NAME¶

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

SYNOPSIS¶

 $ read_temperature | tee temp.vnl
 # temperature
 29.5
 30.4
 28.3
 22.1
 ... continually produces data
 ... at the same time, in another terminal
 $ vnl-tail -f temp.vnl
 # temperature
 28.3
 22.1
 ... outputs data as it comes in

DESCRIPTION¶

  Usage: vnl-tail [options] logfile logfile logfile ... < logfile

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

• The input and output to this tool are vnlog files, complete with a legend
• "-c" is not supported because vnlog really doesn't want to break up lines
• "--zero-terminated" is not supported because vnlog assumes newline-separated records
• By default we call the "tail" 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 "tail" 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¶

tail(1)

REPOSITORY¶

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

AUTHOR¶

Dima Kogan "<dima@secretsauce.net>"

LICENSE AND COPYRIGHT¶

Copyright 2018 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.