Sending a pipe as an argument to an external program in Powershell?

Question

I keep getting the following error when running a command to look for the most recently modified directory in my path: remotely from PowerShell:

head: The term 'head' is not recognized as the name of a cmdlet, function, script file, or operable program. Check the spelling of the name, or if a path was included, verify that the path is correct and try again.

At line 1: char: 95
+ ... d /somedir ; (lastmod=$(ls -tda -- */ | head -n 1); ....

I'm running code something along the lines of the following:

& plink "bob@server" "cd /somedir ; (lastmod=$(ls -tda -- */ | head -n 1); ls -la $lastmod)"

Answer 1

You've encapsulated your commands in double-quotes so the $ signs are being expanded by PowerShell. If you use single quotes this won't happen.

Answer 2

Just to add on to Bruce's answer, you could also escape the special character from your double-quoted string using the grave accent (`), which is the escape character in powershell.

& plink "bob@server" "cd /somedir ; (lastmod=$(ls -tda -- */ `| head -n 1); ls -la $lastmod)"

This means that if you did need any variables inside of your string, you could still utilize special characters.