Bash

711 readers

1 users here now

Talk about the Bash Shell and Bash scripting

founded 4 years ago

MODERATORS

[email protected]

How does this code work? (sh.itjust.works)

submitted 1 week ago by [email protected] to c/[email protected]

2 comments fedilink hide all child comments

I'm studying bash, and I came across this Stackoverflow thread which contains this bit of code:

var="abcde"
echo ${var%d*}

The output is abc, but I can't figure out why. I understand that %d is used to indicate an integer number and * represents anything, but I can't figure out why those together would truncate var to only 3 characters.

you are viewing a single comment's thread
view the rest of the comments

[–] [email protected] 20 points 1 week ago (1 children)

That's manipulation of the string held in var. Dollar sign and curly braces wrap the variable, the single percent sign say remove the shortest matching substring from the end of the variable contents, and the 'd*' is the substring to match, a lowercase d followed by any characters in this instance. var will still hold the entire original string, only the echo output is modified here. You can find more documentation here, https://tldp.org/LDP/abs/html/string-manipulation.html.

[–] [email protected] 4 points 1 week ago

That's the exact Bible I would have linked to.