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/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 pre‐
       fix  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).



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