---
name: "unsq"
section: "1"
platform: "linux"
package: "ispell"
version: "3.4.00-6+b1"
release: "Debian 10 (Buster)"
platforms: ["linux"]
url: "https://new.carta.tech/sq"
---

# unsq(1)

squeeze or unsqueeze a sorted word list

Part of [sq(1)](/sq/1.md).

## NAME

sq, unsq - squeeze or unsqueeze a sorted word list

## SYNOPSIS

**sq** \< infile \> outfile

**unsq** \< infile \> outfile

## DESCRIPTION

*sq* compresses a sorted list of words (a dictionary).  For example:

sort -u /usr/share/dict/words \| sq \| gzip -9 \> words.sq.gz

will compress dict by about a factor of 5.

*unsq* uncompress the output of *sq.* For example:

gunzip \< words.sq.gz \| unsq \| sort -f -o words

will uncompress a dictionary compressed with *sq.*

The squeezing is achieved by eliminating common prefixes, and replacing them with a single character which encodes the number of characters shared with the preceding word. The prefix size is encoded as a single printable character: 0-9 represent 0-9, A-Z represent 10-35, and a-z represent 36-61.

## BUGS

*sq* and *unsq* can only handle words of up to 256 characters. The input must be sorted, and duplicates must be suppressed.

## AUTHOR

Mike Wexler

## SEE ALSO

[compress(1)](/compress/1.md), [sort(1)](/sort/1.md).