Search notes:

ack

ack is a grep like tool, optimized for programmers.
Apparently, ack is installed on Ubuntu with sudo apt-get install ack-grep.

Interesting flags

-i: Ignore case
-l: Print filename if match found
--ignore-dir=DIR and --noignore-dir=DIR: ignore or add directories to search
--type=TYPE: Search for file type (for example if TYPE is cpp, it searches *.cpp .cc .cxx .m .hpp .hh .h .hxx*, see ack --help-types for more details)

Installing

cpan App::Ack
or, on Windows: 
perl -MCPAN -e "CPAN::Shell->force(qw(install App::Ack));"
On Arch linux: 
sudo pacman -S ack

See also

Perl module App::Ack
tools

Links

beyondgrep.com
A similar tool to ack, but with focus on speed is The Silver Searcher.
ack.vim: to run ack from vim.
Exuberant Ctags is faster than anything because it builds an index. Useful for large codebases.
git-grep to work on Git repositories.
The platinum searcher. Apparently written in go.
sack

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