fstinvert(1)

💅 fstinvert — the manual, but make it cute

okay bestie, gather round, because this is fstinvert(1) from the User Commands corner of the OpenFst cinematic universe, and she is serving simplicity. one job. one tiny little flip. let's get into it 🦋

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✨ NAME ✨

fstinvert — invert a transduction 💫

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🎀 SYNOPSIS 🎀

fstinvert [OPTIONS] [in.fst [out.fst]]

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🔥 DESCRIPTION 🔥

Inverts a transduction. that's it. that's the whole plot. short king behavior, honestly 👑

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💖 OPTIONS 💖

okay so listen: boolean options are chill like that — you can hand them either true or false as a value, OR you can just say the option with no value at all and it'll implicitly be true. no value = yes babes. 🫶

• --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.
• --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.

bestie warning 📢 — that --fst_weight_parentheses one has rules. it must be size 0 (none) or 2 (open and close parenthesis). no in-between, no "just one bracket and see what happens". the math said no. 🙈

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🌈 SEE ALSO 🌈

the whole girl group, alphabetized and everything, because they roll deep:

• 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), fstisomorphic(1), fstlinear(1), fstloglinearapply(1), fstmap(1), fstminimize(1), fstprint(1), fstproject(1), fstprune(1), fstpush(1), fstrandgen(1), fstrelabel(1), fstreplace(1), fstreverse(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 whole thing, you're literally a transduction-flipping legend now 💜 go invert something and text me how it went.

this has been OpenFst 1.8.5, dated Mar 2026 — mwah, periodt 💋