Re: Regex and glob patterns in Parameter Expansion

[Bipul kumar]

I think the bash shell parameter expansion is for glob patterns only and
used for substitution.












*root@client:~#str="Hello World"root@client:~#new_str=${str##*
}root@client:~#echo $new_strWorldroot@client:~#str="Hello
World"root@client:~#new_str=${str%% *}root@client:~#echo
$new_strHelloroot@client:~#str="Hello
World"root@client:~#new_str=${str/World/}root@client:~#echo $new_strHello*

glob is basic pattern matching you will find inside the gnu pattern
matching.
And yes Glob patterns are simpler and more limited in scope than regular
expressions.

source:
https://www.gnu.org/software/bash/manual/html_node/Pattern-Matching.html

    Respectfully,
    Bipul
    PUBLIC KEY <http://ix.io/1nWf>
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                    ** Please excuse brevity and typos. **


On Sun, Mar 19, 2023 at 6:50 PM uzibalqa <uzibalqa@proton.me> wrote:

>
> Does Shell Parameter Expansion accept regex or glob patterns?
>
> ${str/$ptrn/}
>
> ${str##$ptrn}
>
> ${str%%$ptrn}/}
>
>