Is there any way to make ripgrep return exit code 0 on no match?

[rew1nter]

Hi there.
I was executing ripgrep from code and found out this behavior. Is it possible to change the return code? if not what's the recommended solution?

[BurntSushi]

Short answer is that no, it isn't possible, and this is by design. In terms of what a recommend solution is, well, in order to say that, I need to know what the problem is. :-) Presuming you're writing a shell script, you might do rg foo || true. You might also use rg in an if statement. Honestly, there are a lot of different ways to approach it because it depends on what you're doing. And it's all pretty standard behavior because ripgrep behaves like grep here: exit with 0 when a match is found, 1 when no match is found and 2 when some other error occurs.

Probably this issue will give you the longer answer: #2500

[BurntSushi]

What is the expected result? Please try to simplify things here. Your regex pattern has escapes in places, and it's actually ambiguous to me what the intended result should be. Do you expect that ripgrep shouldn't match? And when you replace rg with grep, is the exit code the only difference?

[BurntSushi]

For example:

$ grep -v '(\[4[0-9]{2}\]|\[3[0-9]{2}\])' test
https://docs-dev.corp.google.com [302] [https://login.corp.google.com/request?s=docs-dev.corp.google.com:443/uberproxy/&d=https://docs-dev.corp.google.com/%3Fupxsrf%3DADM2IpRSKWoNJATW6bUrttPKMSp4lgLbGG_tf14D11XqYK1UrQ:1701788940589&maxAge=1200&authLevel=2000000&keyIds=M9V,bLf,DU5,2O9&c=1] [302 Moved] [HSTS]
https://frame.ds-next-external-devel.qa.adz.google.com [302] [https://login.corp.google.com/request?s=frame.ds-next-external-devel.qa.adz.google.com:443/uberproxy/&d=https://frame.ds-next-external-devel.qa.adz.google.com/%3Fupxsrf%3DADM2IpRa4bJ9bSKUSiIjKNnRS4muL9QmtAYJvXL_hd3daKZt-Q:1701788940992&maxAge=1200&authLevel=2000000&keyIds=M9V,bLf,DU5,2O9&c=1] [302 Moved] [HSTS]

$ grep -E -v '(\[4[0-9]{2}\]|\[3[0-9]{2}\])' test

$ echo $?
1

I'm starting to think that the exit code is red herring here, and what you're actually asking about is why ripgrep isn't matching while grep is. But I can't make heads or tails of what you're actually trying to do here.

[rew1nter]

modulo the fact that grep doesn't support \d

Okay I just realized that this causes grep to return a match and ripgrep doesn't return any match. So both ripgrep and grep is behaving the same except for the fact that grep doesn't recognize \d

What is the expected result?

I want ripgrep to silently pass with exit status 0 when no match is found.

[BurntSushi]

Maybe this is what you want?

$ grep -E -v '([4[0-9]{2}]\|[3[0-9]{2}])' test
https://docs-dev.corp.google.com [302] [https://login.corp.google.com/request?s=docs-dev.corp.google.com:443/uberproxy/&d=https://docs-dev.corp.google.com/%3Fupxsrf%3DADM2IpRSKWoNJATW6bUrttPKMSp4lgLbGG_tf14D11XqYK1UrQ:1701788940589&maxAge=1200&authLevel=2000000&keyIds=M9V,bLf,DU5,2O9&c=1] [302 Moved] [HSTS]
https://frame.ds-next-external-devel.qa.adz.google.com [302] [https://login.corp.google.com/request?s=frame.ds-next-external-devel.qa.adz.google.com:443/uberproxy/&d=https://frame.ds-next-external-devel.qa.adz.google.com/%3Fupxsrf%3DADM2IpRa4bJ9bSKUSiIjKNnRS4muL9QmtAYJvXL_hd3daKZt-Q:1701788940992&maxAge=1200&authLevel=2000000&keyIds=M9V,bLf,DU5,2O9&c=1] [302 Moved] [HSTS]

$ echo $?
0

$ rg -v '([4[0-9]{2}]\|[3[0-9]{2}])' test
1:https://docs-dev.corp.google.com [302] [https://login.corp.google.com/request?s=docs-dev.corp.google.com:443/uberproxy/&d=https://docs-dev.corp.google.com/%3Fupxsrf%3DADM2IpRSKWoNJATW6bUrttPKMSp4lgLbGG_tf14D11XqYK1UrQ:1701788940589&maxAge=1200&authLevel=2000000&keyIds=M9V,bLf,DU5,2O9&c=1] [302 Moved] [HSTS]
2:https://frame.ds-next-external-devel.qa.adz.google.com [302] [https://login.corp.google.com/request?s=frame.ds-next-external-devel.qa.adz.google.com:443/uberproxy/&d=https://frame.ds-next-external-devel.qa.adz.google.com/%3Fupxsrf%3DADM2IpRa4bJ9bSKUSiIjKNnRS4muL9QmtAYJvXL_hd3daKZt-Q:1701788940992&maxAge=1200&authLevel=2000000&keyIds=M9V,bLf,DU5,2O9&c=1] [302 Moved] [HSTS]

$ echo $?
0

You opened this question asking about exit status codes, and ripgrep and grep should behave the same on that respect. But that does not mean that every single possible pattern has the same semantics in both ripgrep and grep. For example, grep 'a|b' and grep -E 'a|b' are two entirely different patterns. In the former case, | is matched literally, but in the latter case, | means "or" so it matches "a" or "b".

ripgrep isn't a drop-in replacement for grep. Its exit status behavior should be the same, but the patterns each supports are not.

[BurntSushi]

I want ripgrep to silently pass with exit status 0 when no match is found.

grep doesn't do that either, as I demonstrated above. If you can provide a precise reproduction where this is not the case, I'd be happy to take a look. But I haven't seen one yet.

Otherwise, add || true to the end of your shell command, as I said initially:

package main

import (
	"log"
	"os"
	"os/exec"
)

func main() {
	cmd := exec.Command(
		"bash",
		"-c",
		`cat test | rg -v '(\[4[0-9]{2}\]|\[3[0-9]{2}\])' || true`,
	)
	cmd.Stderr = os.Stderr
	cmd.Stdout = os.Stdout
	if err := cmd.Run(); err != nil {
		log.Fatal(err)
	}
}

[rew1nter]

grep doesn't do that either, as I demonstrated above

Understood :)

Maybe this is what you want?

Yep. This regex seems to have solved the problem (\[4[0-9]{2}\]|\[3[0-9]{2}\]).

Otherwise, add || true to the end of your shell command,

I haven't understood the usage of this || true .
I also don't understand why [0-9] and \d causes different behaviour here

[rew1nter]

Btw thanks for helping me with this

[BurntSushi]

I also don't understand why [0-9] and \d causes different behaviour here

My opinionated answer is that POSIX is to blame. Tools like grep are supposed to conform to a standard called POSIX, and POSIX exists to provide "portability." But in actual fact, POSIX is somewhat barebones on its own. So tools like, for example, GNU grep are said to be "POSIX compatible," but they actually provide a lot more than what POSIX requires. Notice how the POSIX specification for grep is tiny.

The POSIX specification for regexes actually does not define \w, \s or \d at all. Yet, your copy of grep almost certainly provides \w and \s. Yet, it doesn't provide \d. I have no clue why. You can use grep -P and get \d. For GNU grep anyway.

Interestingly, my copy of BSD grep on my mac machine does let you match \d:

$ grep -V
grep (BSD grep, GNU compatible) 2.6.0-FreeBSD

$ echo 5 | grep '\d'
5

Who woulda thunk it. Lol. This is what "POSIX compatibility" means. As long as you're very familiar with the specification, you can use tools in a way that is POSIX compatible by artificially restricting yourself to what is specified. But as soon as you start doing stuff outside what is specified---and nobody will tell you when you do!---you enter into a land where portability is no longer guaranteed.

I haven't understood the usage of this || true .

It's part of your shell. It's a boolean expression. So if you do cmd1 || cmd2 || ... || cmdN, then cmd1 will run, and if it succeeds, things stop. Otherwise, if it fails, cmd2 is run. And so on. They are commonly found in if statements, but they can be used anywhere.