Understanding the UNIX command xargs

Question

I\'m pretty much confused on this. Need some clarifications.

Example 1 :

pgrep string | xargs ps

Example 2 :

Answer 1

$ echo 'line1
> line2
> line3
> ...
> lineN ' | xargs cmd1 -a -b

will result in:

$ cmd1 -a -b line1 line2 line3 ... lineN

xargs will break cmd1 ... into several executions of cmd1 if the line count gets too large.

xargs may be used for many other tasks related to passing stdin lines as positional arguments. Take a look at the capital -P option in xargs(1) for running several instances of a command in parallel.