One liners

sed

Replace all enters with spaces with sed.

sed ':a;N;$!ba;s/\n/ /g'

Replace all uppercase letters with lowercase with sed.

sed -e 's/\(.*\)/\L\1/'

The same with tr

tr '[:upper:]' '[:lower:]'

Get only the dashed mac addresses from a file

grep -o '..-..-..-..-..-..' file

Powershell

One liner powershell command to uninstall the application 'Linphone'.

C:\windows\system32\WindowsPowerShell\v1.0\powershell.exe -command "& {$app = Get-WmiObject -Class Win32_Product -Filter \"Name = 'Linphone'\"; $app.Uninstall() }"

Actually a two liner, but this is to put your computer to sleep after 60 seconds from the commandline. Note: hibernate should be turned off for this.

timeout 60
rundll32.exe powrprof.dll,SetSuspendState 0,1,0

Remove all files in the current directory older than 30 days.

forfiles /D -30 /C "cmd /C attrib -s @file & echo @file & del @file"

Clear all Windows Event Viewer logs.

wevtutil el | Foreach-Object {wevtutil cl “$_”}