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 Different in this Fork?

• Requires libpcre2, pcre version 1 is no longer supported
• Support for a .agrc file which may contain arbitrary options, one per line. Default is ~/.agrc, and can be set with --agrc=<file> on the command line
• Various memory leaks fixed, plus a script for testing with LLVM Sanitizers
• Various cosmetic and usability tweaks

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

or

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
  

• 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.

• 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

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

   • macOS:

       brew install automake pkg-config pcre xz
     

     or

       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.

2. Run the build script (which just runs aclocal, automake, etc):

    ./build.sh
   

   On Windows (inside an msys/MinGW shell):

    make -f Makefile.w32
   

3. Make install:

    sudo make install
   

Build options

• As you'd expect, run ./configure --help to get a list of all available autoconf options.
• --enable-zlib / --disable-zlib: force enabling or disable gzip decompression support when running ag -z, the default is to auto-detect. Requires the zlib library (zlib1g-dev package on Ubuntu/Debian)
• --enable-lzma / --disable-lzma: force enabling or disable LZMA (xz) decompression support when running ag -z, the default is to auto-detect. Requires the lzma library (liblzma-dev package on Ubuntu/Debian)
• --enable-libarchive: Use libarchive to decompress a wide variety of compression formats. Requires the libarchive library.
  • Warning: while flexible, the libarchive format detection is slow compared to the built-in gz/xz checks, and may significantly slow down ag if searching directories containing lots of uncompressed files (only when using the -z option)

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.
• ripgrep
• Sack - A utility that wraps Ack and Ag. It removes a lot of repetition from searching and opening matching files.