SQ(1) General Commands Manual SQ(1)
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/dict/words | sq | gzip -9 > words.sq.Z
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), sort(1).
LOCAL SQ(1)
