#42 : How to change modified date of file using Powershell?

I always had a technique in Unix which converts modified date of a file. But never tried the same in Windows. But it was again possible in Windows using MKS Toolkit or Cygwin. There are very rare situation where you need to modified date of file. I don't want to go depth of reason, let's see
how we can do it.

DESCRIPTION

Run the below command:
ls

Directory: C:\Users\admin\Downloads


Mode LastWriteTime Length Name
---- ------------- ------ ----
-a--- 9/22/2012 9:37 PM 4750740 Setup_BullzipPDFPrinter_9_0_0_1437.zip
-a--- 9/23/2012 10:10 PM 58158 webcam-toy-photo1.jpg
-a--- 9/23/2012 10:10 PM 58158 webcam-toy-photo2.jpg


Ok, you may notice the LastWriteTime column. This column can be simply used to change the date and time.

Let's rename webcam-toy-photo2.jpg with modified date as 9/23/1942 10:10 PM.

Run the below command:

ls | where { $_.Name -eq "webcam-toy-photo2.jpg" } | foreach { $_.LastWriteTime="9/23/1942 10:10 PM" }

Let's check the date again. The date is of 1942.

ls

Directory: C:\Users\admin\Downloads


Mode LastWriteTime Length Name
---- ------------- ------ ----
-a--- 9/22/2012 9:37 PM 4750740 Setup_BullzipPDFPrinter_9_0_0_1437.zip
-a--- 9/23/2012 10:10 PM 58158 webcam-toy-photo1.jpg
-a--- 9/23/1942 10:10 PM 58158 webcam-toy-photo2.jpg


Enjoy Scripting!!

#41 : View Process Commandline with Powershell

Process can be viewed easily in Powershell with Get-Process command. This command is useful, but it has some shortcomings -
1. It does not show the command-line and arguments passed to the command.
2. It does not show the Path of command.

Due to these shortcomings, I started looking for some option by which we can get the list of processes with complete details. The search completed and it came with WMI and Powershell combination. Below is the single line which can solve this problem.

Get-WmiObject Win32_process |   select  ParentProcessId, ProcessId, Name, Commandline  | ft

Based on the above, you can write a script which could kill processes by specific application, but be careful, killing a operating system process might shutdown the machine.

Happy scripting!!

#40 : Reading, Updating and Inserting Data into Excel with Powershell

We often find ourself into a situation when we have to create or write into Excel sheet. This tasks can be done with two ways -
1. Using Excel COM object
2. Using Jet Engine

Using COM object is fairly simple and anyone can copy and paste from a list of sources. The drawback of using Excel COM object is that you need to have Excel application installed on the machine. But this condition is not applicable to production servers where mostly Excel and other Microsoft office tools are not installed due to security threats. Basically you will find them installed on your workstations. Considering these points I was looking for a good method to connect to Excel and update some records in Excel sheet.

Without wasting your time and mine too, let's look into code which can do it for you. I know, if you are good programmer, you don't have to break your head much. If you are a beginner, this blog is not that suitable (I must say). I am busy person and I don't have this only job (Sorry).

1. Sample Code to read data from Excel sheet -

Testing Preparations:
1. Create an Excel document. (If you don't have Microsoft Office in your workstation, you may ask your IT dept. to install OpenOffice or LiberOffice).
2. On first row of sheet as Name and insert some records-
Name
Som
Manu
Ravi
Akash

3. Save and close the doc. I assume, you saved it as F:\test.xls.

Code to Read data from Excel Sheet-

$strFileName ="F:\test.xls"
$strSheetName = 'Sheet1$'
$strProvider = "Provider=Microsoft.Jet.OLEDB.4.0"
$strDataSource = "Data Source = $strFileName"
$strExtend = "Extended Properties=Excel 8.0"
$strQuery = "Select * from [$strSheetName]"

$strQuery = "Select * from [$strSheetName]"
$objConn = New-Object System.Data.OleDb.OleDbConnection("$strProvider;$strDataSource;$strExtend")
$sqlCommand = New-Object System.Data.OleDb.OleDbCommand($strQuery)
$sqlCommand.Connection = $objConn
$objConn.open()
$DataReader = $sqlCommand.ExecuteReader()

While($DataReader.read())
{
$ComputerName = $DataReader[0].Tostring() 
echo $ComputerName 
}  
$dataReader.close()
$objConn.close()

Code to Update data in Excel Sheet-
(Below code will update all names with Som)

$strFileName ="F:\test.xls"
$strSheetName = 'Sheet1$'
$strProvider = "Provider=Microsoft.Jet.OLEDB.4.0"
$strDataSource = "Data Source = $strFileName"
$strExtend = "Extended Properties=Excel 8.0"

$strQuery = "Update [$strSheetName] set Name = 'Som' "
$objConn = New-Object System.Data.OleDb.OleDbConnection("$strProvider;$strDataSource;$strExtend")
$sqlCommand = New-Object System.Data.OleDb.OleDbCommand($strQuery)
$sqlCommand.Connection = $objConn
$objConn.open()
$sqlCommand.ExecuteNonQuery()
$objConn.Close()

Code to Insert data in Excel Sheet-
(Below code will insert one more row)

$strFileName ="F:\test.xls"
$strSheetName = 'Sheet1$'
$strProvider = "Provider=Microsoft.Jet.OLEDB.4.0"
$strDataSource = "Data Source = $strFileName"
$strExtend = "Extended Properties=Excel 8.0"

$strQuery = "Insert into [$strSheetName] values ('Ravi')"
$objConn = New-Object System.Data.OleDb.OleDbConnection("$strProvider;$strDataSource;$strExtend")

$sqlCommand = New-Object System.Data.OleDb.OleDbCommand($strQuery)

$sqlCommand.Connection = $objConn
$objConn.open()

$sqlCommand.ExecuteNonQuery()
$objConn.Close()

Hope, this will help you.

Enjoy scripting!!

#39 : How to write in Windows Event Log with Powershell?

Happy new year!

It has been long since I wrote something in this blog. Basically I got
busy with ASP.NET Programming and I am paying more attention to ASP.NET
these days. Ok, let's start with this.


GENERAL DESCRIPTION

Writing into Windows Event log requires two steps:

1. Creating a log entry about the application. This is mandatory to have
an entry for your application or script in Eventlog. The below statement
will fail if the source name already exists.

New-EventLog -LogName Application -Source "YourScriptName"


2. Writing into EventLog
It can be done with the below stateement:

Write-EventLog -logname Application -source "YourScriptName" -eventID 3001
-entrytype Information -message "The message you want" -category 1
-rawdata 10,20

IMPLEMENTATION

I would suggest it can be implemented with below concept:
I will create a single function in my script which will log from several
locations. So, this will be easier for you to use the same function
everywhere.


$SCRIPT_NAME="MyScriptName"

function log_this([string]$MESSAGE)
{

if ( !([System.Diagnostics.EventLog]::SourceExists($SCRIPT_NAME)) )
{
New-EventLog -LogName Application -Source $SCRIPT_NAME
}

Write-EventLog -logname Application -source $SCRIPT_NAME -eventID 3001
-entrytype Information -message $MESSAGE -category 1 -rawdata 10,20

}

log_this "Failed to peform something"


CMDLETS USED

Write-EventLog
New-EventLog


CONCLUSION

As you saw above, I have used [System.Diagnostics.EventLog]::SourceExists
method for find the existence of your application. This method is really
useful because, if you do not know whether your application/script source
name is entered or not, it will throw error.


with regards,
Som Dutt Tripathi

#38 : Powershell script to Map Network drive

We often need to map network drives. Especially if you are writing a package which installs something from a shared drive. It becomes important to map drives and give a drive letter for the same.

Net share is the command which can be used to accomplish the same. Below is the Powershell version of the same -

Adding a Network Drive 
(New-Object -Com WScript.Network).MapNetworkDrive("x:" , "\\divine\d$")

That's it!
But this not the all about this. There might be further requirement to remove a network drive.


Listing the Network Drives
(New-Object -Com WScript.Network).EnumNetworkDrives()


Removing a Network Drive
(New-Object -Com WScript.Network).RemoveNetworkDrive("x:")

You can use EnumNetworkDrives() to find if particular share exists or not, then remove it. Anyways, there are several methods to do something, my job was just to give your tips not thesis.

Enjoy!!

#37 : Download Files from Internet with Powershell

Powershell can be used to download a file from internet. This might help you matching some item from internet or you can create a download manager kind of software in Powershell.

Actually, you can do nearly everything which you can do in C# or any .NET based programming language because, .NET framework is common to C#, VB.NET and Powershell as well. Both Powershell or C# compile the code into MSIL (Microsoft Intermediate Language). But the only difference is Powershell is in form of script and C# will be a program. 

Powershell scripts can be compiled using C#, but again the compiled executable will require Powershell be installed on the machine. This cannot be called as standalone executable, but again I think "Can you run a C# code when .NET framework is not installed?". Anyways, lets not waste more time in thinking, below is the piece of code- 

(new-object System.Net.WebClient).Downloadfile("http://www.freeware995.com/bin/pdfedit.exe", "d:\pdfedit.exe")

Above is smallest inner line of a possible big code which will handle download of files from Internet. 

For sake of simplicity, I always prefer to give a one-liner. The reason is, when you want to know how to do something, your intention is basically to get something too small which can be further enhanced in your program. When I search, I look for a small code and I hope everyone does. There is no point is providing a complex code which you could not understand or incorporate in your code!

Enjoy scripting!!

#36 : How to find CPU Usage Percent with Powershell?

Hi All,

CPU-Utilization can be achieved with the command below -

Get-WmiObject win32_processor | select LoadPercentage | fl

Let's dissect the line and try to understand -


Posh (0016) > Get-WmiObject win32_processor


__GENUS                     : 2
__CLASS                     : Win32_Processor
__SUPERCLASS                : CIM_Processor
__DYNASTY                   : CIM_ManagedSystemElement
__RELPATH                   : Win32_Processor.DeviceID="CPU0"
__PROPERTY_COUNT            : 48
__DERIVATION                : {CIM_Processor, CIM_LogicalDevice, CIM_LogicalElement, CIM_ManagedSystemElement}
__SERVER                    : DIVINE
__NAMESPACE                 : root\cimv2
__PATH                      : \\DIVINE\root\cimv2:Win32_Processor.DeviceID="CPU0"
AddressWidth                : 32
Architecture                : 9
Availability                : 3
Caption                     : x64 Family 6 Model 23 Stepping 10
ConfigManagerErrorCode      :
ConfigManagerUserConfig     :
CpuStatus                   : 1
CreationClassName           : Win32_Processor
CurrentClockSpeed           : 1196
CurrentVoltage              : 16
DataWidth                   : 64
Description                 : x64 Family 6 Model 23 Stepping 10
DeviceID                    : CPU0
ErrorCleared                :
ErrorDescription            :
ExtClock                    : 200
Family                      : 185
InstallDate                 :
L2CacheSize                 : 1024
L2CacheSpeed                :
L3CacheSize                 : 0
L3CacheSpeed                : 0
LastErrorCode               :
Level                       : 6
LoadPercentage              : 1
Manufacturer                : GenuineIntel
MaxClockSpeed               : 2300
Name                        : Pentium(R) Dual-Core CPU       T4500  @ 2.30GHz
NumberOfCores               : 2
NumberOfLogicalProcessors   : 2
OtherFamilyDescription      :
PNPDeviceID                 :
PowerManagementCapabilities :
PowerManagementSupported    : False
ProcessorId                 : BFEBFBFF0001067A
ProcessorType               : 3
Revision                    : 5898
Role                        : CPU
SocketDesignation           : uPGA-478
Status                      : OK
StatusInfo                  : 3
Stepping                    :
SystemCreationClassName     : Win32_ComputerSystem
SystemName                  : DIVINE
UniqueId                    :
UpgradeMethod               : 185
Version                     :
VoltageCaps                 :




The result shows overall CPU-Utilization which can be matched with the CPU Usage in Task-Manager. WMI plays very important role in getting these valuable information. But this is also required that WMI service should be running on the machine where you are running these commands.



Happy scripting!!