1. Overview
To my understanding, PowerShell is more or less of a commandline shell which integrated with .Net framework. You can utilize a lot of objectsdefined in .Net Framework. You can access everything in COM or WMI, so that youcan control the services on local/remote machine.
PowerShell can execute 4 types of things:
- Regular command line commands, such as “cd”, “dir”,“copy”, in fact, those commands were just aliases to some .Net cmdlets, not theoriginal commands.
- Cmdlets: .Net programs designed to interact withPowerShell
- PowerShell scripts (.ps1 file)
- PowerShell functions
- Standalone executable
When execute something without relative/full path specified,PowerShell will look for the commands in this order:
- Alias
- Function
- Cmdlet
- Application
- Script
- files
To use PowerShell, you need to start PowerShell window oruse powershell.exe. When PowerShell window is started, by default, it loadssome libraries; you can import more libraries by edit PowerShell window profile.
When a PowerShell window is started, a windows script hostis created, $hostreference to the current host.
Output of execution will be one single value or array of variantvalues. The output can be the input of another executable by using “|” topipeline the commands.
Useful tip:
- Use get-help or helpor command -? wheneveris needed.
- PowerShell window support auto-finish-typing,use tab will automatically finish the word, more tab will switch among a listof satisfied choices.
- Use ` to continue with next line for command cross multi lines
Getgenuine PowerShell commands: Get-Command -commandType cmdlet
Use“&” to change astring to a command
- Use PowerShell window as calculator
- Decimal numbers: (23+7)/3.5 (Enter) , you will get 8.57142857142857
- Number with unit: 4GB/720MB(Enter) , you willget 5.68888888888889
- Convert 16-bit to decimal: “0xaf” will give you175.
- Trustworthy Subdirectories
- env: is currentenvironment
- Alias: has all the aliasdefined
- Function: has all the functions
- List all members in the subdirectory: Dir [name]: i.e. dir env: will list all the variables defined
2. Keyboard combination
Useful short-keycombinations:
| Key | Meaning |
| (Alt)+(F7) | Deletes the current command history |
| (PgUp), (PgDn) | Display the first (PgUp) or last (PgDn) command you used in current session |
| (Enter) | Send the entered lines to PowerShell for execution |
| (End) | Moves the editing cursor to the end of the command line |
| (Del) | Deletes the character to the right of the insertion point |
| (Esc) | Deletes current command line |
| (F2) | Moves in current command line to the next character corresponding to specified character |
| (F4) | Deletes all characters to the right of the insertion point up to specified character |
| (F7) | Displays last entered commands in a dialog box |
| (F8) | Displays commands from command history beginning with the character that you already entered in the command line |
| (F9) | Opens a dialog box in which you can enter the number of a command from your command history to return the command. (F7) displays numbers of commands in command history |
| (Left arrow), (Right arrow) | Move one character to the left or right respectively |
| (Arrow up), (Arrow down),(F5), (F8) | Repeat the last previously entered command |
| (Home) | Moves editing cursor to beginning of command line |
| (Backspace) | Deletes character to the left of the insertion point |
| (Ctrl)+(C) | Cancels command execution |
| (Ctrl)+(End) | Deletes all characters from current position to end of command line |
| (Ctrl)+(Arrow left), (Ctrl)+(Arrow right) | Move insertion point one word to the left or right respectively |
| (Ctrl)+(Home) | Deletes all characters of current position up to beginning of command line |
| (Tab) | Automatically completes current entry, if possible |
3. Cmdlet
Cmdlets arespecialized commands in the PowerShell environment that implement specificfunctions. Cmdlets follow a <verb>–<noun>namingpattern, such as Get-ChildItem, helping to make them self-descriptive.
A list of cmdletscould be saved in one ps1 file and execute them as a batch.
Make sure youhave enough privilege to execute all the cmdlets. Or you can change the host’sexecution policy by calling Set-ExecutionPolicy.
Most useful cmdlet: Get-Help, i.e. “get-helpget-*” will give you the list of cmdlets started with “get-“.
4. Parameter type:
- Fixed positioned
- Named
- Switch, turn on/off something, such as –Debug,-Verbose
- Value, a value must be provided, such as –WorkingDirectory[path]
5. Aliases
You can give commands other names.
- Define an alias: Set-Alias [alias] [command]
- Resolve an alias: $alias:[aliasname]
- remove an alias:
o by default, alias will be removed when you quit PowerShellwindow
o you can save the definition to an ps1 file and reloadit by calling “
o Del alias:[alias]
- List all available aliases: Dir alias:
- Reusealias definition by save the definition to a ps1 file
o Import-Alias [filename], with option [-Force] will force the alias to bereplaced if already exists.