Sorting a hashtable by byte value in PowerShell

22 Jul

In a PowerShell script I needed to sort a hash table by byte value (not alphabetically, lowercase parameters will be listed after uppercase ones). An example for this requirement is the Amazon Product Advertising API.

Consider the following hashtable as an example:

$params = @{}
$params.Add(&quot;AssociateTag&quot;, &quot;dummy&quot;)
$params.Add(&quot;AWSAccessKeyId&quot;, &quot;AKIAIOSFODNN7EXAMPLE&quot;)
$params.Add(&quot;IdType&quot;, &quot;0679722769&quot;)
$params.Add(&quot;Operation&quot;, &quot;ItemLookup&quot;)

$params = @{}

$params.Add("AssociateTag", "dummy")

$params.Add("AWSAccessKeyId", "AKIAIOSFODNN7EXAMPLE")

$params.Add("IdType", "0679722769")

$params.Add("Operation", "ItemLookup")

If we use the Sort-Object to order the list (note that we need to use the GetEnumerator method):

$params.GetEnumerator() | Sort-Object Name

1	$params.GetEnumerator() \| Sort-Object Name

We will get the following result:

Name                           Value                                                                                                                                                                   
----                           -----                                                                                                                                                                   
AssociateTag                   dummy                                                                                                                                                                   
AWSAccessKeyId                 AKIAIOSFODNN7EXAMPLE                                                                                                                                                    
IdType                         0679722769                                                                                                                                                              
Operation                      ItemLookup

Name Value

---- -----

AssociateTag dummy

AWSAccessKeyId AKIAIOSFODNN7EXAMPLE

IdType 0679722769

Operation ItemLookup

If you use the -CaseSensitive switch the resulting order will remain the same.

I came up with the following code (download link below) to sort the hashtable in the required order:

function Sort-Binary {
    param(
        [Parameter(Mandatory = $true,  ValueFromPipeline = $true)][HashTable]$HashTable,
        [Switch]$Descending
    )
    $keys = $HashTable.Keys | ForEach {$_}                                     
    for ($i = 0; $i -lt $keys.Count - 1; $i++) {
        for ($j = $i + 1; $j -lt $keys.Count; $j++) {
            if ($Descending) {$swap = [String]::CompareOrdinal($keys[$i], $keys[$j]) -lt 0} else {$swap = [String]::CompareOrdinal($keys[$i], $keys[$j]) -gt 0}		
            if ($swap) {$keys[$i], $keys[$j] = $keys[$j], $keys[$i]}
        }
    }
    
	$list = New-Object System.Collections.Specialized.OrderedDictionary
	$keys | ForEach { $list.Add($_, $HashTable[$_]) }
	
	return $list
}

function Sort-Binary {

param(

[Parameter(Mandatory = $true, ValueFromPipeline = $true)][HashTable]$HashTable,

[Switch]$Descending

)

$keys = $HashTable.Keys | ForEach {$_}

for ($i = 0; $i -lt $keys.Count - 1; $i++) {

for ($j = $i + 1; $j -lt $keys.Count; $j++) {

if ($Descending) {$swap = [String]::CompareOrdinal($keys[$i], $keys[$j]) -lt 0} else {$swap = [String]::CompareOrdinal($keys[$i], $keys[$j]) -gt 0}

if ($swap) {$keys[$i], $keys[$j] = $keys[$j], $keys[$i]}

}

$list = New-Object System.Collections.Specialized.OrderedDictionary

$keys | ForEach { $list.Add($_, $HashTable[$_]) }

return $list

}

Let’s try that:

$params = @{}
$params.Add(&quot;AssociateTag&quot;, &quot;dummy&quot;)
$params.Add(&quot;AWSAccessKeyId&quot;, &quot;AKIAIOSFODNN7EXAMPLE&quot;)
$params.Add(&quot;IdType&quot;, &quot;0679722769&quot;)
$params.Add(&quot;Operation&quot;, &quot;ItemLookup&quot;)

$params | Sort-Binary

Name                           Value                                                                                                                                                                   
----                           -----                                                                                                                                                                   
AWSAccessKeyId                 AKIAIOSFODNN7EXAMPLE                                                                                                                                                    
AssociateTag                   dummy                                                                                                                                                                   
IdType                         0679722769                                                                                                                                                              
Operation                      ItemLookup