fstcompile(1)

💅 fstcompile — the manual page, but make it make sense

omg hi bestie 🫶 so this is fstcompile(1) from the User Commands manual section, and it's honestly one of the most useful little tools in the OpenFst lineup. Let's get into it. ✨

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✨ NAME ✨

fstcompile — compile text FSTs to binary FSTs

Like, it takes your cute little human-readable text FST and turns it into the ✨binary✨ glow-up. 💖

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🌸 SYNOPSIS 🌸

fstcompile [OPTIONS] [text.fst [binary.fst]]

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🦋 DESCRIPTION 🦋

Creates binary FSTs from a simple text format. That's it. That's the whole vibe. 🎀

You hand it text, it hands you a binary FST, and everyone claps. 👑

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💅 OPTIONS 💅

okay so first, the rules of the game:

Boolean options accept either true or false as a value, or they just silently take the implicit value true if you don't specify a value at all. Iconic behaviour, lowkey. 😌

• --acceptor[=BOOLEAN] — Treat the input as being in acceptor format. Default: false. 🍓
• --allow_negative_labels[=BOOLEAN] — Allow negative labels. Bestie, this is not recommended — it may cause conflicts. Default: false. 💀
• --arc_type=TYPE — Set the output arc type. Default: standard.
• --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 the 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 get flagged as bad — like, FSTs come back with the kError property set to true, and FST weights get 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_type=TYPE — Set the output FST type. Default: vector.
• --fst_verify_properties[=BOOLEAN] — Verify the 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) so that nested composite weights do proper I/O. 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.
• --isymbols=FILENAME — Set the input label symbol table. Default: "".
• --keep_isymbols[=BOOLEAN] — Store the input label symbol table with the FST. Default: false. 💜
• --keep_osymbols[=BOOLEAN] — Store the output label symbol table with the FST. Default: false. 💜
• --keep_state_numbering[=BOOLEAN] — Do not renumber input states. Default: false.
• --osymbols=FILENAME — Set the output label symbol table. Default: "".
• --save_relabel_ipairs=FILENAME — Save input relabel pairs to a file. Default: do not save. 🙈
• --save_relabel_opairs=FILENAME — Save output relabel pairs to a file. Default: do not save. 🙈
• --ssymbols=FILENAME — Set the state label symbol table. Default: "".
• --tmpdir=PATHNAME — Set the temporary directory to use. Default: /tmp.
• --v[=N] — Set the verbosity level. Default: 0. 🔊

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🌈 SEE ALSO 🌈

the whole friend group fr fr:

fstarcsort(1), fstclosure(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), 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 page bestie, you ate it up 💅✨

Cute little sign-off: this is from OpenFst 1.8.5, dated Mar 2026. periodt. 🎀🦋