PowerShell is definitely gaining momentum in the windows scripting world but I still hear folks wanting to rely on Unix based tools to get their job done. In this series of posts I’m going to look at converting some of the more popular Unix based tools to PowerShell.
touch
The Unix “touch” command is used to change a file’s access and modification timestamps. It can also be used to create a new empty file.
The options to the Unix touch command are implemented with the following PowerShell parameters:
| Unix | PowerShell | Description |
|---|---|---|
| FILE | -filespec | The files to modify. |
| -d | -datetime | Parse STRING and use it instead of current time. |
| -F | -forward | Modify the time by going forward SECONDS seconds. |
| -r | -reference | Use this file as a reference instead of the current time. |
| -m | -only_modification | Change only the modification time. |
| -a | -only_access | Change only the access time. |
1: #----------------------------------------------------------------
2: # Touch.ps1
3: #----------------------------------------------------------------
4: param
5: (
6: [string]$filespec = $null, # Files to touch
7: [DateTime]$datetime = ([DateTime]::Now), # Use DateTime STRING instead of current time.
8: [int]$forward = 0, # Modify the time by going forward SECONDS s.
9: [string]$reference = $null, # Use this file's time instead of current time.
10: [bool]$only_modification = $false, # Change only the modification time.
11: [bool]$only_access = $false # Change only the access time
12: );
13:
14: #----------------------------------------------------------------
15: # Function Do-Touch
16: #----------------------------------------------------------------
17: function Do-Touch {
18: param(
19: [string]$filespec = $null,
20: [datetime]$datetime = ([DateTime]::Now),
21: [int]$forward = 0,
22: [string]$reference = $null,
23: [bool]$only_modification = $false,
24: [bool]$only_access = $false
25: );
26:
27: $touch = $null;
28:
29: if ( $filespec )
30: {
31: $files = @(Get-ChildItem -Path $filespec -ErrorAction SilentlyContinue)
32: if ( !$files )
33: {
34: # If file doesn't exist, attempt to create one.
35: # A wildcard patter will fail silently.
36: Set-Content -Path $filespec -value $null;
37: $files = @(Get-ChildItem -Path $filespec -ErrorAction SilentlyContinue);
38: }
39:
40: if ( $files )
41: {
42: if ( $reference )
43: {
44: $reffile = Get-ChildItem -Path $reference -ErrorAction SilentlyContinue;
45: if ( $reffile )
46: {
47: [datetime]$touch = $reffile.LastAccessTime.AddSeconds($forward);
48: }
49: }
50: elseif ( $datetime )
51: {
52: [datetime]$touch = $datetime.AddSeconds($forward);
53: }
54:
55: if ( $touch )
56: {
57: [DateTime]$UTCTime = $touch.ToUniversalTime();
58: foreach ($file in $files)
59: {
60: if ( $only_access )
61: {
62: $file.LastAccessTime=$touch
63: $file.LastAccessTimeUtc=$UTCTime
64: }
65: elseif ( $only_modification )
66: {
67: $file.LastWriteTime=$touch
68: $file.LastWriteTimeUtc=$UTCTime
69: }
70: else
71: {
72: $file.CreationTime = $touch;
73: $file.CreationTimeUtc = $UTCTime;
74: $file.LastAccessTime=$touch
75: $file.LastAccessTimeUtc=$UTCTime
76: $file.LastWriteTime=$touch
77: $file.LastWriteTimeUtc=$UTCTime
78: }
79: $file | select Name, *time*
80: }
81: }
82: }
83: }
84: }
85:
86: Do-Touch -filespec $filespec -datetime $datetime -forward $forward -reference $reference `
87: -only_modification $only_modification -only_access $only_access;
You can download the full script here: Touch.ps1