The Silver Searcher

A code searching tool similar to ack, with a focus on speed.

Do you know C? Want to improve ag? I invite you to pair with me.

What’s so great about Ag?

It is an order of magnitude faster than ack.
It ignores file patterns from your .gitignore and .hgignore.
If there are files in your source repo you don’t want to search, just add their patterns to a .ignore file. (*cough* *.min.js *cough*)
The command name is 33% shorter than ack, and all keys are on the home row!

Ag is quite stable now. Most changes are new features, minor bug fixes, or performance improvements. It’s much faster than Ack in my benchmarks:

ack test_blah ~/code/  104.66s user 4.82s system 99% cpu 1:50.03 total

ag test_blah ~/code/  4.67s user 4.58s system 286% cpu 3.227 total

Ack and Ag found the same results, but Ag was 34x faster (3.2 seconds vs 110 seconds). My ~/code directory is about 8GB. Thanks to git/hg/ignore, Ag only searched 700MB of that.

There are also graphs of performance across releases.

How is it so fast?

Ag uses Pthreads to take advantage of multiple CPU cores and search files in parallel.
Files are mmap()ed instead of read into a buffer.
Literal string searching uses Boyer-Moore strstr.
Regex searching uses PCRE’s JIT compiler (if Ag is built with PCRE >=8.21).
Ag calls pcre_study() before executing the same regex on every file.
Instead of calling fnmatch() on every pattern in your ignore files, non-regex patterns are loaded into arrays and binary searched.

I’ve written several blog posts showing how I’ve improved performance. These include how I added pthreads, wrote my own scandir(), benchmarked every revision to find performance regressions, and profiled with gprof and Valgrind.

Installing

macOS

brew install the_silver_searcher

port install the_silver_searcher

Linux

Ubuntu >= 13.10 (Saucy) or Debian >= 8 (Jessie)
```
  apt-get install silversearcher-ag
```
Fedora 21 and lower
```
  yum install the_silver_searcher
```
Fedora 22+
```
  dnf install the_silver_searcher
```

RHEL7+

  yum install epel-release.noarch the_silver_searcher

Gentoo

  emerge -a sys-apps/the_silver_searcher

Arch
```
  pacman -S the_silver_searcher
```
Slackware
```
  sbopkg -i the_silver_searcher
```
openSUSE
```
  zypper install the_silver_searcher
```
CentOS
```
  yum install the_silver_searcher
```
NixOS/Nix/Nixpkgs
```
  nix-env -iA silver-searcher
```
SUSE Linux Enterprise: Follow these simple instructions.

BSD

FreeBSD
```
  pkg install the_silver_searcher
```
OpenBSD/NetBSD
```
  pkg_add the_silver_searcher
```

Windows

Win32/64

Unofficial daily builds are available.
winget
```
  winget install "The Silver Searcher"
```
Notes:
- This installs a release of ag.exe optimized for Windows.
- winget is intended to become the default package manager client for Windows.
  As of June 2020, it’s still in beta, and can be installed using instructions there.
- The setup script in the Ag’s winget package installs ag.exe in the first directory that matches one of these criteria:
  1. Over a previous instance of ag.exe from the same origin found in the PATH
  2. In the directory defined in environment variable bindir_%PROCESSOR_ARCHITECTURE%
  3. In the directory defined in environment variable bindir
  4. In the directory defined in environment variable windir
Chocolatey
```
  choco install ag
```
MSYS2
```
  pacman -S mingw-w64-{i686,x86_64}-ag
```
Cygwin

Run the relevant setup-*.exe, and select “the_silver_searcher” in the “Utils” category.

Building from source

Building master

Install dependencies (Automake, pkg-config, PCRE, LZMA):

macOS:

  brew install automake pkg-config pcre xz

  port install automake pkgconfig pcre xz

Ubuntu/Debian:

  apt-get install -y automake pkg-config libpcre3-dev zlib1g-dev liblzma-dev

Fedora:

  yum -y install pkgconfig automake gcc zlib-devel pcre-devel xz-devel

CentOS:

  yum -y groupinstall "Development Tools"
  yum -y install pcre-devel xz-devel zlib-devel

openSUSE:

  zypper source-install --build-deps-only the_silver_searcher

Windows: It’s complicated. See this wiki page.

Run the build script (which just runs aclocal, automake, etc):
```
 ./build.sh
```
On Windows (inside an msys/MinGW shell):
```
 make -f Makefile.w32
```
Make install:
```
 sudo make install
```

Building a release tarball

GPG-signed releases are available here.

Building release tarballs requires the same dependencies, except for automake and pkg-config. Once you’ve installed the dependencies, just run:

./configure
make
make install

You may need to use sudo or run as root for the make install.

Editor Integration

Vim

You can use Ag with ack.vim by adding the following line to your .vimrc:

let g:ackprg = 'ag --nogroup --nocolor --column'

or:

let g:ackprg = 'ag --vimgrep'

Which has the same effect but will report every match on the line.

Emacs

You can use ag.el as an Emacs front-end to Ag. See also: helm-ag.

TextMate

TextMate users can use Ag with my fork of the popular AckMate plugin, which lets you use both Ack and Ag for searching. If you already have AckMate you just want to replace Ack with Ag, move or delete "~/Library/Application Support/TextMate/PlugIns/AckMate.tmplugin/Contents/Resources/ackmate_ack" and run ln -s /usr/local/bin/ag "~/Library/Application Support/TextMate/PlugIns/AckMate.tmplugin/Contents/Resources/ackmate_ack"

Other stuff you might like

Ack - Better than grep. Without Ack, Ag would not exist.
ack.vim
Exuberant Ctags - Faster than Ag, but it builds an index beforehand. Good for really big codebases.
Git-grep - As fast as Ag but only works on git repos.
fzf - A command-line fuzzy finder
ripgrep
Sack - A utility that wraps Ack and Ag. It removes a lot of repetition from searching and opening matching files.