I wanted to use 2.6.2 Parameter Expansion to remove leading characters from a string, but was surprised to find out that "Remove Largest Prefix Pattern" doesn't automatically repeat the pattern.

x=aaaaabc
printf %s\\n "${x##a}"

This only removes the first a. Now I'm struggling to figure out how I have to write the pattern if I want to remove as many a as possible from the beginning of $x. I had no luck searching either, because many answers use bash, but I'm looking for a POSIX shell solution. Am I overlooking something obvious? Should I open a question for this?

@rattlesnake ${x#${x%%[!a]*}}

Removes everything in $x from the first non-a character to the end, and then uses that result as the string to remove from the start of $x.

@Kusalananda Yes! :) I found that solution too

I'm terribly sorry, but I wasn't able to delete the chat messages above

@rattlesnake I don't think there's a need to delete it.

And I didn't want to link to the question because it's probably forbidden because it looks like I'm trying to draw more attention to it

(removed)

Still, thank you! :) I don't think it works with every pattern though

Right?

Hmm I wonder what happens if a starred message actually gets deleted

@jesse_b There you go.

If I want to remove ababab from the beginning I think there is no way to match the rest of the string

@jesse_b Huh? What does this mean? Were you able to remove your own message?

@rattlesnake Not with POSIX shell patterns, no.

@rattlesnake It just means he knows how to type "(remove)" in slanted font.

I wasn't able to edit the message either :(

Otherwise I would have done that

Edit to the code I posted earlier: ${x#"${x%%[!a]*}"}

You can delete them within a certain amount of time but in that case I just literally typed (removed)

The inner quotes make it possible to work with string containing shell patterns.

hell patterns sound metal

:-)

hell script programming is my forte

My work chat has a hellmo emoji and it's my favorite thing ever

@jesse_b Yeah okay, but I had only posted the question after 1 hour had passed after the chat message :) So I guess that "certain amount of time" was already over

@rattlesnake yeah I think it's like 5 minutes or something short