ripgrep/FAQ.md

FAQ

• Does ripgrep support configuration files?
• What's changed in ripgrep recently?
• When is the next release?
• Does ripgrep have a man page?
• Does ripgrep have support for shell auto-completion?
• How do I use lookaround and/or backreferences?
• How do I configure ripgrep's colors?
• How do I enable true colors on Windows?
• How do I stop ripgrep from messing up colors when I kill it?
• How can I get results in a consistent order?
• How do I search files that aren't UTF-8?
• How do I search compressed files?
• How do I search over multiple lines?
• How do I get around the regex size limit?
• How do I make the -f/--file flag faster?
• How do I make the output look like The Silver Searcher's output?
• When I run rg, why does it execute some other command?
• How do I create an alias for ripgrep on Windows?
• How do I create a PowerShell profile?
• How do I pipe non-ASCII content to ripgrep on Windows?
• How is ripgrep licensed?
• Can ripgrep replace grep?
• What does the "rip" in ripgrep mean?

Does ripgrep support configuration files?

Yes. See the guide's section on configuration files.

What's changed in ripgrep recently?

Please consult ripgrep's CHANGELOG.

When is the next release?

ripgrep is a project whose contributors are volunteers. A release schedule adds undue stress to said volunteers. Therefore, releases are made on a best effort basis and no dates will ever be given.

One exception to this is high impact bugs. If a ripgrep release contains a significant regression, then there will generally be a strong push to get a patch release out with a fix.

Does ripgrep have a man page?

Yes! Whenever ripgrep is compiled on a system with asciidoc present, then a man page is generated from ripgrep's argv parser. After compiling ripgrep, you can find the man page like so from the root of the repository:

$ find ./target -name rg.1 -print0 | xargs -0 ls -t | head -n1
./target/debug/build/ripgrep-79899d0edd4129ca/out/rg.1

Running man -l ./target/debug/build/ripgrep-79899d0edd4129ca/out/rg.1 will show the man page in your normal pager.

Note that the man page's documentation for options is equivalent to the output shown in rg --help. To see more condensed documentation (one line per flag), run rg -h.

The man page is also included in all ripgrep binary releases.

Does ripgrep have support for shell auto-completion?

Yes! Shell completions can be found in the same directory as the man page after building ripgrep. Zsh completions are maintained separately and committed to the repository in complete/_rg.

Shell completions are also included in all ripgrep binary releases.

For bash, move rg.bash to $XDG_CONFIG_HOME/bash_completion or /etc/bash_completion.d/.

For fish, move rg.fish to $HOME/.config/fish/completions/.

For zsh, move _rg to one of your $fpath directories.

For PowerShell, add . _rg.ps1 to your PowerShell profile (note the leading period). If the _rg.ps1 file is not on your PATH, do . /path/to/_rg.ps1 instead.

How can I get results in a consistent order?

By default, ripgrep uses parallelism to execute its search because this makes the search much faster on most modern systems. This in turn means that ripgrep has a non-deterministic aspect to it, since the interleaving of threads during the execution of the program is itself non-deterministic. This has the effect of printing results in a somewhat arbitrary order, and this order can change from run to run of ripgrep.

The only way to make the order of results consistent is to ask ripgrep to sort the output. Currently, this will disable all parallelism. (On smaller repositories, you might not notice much of a performance difference!) You can achieve this with the --sort-files flag.

There is more discussion on this topic here: https://github.com/BurntSushi/ripgrep/issues/152

How do I search files that aren't UTF-8?

See the guide's section on file encoding.

How do I search compressed files?

ripgrep's -z/--search-zip flag will cause it to search compressed files automatically. Currently, this supports gzip, bzip2, lzma and xz only and requires the corresponding gzip, bzip2 and xz binaries to be installed on your system. (That is, ripgrep does decompression by shelling out to another process.)

ripgrep currently does not search archive formats, so *.tar.gz files, for example, are skipped.

How do I search over multiple lines?

This isn't currently possible. ripgrep is fundamentally a line-oriented search tool. With that said, multiline search is a planned opt-in feature.

How do I use lookaround and/or backreferences?

This isn't currently possible. ripgrep uses finite automata to implement regular expression search, and in turn, guarantees linear time searching on all inputs. It is difficult to efficiently support lookaround and backreferences in finite automata engines, so ripgrep does not provide these features.

If a production quality regular expression engine with these features is ever written in Rust, then it is possible ripgrep will provide it as an opt-in feature.

How do I configure ripgrep's colors?

ripgrep has two flags related to colors:

• --color controls when to use colors.
• --colors controls which colors to use.

The --color flag accepts one of the following possible values: never, auto, always or ansi. The auto value is the default and will cause ripgrep to only enable colors when it is printing to a terminal. But if you pipe ripgrep to a file or some other process, then it will suppress colors.

The --colors` flag is a bit more complicated. The general format is:

--colors '{type}:{attribute}:{value}'

• {type} should be one of path, line, column or match. Each of these correspond to the four different types of things that ripgrep will add color to in its output. Select the type whose color you want to change.
• {attribute} should be one of fg, bg or style, corresponding to foreground color, background color, or miscellaneous styling (such as whether to bold the output or not).
• {value} is determined by the value of {attribute}. If {attribute} is style, then {value} should be one of nobold, bold, nointense, intense, nounderline or underline. If {attribute} is fg or bg, then {value} should be a color.

A color is specified by either one of eight of English names, a single 256-bit number or an RGB triple (with over 16 million possible values, or "true color").

The color names are red, blue, green, cyan, magenta, yellow, white or black.

A single 256-bit number is a value in the range 0-255 (inclusive). It can either be in decimal format (e.g., 62) or hexadecimal format (e.g., 0x3E).

An RGB triple corresponds to three numbers (decimal or hexadecimal) separated by commas.

As a special case, --colors '{type}:none' will clear all colors and styles associated with {type}, which lets you start with a clean slate (instead of building on top of ripgrep's default color settings).

Here's an example that makes highlights the matches with a nice blue background with bolded white text:

$ rg somepattern \
    --colors 'match:none' \
    --colors 'match:bg:0x33,0x66,0xFF' \
    --colors 'match:fg:white' \
    --colors 'match:style:bold'

Colors are an ideal candidate to set in your configuration file. See the question on emulating The Silver Searcher's output style for an example specific to colors.

How do I enable true colors on Windows?

First, see the previous question's answer on configuring colors.

Secondly, coloring on Windows is a bit complicated. If you're using a terminal like Cygwin, then it's likely true color support already works out of the box. However, if you are using a normal Windows console (cmd or PowerShell) and a version of Windows prior to 10, then there is no known way to get true color support. If you are on Windows 10 and using a Windows console, then true colors should work out of the box with one caveat: you might need to clear ripgrep's default color settings first. That is, instead of this:

$ rg somepattern --colors 'match:fg:0x33,0x66,0xFF'

you should do this

$ rg somepattern --colors 'match:none' --colors 'match:fg:0x33,0x66,0xFF'

This is because ripgrep might set the default style for match to bold, and it seems like Windows 10's VT100 support doesn't permit bold and true color ANSI escapes to be used simultaneously. The work-around above will clear ripgrep's default styling, allowing you to craft it exactly as desired.

How do I stop ripgrep from messing up colors when I kill it?

Type in color in cmd.exe (Command Prompt) and echo -ne "\033[0m" on Unix-like systems to restore your original foreground color.

In PowerShell, you can add the following code to your profile which will restore the original foreground color when Reset-ForegroundColor is called. Including the Set-Alias line will allow you to call it with simply color.

$OrigFgColor = $Host.UI.RawUI.ForegroundColor
function Reset-ForegroundColor {
	$Host.UI.RawUI.ForegroundColor = $OrigFgColor
}
Set-Alias -Name color -Value Reset-ForegroundColor

PR #187 fixed this, and it was later deprecated in #281. A full explanation is available here.

How do I get around the regex size limit?

If you've given ripgrep a particularly large pattern (or a large number of smaller patterns), then it is possible that it will fail to compile because it hit a pre-set limit. For example:

$ rg '\pL{1000}'
Compiled regex exceeds size limit of 10485760 bytes.

(Note: \pL{1000} may look small, but \pL is the character class containing all Unicode letters, which is quite large. And it's repeated 1000 times.)

In this case, you can work around by simply increasing the limit:

$ rg '\pL{1000}' --regex-size-limit 1G

Increasing the limit to 1GB does not necessarily mean that ripgrep will use that much memory. The limit just says that it's allowed to (approximately) use that much memory for constructing the regular expression.

How do I make the -f/--file flag faster?

The -f/--file permits one to give a file to ripgrep which contains a pattern on each line. ripgrep will then report any line that matches any of the patterns.

If this pattern file gets too big, then it is possible ripgrep will slow down dramatically. Typically this is because an internal cache is too small, and will cause ripgrep to spill over to a slower but more robust regular expression engine. If this is indeed the problem, then it is possible to increase this cache and regain speed. The cache can be controlled via the --dfa-size-limit flag. For example, using --dfa-size-limit 1G will set the cache size to 1GB. (Note that this doesn't mean ripgrep will use 1GB of memory automatically, but it will allow the regex engine to if it needs to.)

How do I make the output look like The Silver Searcher's output?

Use the --colors flag, like so:

rg --colors line:fg:yellow      \
   --colors line:style:bold     \
   --colors path:fg:green       \
   --colors path:style:bold     \
   --colors match:fg:black      \
   --colors match:bg:yellow     \
   --colors match:style:nobold  \
   foo

Alternatively, add your color configuration to your ripgrep config file (which is activated by setting the RIPGREP_CONFIG_PATH environment variable to point to your config file). For example:

$ cat $HOME/.config/ripgrep/rc
--colors=line:fg:yellow
--colors=line:style:bold
--colors=path:fg:green
--colors=path:style:bold
--colors=match:fg:black
--colors=match:bg:yellow
--colors=match:style:nobold
$ RIPGREP_CONFIG_PATH=$HOME/.config/ripgrep/rc rg foo

When I run rg, why does it execute some other command?

It's likely that you have a shell alias or even another tool called rg which is interfering with ripgrep. Run which rg to see what it is.

(Notably, the Rails plug-in for Oh My Zsh sets up an rg alias for rails generate.)

Problems like this can be resolved in one of several ways:

• If you're using the OMZ Rails plug-in, disable it by editing the plugins array in your zsh configuration.
• Temporarily bypass an existing rg alias by calling ripgrep as command rg, \rg, or 'rg'.
• Temporarily bypass an existing alias or another tool named rg by calling ripgrep by its full path (e.g., /usr/bin/rg or /usr/local/bin/rg).
• Permanently disable an existing rg alias by adding unalias rg to the bottom of your shell configuration file (e.g., .bash_profile or .zshrc).
• Give ripgrep its own alias that doesn't conflict with other tools/aliases by adding a line like the following to the bottom of your shell configuration file: alias ripgrep='command rg'.

How do I create an alias for ripgrep on Windows?

Often you can find a need to make alias for commands you use a lot that set certain flags. But PowerShell function aliases do not behave like your typical linux shell alias. You always need to propagate arguments and stdin input. But it cannot be done simply as function grep() { $input | rg.exe --hidden $args }

Use below example as reference to how setup alias in PowerShell.

function grep {
    $count = @($input).Count
    $input.Reset()

    if ($count) {
        $input | rg.exe --hidden $args
    }
    else {
        rg.exe --hidden $args
    }
}

PowerShell special variables:

• input - is powershell stdin object that allows you to access its content.
• args - is array of arguments passed to this function.

This alias checks whether there is stdin input and propagates only if there is some lines. Otherwise empty $input will make powershell to trigger rg to search empty stdin.

How do I create a PowerShell profile?

To customize powershell on start-up, there is a special PowerShell script that has to be created. In order to find its location, type $profile. See Microsoft's documentation for more details.

Any PowerShell code in this file gets evaluated at the start of console. This way you can have own aliases to be created at start.

How do I pipe non-ASCII content to ripgrep on Windows?

When piping input into native executables in PowerShell, the encoding of the input is controlled by the $OutputEncoding variable. By default, this is set to US-ASCII, and any characters in the pipeline that don't have encodings in US-ASCII are converted to ? (question mark) characters.

To change this setting, set $OutputEncoding to a different encoding, as represented by a .NET encoding object. Some common examples are below. The value of this variable is reset when PowerShell restarts, so to make this change take effect every time PowerShell is started add a line setting the variable into your PowerShell profile.

Example $OutputEncoding settings:

• UTF-8 without BOM: $OutputEncoding = [System.Text.UTF8Encoding]::new()
• The console's output encoding: $OutputEncoding = [System.Console]::OutputEncoding

If you continue to have encoding problems, you can also force the encoding that the console will use for printing to UTF-8 with [System.Console]::OutputEncoding = [System.Text.Encoding]::UTF8. This will also reset when PowerShell is restarted, so you can add that line to your profile as well if you want to make the setting permanent.

How is ripgrep licensed?

ripgrep is dual licensed under the Unlicense and MIT licenses. Specifically, you may use ripgrep under the terms of either license.

The reason why ripgrep is dual licensed this way is two-fold:

1. I, as ripgrep's author, would like to participate in a small bit of ideological activism by promoting the Unlicense's goal: to disclaim copyright monopoly interest.
2. I, as ripgrep's author, would like as many people to use rigprep as possible. Since the Unlicense is not a proven or well known license, ripgrep is also offered under the MIT license, which is ubiquitous and accepted by almost everyone.

More specifically, ripgrep and all its dependencies are compatible with this licensing choice. In particular, ripgrep's dependencies (direct and transitive) will always be limited to permissive licenses. That is, ripgrep will never depend on code that is not permissively licensed. This means rejecting any dependency that uses a copyleft license such as the GPL, LGPL, MPL or any of the Creative Commons ShareAlike licenses. Whether the license is "weak" copyleft or not does not matter; ripgrep will not depend on it.

Can ripgrep replace grep?

Yes and no.

If, upon hearing that "ripgrep can replace grep," you actually hear, "ripgrep can be used in every instance grep can be used, in exactly the same way, for the same use cases, with exactly the same bug-for-bug behavior," then no, ripgrep trivially cannot replace grep. Moreover, ripgrep will never replace grep.

If, upon hearing that "ripgrep can replace grep," you actually hear, "ripgrep can replace grep in some cases and not in other use cases," then yes, that is indeed true!

Let's go over some of those use cases in favor of ripgrep. Some of these may not apply to you. That's OK. There may be other use cases not listed here that do apply to you. That's OK too.

(For all claims related to performance in the following words, see my blog post introducing ripgrep.)

• Are you frequently searching a repository of code? If so, ripgrep might be a good choice since there's likely a good chunk of your repository that you don't want to search. grep, can, of course, be made to filter files using recursive search, and if you don't mind writing out the requisite --exclude rules or writing wrapper scripts, then grep might be sufficient. (I'm not kidding, I myself did this with grep for almost a decade before writing ripgrep.) But if you instead enjoy having a search tool respect your .gitignore, then ripgrep might be perfect for you!
• Are you frequently searching non-ASCII text that is UTF-8 encoded? One of ripgrep's key features is that it can handle Unicode features in your patterns in a way that tends to be faster than GNU grep. Unicode features in ripgrep are enabled by default; there is no need to configure your locale settings to use ripgrep properly because ripgrep doesn't respect your locale settings.
• Do you need to search UTF-16 files and you don't want to bother explicitly transcoding them? Great. ripgrep does this for you automatically. No need to enable it.
• Do you need to search a large directory of large files? ripgrep uses parallelism by default, which tends to make it faster than a standard grep -r search. However, if you're OK writing the occasional find ./ -print0 | xargs -P8 -0 grep command, then maybe grep is good enough.

Here are some cases where you might not want to use ripgrep. The same caveats for the previous section apply.

• Are you writing portable shell scripts intended to work in a variety of environments? Great, probably not a good idea to use ripgrep! ripgrep is has nowhere near the ubquity of grep, so if you do use ripgrep, you might need to futz with the installation process more than you would with grep.
• Do you care about POSIX compatibility? If so, then you can't use ripgrep because it never was, isn't and never will be POSIX compatible.
• Do you hate tools that try to do something smart? If so, ripgrep is all about being smart, so you might prefer to just stick with grep.
• Is there a particular feature of grep you rely on that ripgrep either doesn't have or never will have? If the former, file a bug report, maybe ripgrep can do it! If the latter, well, then, just use grep.

What does the "rip" in ripgrep mean?

When I first started writing ripgrep, I called it rep, intending it to be a shorter variant of grep. Soon after, I renamed it to xrep since rep wasn't obvious enough of a name for my taste. And also because adding x to anything always makes it better, right?

Before ripgrep's first public release, I decided that I didn't like xrep. I thought it was slightly awkward to type, and despite my previous praise of the letter x, I kind of thought it was pretty lame. Being someone who really likes Rust, I wanted to call it "rustgrep" or maybe "rgrep" for short. But I thought that was just as lame, and maybe a little too in-your-face. But I wanted to continue using r so I could at least pretend Rust had something to do with it.

I spent a couple of days trying to think of very short words that began with the letter r that were even somewhat related to the task of searching. I don't remember how it popped into my head, but "rip" came up as something that meant "fast," as in, "to rip through your text." The fact that RIP is also an initialism for "Rest in Peace" (as in, "ripgrep kills grep") never really dawned on me. Perhaps the coincidence is too striking to believe that, but I didn't realize it until someone explicitly pointed it out to me after the initial public release. I admit that I found it mildly amusing, but if I had realized it myself before the public release, I probably would have pressed on and chose a different name. Alas, renaming things after a release is hard, so I decided to mush on.

Given the fact that ripgrep never was, is or will be a 100% drop-in replacement for grep, ripgrep is neither actually a "grep killer" nor was it ever intended to be. It certainly does eat into some of its use cases, but that's nothing that other tools like ack or The Silver Searcher weren't already doing.