using glob to substitute a variable-CodePudding

After reading some docs from globs in bash

https://mywiki.wooledge.org/glob#extglob

I´m struggling to replace a part of a variable:

Just an example that i am using to learn a bit more

myvar="value1=aaa value2=bbb value3=ccc value4=ddd"

value2="zzz"

myvar="${myvar//value2=*([a-z0-9-])/value2=${value2}}"

result:

echo $myvar
value1=aaa value2=zzz

expected result:

echo $myvar
value1=aaa value2=zzz value3=ccc value4=ddd

The result of the code above is not the expected one as it´s deleting everything behind value2=bbb in myvar.

If I use:

shopt -s extglob

it is working from a virtual machine with linux but from my current machine is not even if the begining of the script starts with #!/bin/bash. Most probably because i´m not using bash in my terminal.

Any other way to achieve this? (with sed for example without enabling extglob)

thx

CodePudding user response：

If you really can't use Bash, then you can maybe do what you want with lowest common denominator shell features like this:

pre=${myvar%%value2=*}
post=${myvar#"$pre"value2=}
v2=${post%%[!a-z0-9-]*}
post=${post#"$v2"}
myvar="${pre}value2=${value2}${post}"