Several kinds of tasks occur repeatedly when working with text files.
You might want to extract certain lines and discard the rest. Or you
may need to make changes wherever certain patterns appear, but leave the
rest of the file alone. Such jobs are often easy with
awk utility interprets a special-purpose programming
language that makes it easy to handle simple data-reformatting jobs.
The GNU implementation of
awk is called
gawk; if you
invoke it with the proper options or environment variables,
it is fully compatible with
specification of the
and with the Unix version of
by Brian Kernighan.
This means that all
awk programs should work with
So most of the time, we don’t distinguish between
gawk and other
awk you can:
provides facilities that make it easy to:
This Web page teaches you about the
awk language and
how you can use it effectively. You should already be familiar with basic
system commands, such as
ls,2 as well as basic shell
facilities, such as input/output (I/O) redirection and pipes.
Implementations of the
awk language are available for many
different computing environments. This Web page, while describing
awk language in general, also describes the particular
gawk (which stands for
gawk runs on a broad range of Unix systems,
ranging from Intel-architecture PC-based computers
up through large-scale systems.
gawk has also been ported to Mac OS X,
(all versions) and OS/2 PCs,
|• History:||The history of |
|• Names:||What name to use to find |
|• This Manual:||Using this Web page. Includes sample input files that you can use.|
|• Conventions:||Typographical Conventions.|
|• Manual History:||Brief history of the GNU project and this Web page.|
|• How To Contribute:||Helping to save the world.|
The 2008 POSIX standard is accessible online at http://www.opengroup.org/onlinepubs/9699919799/.
These utilities are available on POSIX-compliant systems, as well as on traditional Unix-based systems. If you are using some other operating system, you still need to be familiar with the ideas of I/O redirection and pipes.
Some other, obsolete systems to which
was once ported are no longer supported and the code for those systems
has been removed.