---
name: "vnl-tail"
section: "1"
platform: "linux"
package: "vnlog"
version: "1.40-1"
release: "Debian 13 (Trixie)"
platforms: ["linux"]
url: "https://new.carta.tech/vnl-tail"
---

# vnl-tail(1)

tail a log file, preserving the legend

## 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)](/tail/1.md) 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)](/tail/1.md)

## 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.