How To Tail With PowerShell

Printing the last or first, few lines of a file is a common operation in day to day operations.
On Linux most people will, without thinking twice, use tail and it's counterpart head to achieve this.

It's man page¹ describes tail simply like this

Print the last 10 lines of each FILE to standard output.
With more than one FILE, precede each with a header giving the file name.

Lets take a look at some common tail operations and how to reproduce them with PowerShell.

tail -f

tail -f /var/log/important.log

This is my personal top use case for tail. The -f switch instructs tail to follow the given file,
outputting data as it is written to the file.

With PowerShell we will use Get-Content and instruct it to follow the file with the -Wait switch.

Get-Content "c:\important.log" -Wait

Important!

There is one important difference to tail.
If the file being followed gets deleted the process will return with a non-zero code.

Terminating is the same with both tail and Get-Content, just press Ctrl+C

tail -n

The -n parameter instructs tail to return the last X lines from the given file.

Let's say you want the last 20 lines from your important log file

tail -n 20 /var/log/important.log

PowerShell can replicate this behavior with the -Tail parameter.

Get-Content "c:\important.log" -Tail 20

head -n

Head works the same way, but takes the first X lines from the given file.

head -n 20 /var/log/important.log

PowerShell can replicate this behavior with the -Head parameter.

Get-Content "c:\important.log" -Head 20

Multiple Files

Coming back to our tail -f example you may want to operate on multiple files at once.

With tail you can simply append them to the end of the command like this.

tail -f /var/log/important.log /var/log/another.log

Not surprisingly Get-Content works in a similar way.

Get-Content "c:\important.log","c:\another.log" -Wait

Important!

• Unlike tail the different files need to be comma-separated
• PowerShell will not indicate what file a outputted line belongs to

Shortcuts

Writing out Get-Content every time may seem a bit long winded or cumbersome, thankfully you don't have to.

With some shortcuts you can significantly lower keystrokes:

• Shorten Get-Content by using it's alias gc
• Omit "" around your paths as long as they have no spaces inside
• Commands are always case insensitive, this is more of a personal preference

With this shortcuts our commands are way shorter.

Get-Content "c:\important.log" -Wait
gc c:\important.log -Wait

Get-Content "c:\important.log" -Tail 20
gc c:\important.log -Tail 20

Get-Content "c:\important.log" -Head 20
gc c:\important.log -Head 20

Get-Content "c:\important.log","c:\another.log" -Wait
gc c:\important.log,c:\another.log -Wait

Taking It Further

This covers examples for basic tail usage to get you started in PowerShell.

Additionally you can use a wide variety of wildcards inside the path to filter for multiple files to tail.

Get-Content "c:\logs\*" -Wait

Advancing from there you may want to exclude some irrelevant IIS logs and a few old log files from 2019.

Get-Content "c:\logs\*" -Exclude "iis-*.log","*2019*" -Wait

A great ressource to dive in even deeper is the official documentation from microsoft.

Feel free to ask me about your PowerShell problem over on Twitter!

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1. http://manpages.ubuntu.com/manpages/focal/en/man1/tail.1.html ↩