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| -rw-r--r-- | powershell.html.markdown | 96 |
1 files changed, 95 insertions, 1 deletions
diff --git a/powershell.html.markdown b/powershell.html.markdown index 2a7deee1..be802916 100644 --- a/powershell.html.markdown +++ b/powershell.html.markdown @@ -28,6 +28,18 @@ help about_Execution_Policies # for more info $PSVersionTable ``` +Getting help: +```powershell +# Find commands +Get-Command about_* # alias: gcm +Get-Command -Verb Add +Get-Alias ps +Get-Alias -Definition Get-Process + +Get-Help ps | less # alias: help +ps | Get-Member # alias: gm +``` + The tutorial starts here: ```powershell # As you already figured, comments start with # @@ -44,8 +56,10 @@ echo 'This is the first line'; echo 'This is the second line' $aString="Some string" # Or like this: $aNumber = 5 +$aList = 1,2,3,4,5 +$aHashtable = @{name1='val1'; name2='val2'} -# Using the variable: +# Using variables: echo $aString echo "Interpolation: $aString" echo "`$aString has length of $($aString.length)" @@ -78,7 +92,87 @@ $Name = Read-Host "What's your name?" echo "Hello, $Name!" [int]$Age = Read-Host "What's your age?" +# Control Flow +# We have the usual if structure: +if ($Age -is [string]) { + echo 'But.. $Age cannot be a string!' +} elseif ($Age -lt 12 -and $Age -gt 0) { + echo 'Child (Less than 12. Greater than 0)' +} else { + echo 'Adult' +} +# Switch statements are more powerfull compared to most languages +$val = "20" +switch($val) { + { $_ -eq 42 } { "The answer equals 42"; break } + '20' { "Exactly 20"; break } + { $_ -like 's*' } { "Case insensitive"; break } + { $_ -clike 's*'} { "clike, ceq, cne for case sensitive"; break } + { $_ -notmatch '^.*$'} { "Regex matching. cnotmatch, cnotlike, ..."; break } + { 'x' -contains 'x'} { "FALSE! -contains is for lists!"; break } + default { "Others" } +} + +# The classic for +for($i = 1; $i -le 10; $i++) { + "Loop number $i" +} +# Or shorter +1..10 | % { "Loop number $_" } + +# PowerShell also offers +foreach ($var in 'val1','val2','val3') { echo $var } +# while () {} +# do {} while () +# do {} until () + + +# List files and directories in the current directory +ls # or `dir` +cd ~ # goto home + +Get-Alias ls # -> Get-ChildItem +# Uh!? These cmdlets have generic names because unlike other scripting +# languages, PowerShell does not only operate in the current directory. +cd HKCU: # go to the HKEY_CURRENT_USER registry hive + +# Get all providers in your session +Get-PSProvider + +# Cmdlets have parameters that control their execution: +Get-ChildItem -Filter *.txt -Name # Get just the name of all txt files +# Only need to type as much of a parameter name until it is no longer ambiguous +ls -fi *.txt -n # -f is not possible because -Force also exists +# Use `Get-Help Get-ChildItem -Full` for a complete overview + +# Results of the previous cmdlet can be passed to the next as input. +# grep cmdlet filters the input with provided patterns. +# `$_` is the current object in the pipeline object. +ls | Where-Object { $_.Name -match 'c' } | Export-CSV export.txt +ls | ? { $_.Name -match 'c' } | ConvertTo-HTML | Out-File export.html + +# If you get confused in the pipeline use `Get-Member` for an overview +# of the available methods and properties of the pipelined objects: +ls | Get-Member +Get-Date | gm + +# ` is the line continuation character. Or end the line with a | +Get-Process | Sort-Object ID -Descending | Select-Object -First 10 Name,ID,VM ` + | Stop-Process -WhatIf + +Get-EventLog Application -After (Get-Date).AddHours(-2) | Format-List + +# Use % as a shorthand for ForEach-Object +(a,b,c) | ForEach-Object ` + -Begin { "Starting"; $counter = 0 } ` + -Process { "Processing $_"; $counter++ } ` + -End { "Finishing: $counter" } + +# Get-Process as a table with three columns +# The third column is the value of the VM property in MB and 2 decimal places +# Computed columns can be written more succinctly as: `@{n='lbl';e={$_}` +ps | Format-Table ID,Name,@{name='VM(MB)';expression={'{0:n2}' -f ($_.VM / 1MB)}} -autoSize ``` |