Trying just to write a simple script that would return the SHA256 signature of a file using the file name passed to my ps1 script :

The scriptname is sha256sum.ps1.

The first argument will be any file, example :

sha256sum.ps1 dummy.exe

I tried these inside sha256sum.ps1 :

Get-FileHash -algo SHA256 %1
Get-FileHash -algo SHA256 $1
Get-FileHash -algo SHA256 $args[1]

but none of them worked.

Is there a simple way to do that ?

EDIT : Here is the final version of my script thanks to your help, guys :)

param($filename)
function calcSignature() {
    $scriptName = Split-Path -Leaf $PSCommandPath
    switch( $scriptName ) {
        "md5sum.ps1" { $algo = "MD5"; Break }
        "sha1sum.ps1" { $algo = "SHA1"; Break }
        "sha256sum.ps1" { $algo = "SHA256"; Break }
        "sha384sum.ps1" { $algo = "SHA384"; Break }
        "sha512sum.ps1" { $algo = "SHA512"; Break }
    }
    (Get-FileHash -algo $algo $filename).Hash   "  "   $filename
}

calcSignature

Now I only have one script and the others are links pointing to sha256sum.ps1.

CodePudding user response：

I'm guessing you're looking for "How to pass an argument to your .ps1 script".

This is an example of how the script sha256sum.ps1 would look:

param(
    [parameter(mandatory)]
    [validatescript({
        Test-Path $_ -PathType Leaf
    })]
    [system.io.fileinfo]$File
)

(Get-FileHash $File -Algorithm SHA256).Hash

Now, if we were to call this script, as an example:

PS \> .\sha256sum.ps1 .\test.html
1B24ED8C7929739D296DE3C5D6695CA40D8324FBF2F0E981CF03A8A6ED778C9C

Note: the current directory is where the script and the html file are located, if that was not the case, you should use the absolute path.

I would recommend you to the official docs to get a concept on functions and the param(...) block.

CodePudding user response：

Santiago's helpful answer shows how you to properly declare parameters for your script, which is generally preferable.

As for what you tried:

The automatic $args variable contains arguments not bound to any declared parameters. In other words: if your script doesn't declare any parameters, $args is the only way to access any arguments that were passed.

The first argument is at index 0, not 1.

Note:

• This differs from other shells / programming language where the element at index 0 reflects the script / program being called.
  • To get the full path of the enclosing script in PowerShell, use the automatic $PSCommandPath variable.
• Thus, for instance, %1 in a batch file and $1 in a bash script - both of which contain the first argument - correspond to $args[0] in PowerShell.

Therefore, Get-FileHash -algo SHA256 $args[0] should have worked.