From b8e6d50bbe9c2cfa9fd661e5090d2b1fa27c3429 Mon Sep 17 00:00:00 2001 From: Andrew Gallant Date: Mon, 12 Feb 2018 17:54:12 -0500 Subject: [PATCH] doc: add "grep replacement" question to FAQ I am tired of being throwing "but ripgrep is marketed as a grep replacement" in my face. Let's answer it once and for all. --- FAQ.md | 64 +++++++++++++++++++++++++++++++++++++++++++++++++++++++ README.md | 6 +++--- 2 files changed, 67 insertions(+), 3 deletions(-) diff --git a/FAQ.md b/FAQ.md index 184b401c..b7facfe3 100644 --- a/FAQ.md +++ b/FAQ.md @@ -20,6 +20,7 @@ * [How do I create an alias for ripgrep on Windows?](#rg-alias-windows) * [How do I create a PowerShell profile?](#powershell-profile) * [How do I pipe non-ASCII content to ripgrep on Windows?](#pipe-non-ascii-windows) +* [Can ripgrep replace grep?](#posix4ever)

@@ -466,3 +467,66 @@ 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. + + +

+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](https://blog.burntsushi.net/ripgrep/) +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. diff --git a/README.md b/README.md index ca1ed5ce..047ca06c 100644 --- a/README.md +++ b/README.md @@ -85,9 +85,9 @@ increases the times to `2.640s` for ripgrep and `10.277s` for GNU grep. ### Why should I use ripgrep? -* It can replace both The Silver Searcher and GNU grep because it is generally - faster than both. (N.B. It is not, strictly speaking, a "drop-in" replacement - for both, but the feature sets are far more similar than different.) +* It can replace many use cases served by both The Silver Searcher and GNU grep + because it is generally faster than both. (See [the FAQ](FAQ.md#posix4ever) + for more details on whether ripgrep can truly replace grep.) * Like The Silver Searcher, ripgrep defaults to recursive directory search and won't search files ignored by your `.gitignore` files. It also ignores hidden and binary files by default. ripgrep also implements full support