, and FST weights set so that Member() returns false. Default: true.
• --fst_field_separator=STRING — Set the characters used as a separator between printed fields. Default: " ".
• --fst_read_mode=STRING — Set the default file reading mode for mappable files, either "read" or "map". Default: "read".
• --fst_verify_properties[=BOOLEAN] — Verify fst properties queried by TestProperties. Default: false.
• --fst_weight_parentheses=STRING — Set the characters enclosing the first weight of a printed composite weight (e.g., pair weight, tuple weight, and derived classes) to ensure proper I/O of nested composite weights. Must have size 0 (none) or 2 (open and close parenthesis). Default: no parentheses.
• --fst_weight_separator=CHARACTER — Set the character separator between printed composite weights. Default: comma.
• --help[=BOOLEAN] — Show usage information. Default: false.
• --helpshort[=BOOLEAN] — Show brief usage information. Default: false.
• --require_superinitial[=BOOLEAN] — Always create a superinitial state. Default: true.
• --save_relabel_ipairs=FILENAME — Save input relabel pairs to file. Default: do not save.
• --save_relabel_opairs=FILENAME — Save output relabel pairs to file. Default: do not save.
• --tmpdir=PATHNAME — Set the temporary directory to use. Default: /tmp.
• --v[=N] — Set the verbosity level. Default: 0.

ok real talk bestie 🌸 that --fst_weight_parentheses one is strict — size 0 or size 2, no in-between, no chaotic third option. she said boundaries. periodt.

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✨ SEE ALSO ✨

the whole friend group fr fr, go say hi 💜

fstarcsort(1), fstclosure(1), fstcompile(1), fstcompose(1), fstcompress(1), fstconcat(1), fstconnect(1), fstconvert(1), fstdeterminize(1), fstdifference(1), fstdisambiguate(1), fstdraw(1), fstencode(1), fstepsnormalize(1), fstequal(1), fstequivalent(1), fstinfo(1), fstintersect(1), fstinvert(1), fstisomorphic(1), fstlinear(1), fstloglinearapply(1), fstmap(1), fstminimize(1), fstprint(1), fstproject(1), fstprune(1), fstpush(1), fstrandgen(1), fstrelabel(1), fstreplace(1), fstreweight(1), fstrmepsilon(1), fstshortestdistance(1), fstshortestpath(1), fstsymbols(1), fstsynchronize(1), fsttopsort(1), fstunion(1)

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and that's the page, babe 🫶 this lil manual came to you courtesy of OpenFst 1.8.5, dated Mar 2026. go reverse some paths, you absolute main character 👑💖