how to properly escape single quotes in regexp?

[JeffMelton]

There may be better ways to do this than regexp, but that's what I'm trying for now. I'm trying to pull the Ubuntu OS version from a string — this is a single value pulled from a VMware vSphere API endpoint. The only way so far I've managed to escape the single quotes is to use brace quotes:

$ out %(architecture='X86' bitness='64' distroName='Ubuntu 22.04.3 LTS' distroVersion='22.04' familyName='Linux' kernelVersion='5.15.0-94-generic' prettyName='Ubuntu 22.04.3 LTS') -> set string_value
$ out $string_value -> regexp %(s/.*prettyName='(.*)'.*$/$1/)
--quiet

As you can see, that returns a value that isn't in the string at all. I'm pretty sure that's from murex --quiet, which is how I launch the shell in my terminal emulator configs. I have validated the same behavior in both Kitty and WezTerm. I can skirt the issue by using a single-character . in lieu of the quotes:

$ out $string_value -> regexp 's/.*prettyName=.(.*)..*/$1/'
Ubuntu 22.04.3 LTS

But I'm really curious about a couple things:

1. How should I escape single quotes?
2. How in the world is Murex turning $1 in the first case into the argument passed to itself when its launched (if indeed that's what it is doing)?

[lmorg]

With the %() incantation, $1 is the reason you're seeing --quiet. If this is just a script then $1 would be the parameters passed to Murex. Which, in hindsight, isn't what you'd expect

In terms of the main ask, I think you'd be fine just with double quotes here, eg:

regexp "s/.*prettyName='(.*)'.*$/\$1/)"

Note here that I have escaped \$1

---

You can also use f/... to simplify the query:

regexp "f/prettyName='(.*)'"

https://murex.rocks/commands/regexp.html#find-elements

f/... might have some surprises if your string contains multiple instances of prettyName, but i don't think that's going to be a problem here.

[JeffMelton]

This is perfect, thank you. I hadn't thought about using f/... instead of s/..., but knowing I need to escape the $1 for substitution is also helpful.