Watch file for changes and run command with powershell

Question

Is there any simple way(i.e., script) to watch file in Powershell and run commands if file changes. I have been googling but can\'t find simple solution. Basically I run scr

Answer 1

Here is another option.

I just needed to write my own to watch and run tests within a Docker container. Jan's solution is much more elegant, but FileSystemWatcher is broken within Docker containers presently. My approach is similar to Vasili's, but much lazier, trusting the file system's write time.

Here's the function I needed, which runs the command block each time the file changes.

function watch($command, $file) {
    $this_time = (get-item $file).LastWriteTime
    $last_time = $this_time
    while($true) {
        if ($last_time -ne $this_time) {
            $last_time = $this_time
            invoke-command $command
        }
        sleep 1
        $this_time = (get-item $file).LastWriteTime
    }
}

Here is one that waits until the file changes, runs the block, then exits.

function waitfor($command, $file) {
    $this_time = (get-item $file).LastWriteTime
    $last_time = $this_time
    while($last_time -eq $this_time) {
        sleep 1
        $this_time = (get-item $file).LastWriteTime
    }
    invoke-command $command
}