PowerShell

run

single command

powershell -c "$lastmonth = (Get-Date).addMonths(-3); $lastmonth.tostring(\"yyyy-MM\")"

script file

powershell -executionpolicy bypass -File ./del-old-dirs.ps1

echo/print

Write-Host "Hello World"
pause

date

get current date e.g. YYYY-MM

powershell -c "$lastmonth = (Get-Date).addMonths(-3); $lastmonth.tostring(\"yyyy-MM\")"

strings

get substring of string

$var = 'Hello World'
$result = $var.substring(0, 5)
$result-> Hello

merge stings

$dest = $rootPath + "\" +$subFolder

filesystem access

check a dir exists

if (Test-Path $dest) { ... }

del / delete file

Remove-Item -Path "C:\dir\file.txt" 

mkdir / create dirctory

New-Item -ItemType directory -Path C:\newDir

select old files from directory

$limit = (Get-Date).AddDays(-90)
$scope = Get-ChildItem -Path $dir -Force | Where-Object { $_.PSIsContainer -and $_.CreationTime -lt $limit }
#
# Filters:
# -Filter "*.dfq"
# Where
# $_.PSIsContainer  => dirs
# !$_.PSIsContainer => files
# 
# write scope to CSV file
$scope | Select-Object FullName, CreationTime | Export-Csv -Path .\$logfile -NoTypeInformation 
# -Append 
# delete files in scope
$scope | Remove-Item -Force

delete old files

delete old files (from [1])

$limit = (Get-Date).AddDays(-15)
$path = "C:\Some\Path"
# delete files older than the $limit.
Get-ChildItem -Path $path -Recurse -Force | Where-Object { !$_.PSIsContainer -and $_.CreationTime -lt $limit } | Remove-Item -Force 
# delete any empty directories left behind after deleting the old files.
Get-ChildItem -Path $path -Recurse -Force | Where-Object { $_.PSIsContainer -and (Get-ChildItem -Path $_.FullName -Recurse -Force | Where-Object { !$_.PSIsContainer }) -eq $null } | Remove-Item -Force -Recurse

if / else

if folder exists

if (Test-Path $dirDone) { ... }

exit with error code

exit (1)

loops

$dirs = Get-ChildItem -Path .\ -Directory
foreach ($d in $dirs) { ... }

mount network share

net use q: \\server\dir1\dir2
net use q: /delete