Mastery of PowerShell
By Jean-Claude Colette
Apr 20, 2016
Description:
Here we present the essential commands of the PowerShell and give some examples of using a few commands.
Essential commands
|
File and path manipulation
|
|
Cmdlet name
|
Command alias
|
Description
|
|
Get-ChildItem
|
gci,
dir, ls
|
Lists
current directory content
|
|
Get-Location
|
gl, pwd
|
Shows
the current directory
|
|
Set-Location
|
sl, cd,
chdir
|
Changes
directory
|
|
tree
|
tree
|
Displays
the directory structure
|
|
Push-Location
|
pushd
|
Saves
the current directory on the stack and changes directory to the one given as
argument
|
|
Pop-Location
|
popd
|
Pops the
name on the stack and changes directory to it
|
|
Copy-Item
|
cpi,
copy, cp
|
Deletes
a folder with confirmation
|
|
Rename-Item
|
rni, ren
|
Renames
an item
|
|
md
|
mkdir
|
Creates
a new directory
|
|
Remove-Item
|
ri, del,
erase, rmdir, rd, rm
|
Removes
files or directories
|
|
Move-Item
|
mi,
move, mv
|
Moves or
renames files
|
|
Get-Content
|
Gc,type,cat
|
Displays
file content on the stdout
|
|
New-Item
|
ni
|
Creates a new item
|
|
System
|
|
Cmdlet name
|
Command alias
|
Description
|
|
Clear-Host
|
cls,
clear
|
Clears
the display
|
|
Get-Help
|
help,
man
|
Gets
help on a command or a topic
|
|
Set-Variable
|
set, sv
|
Sets the value of a variable
|
|
Get-PSDrive
|
gdr
|
Shows the drives
|
|
Write-Output
|
echo,
write
|
Print to
standard output
|
|
Processes
|
|
Cmdlet name
|
Command alias
|
Description
|
|
Get-Process
|
gps, ps
|
Shows running processes
|
|
Stop-Process
|
spps, kill
|
Stop a running process
|
|
Measure-Command
|
|
Gets the execution time of a command or script
|
|
Strings
|
|
String comparison
|
|
Command
|
Description
|
|
-eq -ceq
|
Returns True or False according to whether
the strings on both sides of the operator are equal. -ceq is case-sensitive
|
|
-ne -cne
|
Returns True or False according to whether
the strings on both sides of the operator are different. -cne is
case-sensitive
|
|
-ge -cge
|
Greater than or equal
|
|
-gt -cgt
|
Greater than
|
|
-lt -clt
|
Less than
|
|
-le -cle
|
Less than or equal
|
|
-Like -CLike
|
Wildcard comparison
|
|
-NotLike -CNotLike
|
|
|
-Match -CMatch
|
Regular expression comparison
|
|
-NotMatch -CNotMatch
|
|
|
String manipulation
|
|
Command
|
Description
|
|
string.TrimStart("string_to_remove")
|
Removes the specified string from the
beginning of the string
|
|
string.TrimEnd("string_to_remove")
|
Removes the specified string from the end
of the string
|
|
-replace
|
|
|
Escape characters in string
|
|
Escape character
|
Effect
|
|
`n
|
New line
|
|
`r
|
Carriage Return
|
|
`t
|
Tab
|
|
`a
|
Alert
|
|
`b
|
Backspace
|
|
`'
|
Single Quote
|
|
`"
|
Double Quote
|
|
``
|
Back quote
|
|
`0
|
Null
|
|
Control
structures
|
|
Instruction
|
Description
|
if (condition) {
#codeblock
}
|
Executes a block of code if a certain
condition is True
|
if (condition) {
#codeblock
}
elseif (condition) {
#codeblock
}
else {
#codeblock
}
|
Complete schemas of the if-elseif-else
compound statement
|
$i = 0
while ($i -le 100) {
echo $i
$i++
}
|
Prints integers from 0 to 100
|
for ($i=0; $i -lt 10; $i++) {
echo $i
}
|
Prints integers from 0 to 9
|
foreach ($i in $array) {
#codeblock
}
|
Loops through all the objects in an array
|
|
continue
|
Skips the current loop iteration and
begins the next
|
|
break
|
Exits the current loop iteration
|
|
|
|
function MyFunc {
param ($p1)
echo $p1
}
|
Declares a function with one parameter
|
Creating text files
Creating new files
Empty file
To create an empty file, you can use the
command ni (New-Item):
or
ni FileName.ext -ItemType "file"
The created file is 0 bytes.
Text file
You can create an empty text file with the
redirection operator:
or
$null | Out-File FileName.txt
The file subsequently created is in Unicode
format. With Out-File you can create an empty file in another encoding.
$null | Out-File -Encoding "UTF8" FileName.txt
Showing file content
To get the contents of a file, we use the get-content command or one of its aliases gc, type, cat.
Suppose the file
pwd.ini contains:
Type
The output:
- [passwords]
- CESAMEopen
- WalkInTheShadows
Showing n lines of a file
Consider the following file:
file1.txt:
gc -totalcount 2 file1.txt
Merging text files
Consider the following two files:
file1.txt:
file2.txt:
To merge the two files, we can copy the first file on
file3.txt and use
Add-Content:
copy file1.txt file3.txt
gc .\file2.txt | Add-Content .\file3.txt
It is possible to use the redirection operator >>, to merge files:
copy file1.txt file3.txt
gc .\file2.txt >> file3.txt
Warning! The redirection operator >> does not retain the encoding of the original file and works by default with Unicode.
Comparing file content
To compare two objects in PowerShell, use
the command: Compare-Object with
Here is the full syntax:
compare-object -referenceobject $(get-content C:\test\testfile1.txt) -differenceobject $(get-content C:\test\testfile2.txt)
Compare (type file1.txt) (type file2.txt)
