I can tail one file via the following command:
Get-Content -Path C:\log1.txt -Tail 10 –Wait
How do I extend this to multiple files, I have tried the following with no luck:
Get-Content -Path C:\log1.txt,C:\log2.txt -Tail 10 –Wait
This will only pick up updates from the first file, not the second.
Based on @mjolinor's comment, I have come up with the following that appears to work,
Workflow My-Tail
{
Param([string[]] $Path)
foreach -parallel ($file in $path)
{
Get-Content -Path $file -Tail 1 -Wait
}
}
My-Tail (dir C:\*.log -Include log1.txt,log2.txt)
However, this has some sort of progress bar that appears...
$ProgressPreference='SilentlyContinue' in the script to suppress the progress bar. I'm working on my own version that will also highlight and filter lines. github.com/McLeopold/TailorPosh
I can't speak to how efficient this is, but since I'm using PowerShell Core 7.1.3, I can't use Workflows or ForEach -Parallel, but I can use ForEach-Object -Parallel, so I tried it just to see what would happen...
Get-ChildItem -Path C:\ -Filter log*.txt |
ForEach-Object -Parallel {
Get-Content -Wait -Tail 10 -Path $_
} -ThrottleLimit 30
In my case, I had 27 files I needed to monitor, so I chose a number just above that, and this seemed to work.
Just to be sure it was working, I used this, which will output the source file name before each line:
Get-ChildItem -Path C:\ -Filter log*.txt |
ForEach-Object -Parallel {
$file = $_;
Get-Content -Wait -Tail 10 -Path $file |
ForEach-Object { Write-Output "$($file.Name): ${_}" }
} -ThrottleLimit 30
Incorporating @McLeopold's comment into @Cheetah's code
function Tail (
[Parameter(Mandatory=$true)][string[]]$Files,
[long]$Tail = 1
) {
workflow TailWorkflow (
[string[]]$Files,
[long]$Tail
) {
foreach -parallel ($File in $Files) {
Get-Content -Tail $Tail $File -Wait
}
}
$ProgressPreference='SilentlyContinue'
TailWorkflow -Files $Files -Tail $Tail
}
I needed tailed output across multiple files and I wanted to try do it in one line,
here's what I eventually came up with:
gci *.txt -recurse | ForEach-Object { Write-Output "$_`n" + $(Get-Content $_ -tail 5) + "`n" }
Its takes a recursive directory listing of all files named *.txt,
writes the file path to console,
then writes the last 5 lines to console.
I didn't need to follow the tails of the files, they weren't being actively written to.
