What does xargs do?

$ xargs -0 -I{} rm {}

• xargsbuild and run command lines from standard input
• -0input items are separated by NUL, not whitespace
• -I{}replace this token with each input item
• rmrun per input item: remove files or directories
• {}placeholder — each matched item is substituted here

$ xargs -n1 -P4 echo

• xargsbuild and run command lines from standard input
• -n1use at most this many arguments per command
• -P4run this many commands in parallel
• echorun per input item the "echo" command