Windows

When a batch file modifies an environment variable, cmd.exe retains this change even after the script exits. This often causes problems, as one batch file can accidentally pollute the environment of another. That said, batch file authors sometimes intentionally change the global environment to customize the path and other aspects of the environment to suit a specific task.

Problem

You want to invoke a PowerShell script from a batch file, a logon script, scheduled task, or any other nonPowerShell application.

Solution

Launch PowerShell.exe in the following way:

PowerShell "& 'full path to script' arguments"

For example,

PowerShell "& 'c:\shared scripts\GetReport.ps1' Hello World"

Discussion

Both the GetCommand and GetHelp cmdlets let you search for command names that match a given pattern. However, when you don’t know exactly what portions of a command name you are looking for, you will more often have success searching through the help content for an answer. On Unix systems, this command is called Apropos. Similar functionality does not exist as part of the PowerShell’s help facilities, however.

That doesn’t need to stop us, though, as we can write the functionality ourselves.

Problem

You want to learn about how a specific command works and how to use it.

Solution

The command that provides help and usage information about a command is called GetHelp. It supports several different views of the help information, depending on your needs.

To get the summary of help information for a specific command, provide the command’s name as an argument to the GetHelp cmdlet. This primarily includes its synopsis, syntax, and detailed description:

GetHelp CommandName

or

Problem

You want to accomplish a task in PowerShell but don’t know the command or cmdlet to accomplish that task.

Solution

Use the GetCommand cmdlet to search for and investigate commands.

To get the summary information about a specific command, specify the command name as an argument:

Problem

You want to customize PowerShell’s interactive experience with a personalized prompt, aliases, and more.

Solution

When you want to customize aspects of PowerShell, place those customizations in your personal profile script. PowerShell provides easy access to this profile script by storing its location in the $profile variable.

By default, PowerShell’s security policies prevent scripts (including your profile) from running. Once you begin writing scripts, though, you should configure this policy to something less restrictive.

Problem

You want to run a PowerShell command.

Solution

To run a PowerShell command, type its name at the command prompt. For example:

PS >GetProcess

Handles NPM(K) PM(K) WS(K) VM(M) CPU(s) Id ProcessName

133 5 11760 7668 46 1112 audiodg

184 5 33248 508 93 1692 avgamsvr

143 7 31852 984 97 1788 avgemc

Discussion

The GetProcess command is an example of a native PowerShell command, called a cmdlet. As compared to traditional commands, cmdlets provide significant benefits to both administrators and developers:

Problem

You rely on a lot of effort invested in your current tools. You have traditional executables, Perl scripts, VBScript, and of course, a legacy build system that has organically grown into a tangled mess of batch files. You want to use PowerShell, but don’t want to give up everything you already have.

Solution

To run a program, script, batch file, or other executable command in the system’s path, enter its filename. For these executable types, the extension is optional:

Program.exe arguments ScriptName.ps1 arguments BatchFile.cmd arguments

Above all else, the design of Windows PowerShell places priority on its use as an efficient and powerful interactive shell. Even its scripting language plays a critical role in this effort, as it too heavily favors interactive use.