Sams Teach Yourself Shell Programming in 24 Hours, Second Edition

xargs

xargs is a command that accepts a list of words from standard input and provides those words as arguments to a given command:

cat filelist | xargs rm

You cannot pipe the output of cat directly to rm because rm does not look for filenames on standard input. xargs reads the files being passed by cat and builds up a command line beginning with rm and ending with the filenames. If there are a large number of files, xargs runs the rm command multiple times, deleting some of the files each time. You can specify how many arguments from standard input to build up on the command line with the -n option:

cat filelist | xargs -n 20 rm

-n 20 says to put only 20 arguments on each command line, so you delete only 20 files at a time. Here is a different ...