filepath - Powershell's Join-Path Errs when Passing Path via Pipeline -

filepath - Powershell's Join-Path Errs when Passing Path via Pipeline -

join-path allegedly accepts path parameter pipeline.

this suggests 2 functions below should both work alike:

join-path 'c:\temp' 'x' #returns c:\temp\x 'c:\temp' | join-path 'x' #throws error

however sec phone call (i.e. using passing path parameter value pipeline) gives below error:

join-path : input object cannot bound parameters command either because command not take pipeline input or input , properties not match of parameters take pipeline input. @ line:1 char:13 + 'c:\temp' | join-path 'x' + ~~~~~~~~~~~~~ + categoryinfo : invalidargument: (c:\temp:string) [join-path], parameterbindingexception + fullyqualifiederrorid : inputobjectnotbound,microsoft.powershell.commands.joinpathcommand

nb: since path may array tried [array]('c:\temp') | join-path 'x'; made no difference.

have misunderstood something, or bug in powershell?

in first example, look join-path 'c:\temp' 'x' interpreted powershell join-path -path 'c:\temp' -childpath 'x' (because names positional parameters path , childpath optional).

in sec example, passing pipeline parameter 'c:\temp' command join-path -path 'x' (not absence of childpath parameter). not work because join-path accepts path parameter pipeline have defined it.

if want bind another, not first parameter, should write name explicitly, in

'c:\temp' | join-path -childpath 'x' # => 'c:\temp\x'

powershell filepath powershell-v4.0