Slackware Linux Essentials
Prev	Chapter 10 Handling Files and -Directories	Next

10.3 Simple -Output: `cat` and `echo`

- -

10.3.1 `cat`

- -

cat(1) is short for “concatenate”. It was -originally designed to merge text files into one, but can be used for many other -purposes.

- -

To merge two or more files into one, you simply list the files after the cat command and then redirect the new output to a file. cat works with standard input and standard output, so you have to -use the shell redirection characters. For example:

- - - - - -

-% cat file1 file2 file3 > bigfile
-

- -

This command takes the contents of file1, file2, and file3 and merges it all -together. The new output is sent to standard out.

- -

One can also use cat to display files. Many people cat text files through the more or less commands, like this:

- - - - - -

-% cat file1 | more
-

- -

That will display the file1 file and pipe it through the more command so that you only get one screen at a time.

- -

Another common use for cat is copying files. You can copy any -file around with cat, like this:

- - - - - -

-% cat /bin/bash > ~/mybash
-

- -

The /bin/bash program is copied to your home directory and -named mybash.

- -

cat has many uses and the ones discussed here are just a few. -Since cat makes extensive use of standard input and standard -output, it is ideal for use in shell scripts or part of other complex commands.

- -

10.3.2 `echo`

- -

The echo(1) command displays the specified text on the -screen. You specify the string to display after the echo -command. By default echo will display the string and print a -newline character after it. You can pass the -n option to -suppress the printing of the newline. The -e option will cause -echo to search for escape characters in the string and execute -them.

Prev	Home	Next
Pagers: `more`, `less`, and `most`	Up	Creation: `touch` and -`mkdir`

10.3 Simple -Output: cat and echo

10.3.1 cat

10.3.2 echo

10.3 Simple -Output: `cat` and `echo`

10.3.1 `cat`

10.3.2 `echo`