_   /|
   U    ack!

ack 2.28 is a tool like grep, optimized for programmers

ack 3 is now in beta!

Designed for programmers with large heterogeneous trees of source code, ack is written purely in portable Perl 5 and takes advantage of the power of Perl's regular expressions.

Top 5 reasons to use ack

Blazing fast
It's fast because it only searches the stuff it makes sense to search.
Searches entire trees by default while ignoring Subversion, Git and other VCS directories and other files that aren't your source code.
Designed for code search
Where grep is a general text search tool, ack is especially for the programmer searching source code. Common tasks take fewer keystrokes.
Highly portable
ack is pure Perl, so it easily runs on a Windows installation Perl (like Strawberry Perl) without modifications.
Free and open
Ack costs nothing. It's 100% free and open source under Artistic License v2.0.
Want to contribute? Fork-us on !

Security alert

ack versions 2.00 to 2.11_02 are susceptible to a code execution exploit. Please upgrade to 2.12 or higher ASAP. See the security alert for more information.

How to install

ack is simple to install, via CPAN, package or simple download. Read how.

People love ack

"Every once in a while something comes along that improves an idea so much, you can't ignore it. Such a thing is Ack, the grep replacement."

Read what else people are saying.

Follow us on Twitter

We're all about knowing when to move beyond the stock Unix tools. Follow us on Twitter at @beyondgrep for tips, hints and software news.