---
name: "hfst-lookup"
section: "1"
platform: "linux"
package: "hfst"
version: "3.16.2-1+b1"
release: "Debian 13 (Trixie)"
platforms: ["linux"]
url: "https://new.carta.tech/hfst-lookup"
---

# hfst-lookup(1)

\=perform transducer lookup (apply)

## NAME

hfst-lookup - =perform transducer lookup (apply)

## SYNOPSIS

**hfst-lookup** \[*OPTIONS*...\] \[*INFILE*\]

## DESCRIPTION

perform transducer lookup (apply) NOTE: hfst-lookup does lookup from left to right as opposed to xfst and foma

-

  lookup which is carried out from right to left. In order to do lookup in a similar way as xfst and foma, use 'hfst-flookup' instead.

### Common options:

- **-h**, **--help**

  Print help message

- **-V**, **--version**

  Print version info

- **-v**, **--verbose**

  Print verbosely while processing

- **-q**, **--quiet**

  Only print fatal erros and requested output

- **-s**, **--silent**

  Alias of **--quiet**

### Input/Output options:

- **-i**, **--input**=*INFILE*

  Read input transducer from INFILE

- **-o**, **--output**=*OUTFILE*

  Write output to OUTFILE

**-p**, **--pipe-mode**\[=*STREAM*\] Control input and output streams

### Lookup options:

- **-I**, **--input-strings**=*SFILE*

  Read lookup strings from SFILE

- **-O**, **--output-format**=*OFORMAT*

  Use OFORMAT printing results sets

- **-e**, **--epsilon-format**=*EPS*

  Print epsilon as EPS

- **-F**, **--input-format**=*IFORMAT*

  Use IFORMAT parsing input

- **-x**, **--statistics**

  Print statistics

- **-X**, **--xfst**=*VARIABLE*

  Toggle xfst VARIABLE

- **-c**, **--cycles**=*INT*

  How many times to follow input epsilon cycles (only for non-lookup-optimized transducers)

- **-n**, **--max-number**=*INT*

  Maximum number of results printed for each input (only for lookup-optimized transducers)

- **-b**, **--beam**=*B*

  Output only analyses whose weight is within B from the best analysis

- **-t**, **--time-cutoff**=*S*

  Limit search after having used S seconds per input (only for lookup-optimized transducers)

- **-C**, **--cascade**=*CASCADE*

  How multiple transducers in input are handled

- **-P**, **--progress**

  Show neat progress bar if possible

If OUTFILE or INFILE is missing or -, standard streams will be used. Format of result depends on format of INFILE OFORMAT is one of {xerox,cg,apertium}, xerox being default IFORMAT is one of {text,spaced,apertium}, default being text, unless OFORMAT is apertium VARIABLEs relevant to lookup are {print-pairs,print-space, quote-special,show-flags,obey-flags} Input epsilon cycles are followed by default INT=5 times. Epsilon is printed by default as an empty string. B must be a non-negative float. S must be a non-negative float. The default, 0.0, indicates no cutoff. If the input contains several transducers, a set containing results from all transducers is printed for each input string.

CASCADE must be one of { union, priority-union, composition }. If not specified, defaults to {union}.

STREAM can be { input, output, both }. If not given, defaults to {both}. If input file is not specified with **-I**, input is read interactively line by line from the user. If you redirect input from a file, use **--pipe-mode**=*input*. **--pipe-mode**=*output* is ignored on non-windows platforms.

### Todo:

-

  Support **--xfst**=*obey-flags* for optimized lookup format. Support **--cycles** for optimized lookup format.

### Known bugs:

-

  'quote-special' quotes spaces that come from 'print-space'

## REPORTING BUGS

Report bugs to \<hfst-bugs@helsinki.fi\> or directly to our bug tracker at: \<https://github.com/hfst/hfst/issues\>

hfst-lookup home page: \<https://github.com/hfst/hfst/wiki/HfstLookup\>\
 General help using HFST software: \<https://github.com/hfst/hfst/wiki\>

## COPYRIGHT

Copyright © 2017 University of Helsinki, License GPLv3: GNU GPL version 3 \<http://gnu.org/licenses/gpl.html\>\
 This is free software: you are free to change and redistribute it. There is NO WARRANTY, to the extent permitted by law.