Unix: A script without .ps1 extension passed to the powershell binary lacks invocation information ($PSCommandPath, $MyInvocation), such as when invoked via a shebang line.

[mklement0]

Steps to reproduce

Create file ./t - note the absence of extension .ps1 - with the content below and make it executable (chmod +x ./t).

#!/usr/bin/env powershell

'$PSCommandPath: ' + $PSCommandPath
'$MyInvocation.MyCommand.Path: ' + $MyInvocation.MyCommand.Path
'$MyInvocation: ' + ($MyInvocation | Out-String)

Both the following invocation methods, from bash, yield the behavior described below:

./t  # invocation via shebang line
powershell ./t   # implied -File

Expected behavior

$PSCommandPath and $MyInvocation.MyCommand.Path should reflect the script's file path, and $MyInvocation should be populated appropriately.

Actual behavior

$PSCommandPath:
$MyInvocation.MyCommand.Path:
$MyInvocation:

MyCommand             : #!/usr/bin/env powershell

                        '$PSCommandPath: ' + $PSCommandPath
                        '$MyInvocation.MyCommand.Path: ' + $MyInvocation.MyCommand.Path
                        '$MyInvocation: ' + ($MyInvocation | Out-String)

BoundParameters       : {}
UnboundArguments      : {}
ScriptLineNumber      : 0
OffsetInLine          : 0
HistoryId             : 1
ScriptName            :
Line                  :
PositionMessage       :
PSScriptRoot          :
PSCommandPath         :
InvocationName        :
PipelineLength        : 2
PipelinePosition      : 1
ExpectingInput        : False
CommandOrigin         : Runspace
DisplayScriptPosition :

Environment data

PowerShell Core v6.0.0-beta.3 on macOS 10.12.5
PowerShell Core v6.0.0-beta.3 on Ubuntu 16.04.1 LTS

[iSazonov]

Is it work well without "env"? ( #!/usr/bin/powershell)

[mklement0]

No, that doesn't make a difference.

Also keep in mind that using env (#!/usr/bin/env powershell) is the only way to portably (across Unix platforms) specify the shebang line.
(On macOS, the location is /usr/local/bin/powershell, not /usr/bin/powershell).

[iSazonov]

What parameter do the shebang use to run powershell? powershell -f filename ?

[mklement0]

#!/usr/bin/env powershell is the full shebang line, to which the system on invocation passes the absolute script file path as an argument.

In other words: the system calls env with powershell and the script file path, effectively resulting in invocation /path/to/powershell <script-file-path>.

Given that we've switched to defaulting to -File, that is all that is needed (except that to suppress the profile loading you'd also need -NoProfile - see below).

Note that portably (across Unix platforms) only one argument is supported in the shebang line, which due to using indirect invocation via env is already "used up" by the powershell argument.

macOS supports multiple arguments, but Linux does not (update: you can work around that with #!/usr/bin/env -S on recent Linux distros), so if you wanted a shebang line that is both portable and uses -NoProfile, you're out of luck.

Of course, the larger issue is that -NoProfile should be the default - see #3743

[iSazonov]

Thanks for clarify! Have we the Issue if run /path/to/powershell from bash?

[mklement0]

Yes, same issue, because these two invocation methods are effectively the same.

[iSazonov]

Please add this to first post and maybe change the Issue subject. Thanks!

[mklement0]

@iSazonov: Done.

[eedwards-sk]

This is still affecting PowerShell 7.0.0-preview.2