从输入命令行参数在 PowerShell 中自动填充字典条目

Question

In PowerShell script I have a dictionary(variable input below) which I want to fill from command line arguments.

script to execute: ./win.ps1 -var1 <value> -var2 <value> -var3<value>

param($var1, $var2, $var3)
$input = @{"var1" = ""; "var2" = ""; "var3" = ""}

if ($var1){
       $input["var1"] = $var1}
if ($var2){
       $input["var2"] = $var2}
if ($var3){
       $input["var3"] = $var3}

If I have a lot of arguments can I automate the above task of filling the dictionary entry (may be in a loop), provided the key of dictionary and the param variable name, where we are receiving the input parameters are same.

Answer 1

you are using $Input as a variable. that is an automatic variable, so you likely otta NOT do that. you are likely to get some very odd results.

from Get-Help about_Automatic_Variables ...

$Input Contains an enumerator that enumerates all input that is passed to a function. The $input variable is available only to functions and script blocks (which are unnamed functions). In the Process block of a function, the $input variable enumerates the object that is currently in the pipeline. When the Process block completes, there are no objects left in the pipeline, so the $input variable enumerates an empty collection. If the function does not have a Process block, then in the End block, the $input variable enumerates the collection of all input to the function.

hope that helps,
lee

Answer 2

I would suggest you to have it in a csv file and pass the file to the script.

Name                           Value
----                           -----
var2                           2
var3                           3
var1                           1

And inside your script

$HashTable = Import-Csv -Path $CSVPath | ForEach-Object -Process { @{$_.Name=$_.Value} }

Answer 3

Just use $args variable, and use it for set an hashtable. Remove param($var1, $var2, $var3) into your script, its not necessary in your case

Answer 4

You could use $args automatic variable and hashtable to hold parameter name and its value. Like so:

function Do-Things{

    $hashtable = @{}
    for ($i = 0; $i -lt $args.Count; $i += 2)
    { 
       $hashtable[$args[$i]] = $args[$i+1] 
    }
    $hashtable
}
$Results = Do-Things -af df -fds 421 -fgsd hfd
$Results

Output:

Name                           Value                                                                                                                                                               
----                           -----                                                                                                                                                               
-fds                           421                                                                                                                                                                 
-fgsd                          hfd                                                                                                                                                                 
-af                            df  

You could also access specific keys:

$Results['-af']

Output:

df

Also, like @Lee_Dailey already mention do not use $Input automatic variable to hold data.