fstconcat(1)

✨ fstconcat(1) — the concatenate-two-FSTs girlies' manual ✨

okay so bestie, welcome to fstconcat, a User Commands girly from the OpenFst family 💅 she eats, she slays, she glues two FSTs together. that's the whole vibe. iykyk.

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🌸 NAME 🌸

fstconcat — concatenate two FSTs 🫶

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✨ SYNOPSIS ✨

fstconcat [OPTIONS] in1.fst in2.fst [out.fst]

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💖 DESCRIPTION 💖

Concatenates two FSTs. literally her entire job. no cap. two in, one out, iconic behavior. 👑

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🎀 OPTIONS 🎀

quick lil note before we dive in, babes: Boolean options accept either true or false as a value, or the implicit value true if you don't specify a value at all. so like, no value = yes. periodt.

• --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 pls note: --fst_weight_parentheses is giving "must have size 0 or 2" and nothing else, so don't try to be cute with a size of 1. it will not go well. 💀

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🦋 SEE ALSO 🦋

her whole friend group, fr fr — go read these next:

fstarcsort(1), fstclosure(1), fstcompile(1), fstcompose(1), fstcompress(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!! 🎀 this gorgeous thing shipped as part of OpenFst 1.8.5 and the manual itself is dated Mar 2026 — so yeah, lowkey fresh, highkey iconic. go concat something. slay. ✨🦋🌈👑💖