VNL-UNIQ

NAME

vnl-uniq - uniq a log file, preserving the legend

SYNOPSIS

$ cat colors.vnl
# color
blue
yellow
yellow
blue
yellow
orange
orange
$ < colors.vnl | vnl-sort | vnl-uniq -c
# count color
2 blue
2 orange
3 yellow

DESCRIPTION

Usage: vnl-uniq [options] < logfile

This tool runs "uniq" on a given vnlog dataset. "vnl-uniq" is a wrapper around the GNU coreutils "uniq" tool. Since this is a wrapper, most commandline options and behaviors of the "uniq" tool are present; consult the uniq(1) manpage for detail. The differences from GNU coreutils "uniq" are

	•		The input and output to this tool are vnlog files, complete with a legend
	•		"--zero-terminated" is not supported because vnlog assumes newline-separated records
	•		Only one input is supported (a file on the cmdline or data on standard input), and the output always goes to standard output. Specifying the output as a file on the commandline is not supported.
	•		"--vnl-count NAME" can be given to name the "count" column. "-c" is still supported to add the default new column named "count", but if another name is wanted, "--vnl-count" does that. "--vnl-count" implies "-c"
	•		In addition to the normal behavior of skipping fields at the start, "-f" and "--skip-fields" can take a negative argument to skip the all but the last N fields. For instance, to use only the one last field, pass "-f -1" or "--skip-fields=-1".
	•		By default we call the "uniq" tool to do the actual work. If the underlying tool has a different name or lives in an odd path, this can be specified by passing "--vnl-tool TOOL"

Past that, everything "uniq" does is supported, so see that man page for detailed documentation.

COMPATIBILITY

I use GNU/Linux-based systems exclusively, but everything has been tested functional on FreeBSD and OSX in addition to Debian, Ubuntu and CentOS. I can imagine there’s something I missed when testing on non-Linux systems, so please let me know if you find any issues.

SEE ALSO

uniq(1)

REPOSITORY

https://github.com/dkogan/vnlog/

AUTHOR

Dima Kogan "<dima@secretsauce.net>"

LICENSE AND COPYRIGHT

Copyright 2019 Dima Kogan "<dima@secretsauce.net>"

This library is free software; you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License as published by the Free Software Foundation; either version 2.1 of the License, or (at your option) any later version.