Passing empty arguments to executables using power

问题:

Powershell seems to drop empty string arguments when passed to a command. I have this code

PS D:\> $b.name = "foo bar"
PS D:\> ./echoargs $b.name
Arg 0 is D:\echoargs.exe
Arg 1 is foo bar
PS D:\> $b.name = ""
PS D:\> ./echoargs $b.name
Arg 0 is D:\echoargs.exe

You can assume that $b has a 'name' member. How can i pass this as an argument to the exe even when the value is an empty string. I've tried using the call operator with no success.

回答1:

If you want an empty string to appear try escaped quotes around the argument like so:

PS> $b = [psobject]@{name = ''}
PS> echoargs `"$($b.Name)`"
Arg 0 is <>

Command line:
"C:\Users\Keith\Pscx\Trunk\Src\Pscx\bin\Release\Apps\EchoArgs.exe"  ""

Note that I tested this on V3 so I'm not sure if the behavior will be exactly the same on V2.

回答2:

Try to pass an empty single quote string enclosed in double quotes, or vice versa.

./echoargs $b.name, "''"

or

./echoargs $b.name, '""'

回答3:

This should also work:

./echoargs [String]::Empty