pipe 命令用法

By far, the most useful and powerful thing youcan do with I/O redirection is to connect multiplecommands together with what are calledpipes. With pipes, the standard output ofone command is fed into the standard input ofanother. Here is my absolute favorite:

[me@linuxbox me]$ ls -l | less

In this example, the output of the ls command is fed into less. By using this"|less" trick, you can make any command havescrolling output. I use this technique all thetime.

By connecting commands together, you canacomplish amazing feats. Here are some examplesyou'll want to try:

Examples of commands used together with pipes

Command	What it does
ls -lt | head	Displays the 10 newest files in thecurrent directory.
du | sort-nr	Displays a list of directories and howmuch space they consume, sorted from thelargest to the smallest.
find . -type f-print |wc-l	Displays the total number of files in thecurrent working directory and all of itssubdirectories.