pattern substitution (bash)

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@ahmubashshir's blog

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${<name>%<pattern>}
matches and replaces it from the right once

${<name>#<pattern>}
same, but from left

${<name>##<pattern>}
replace all, from left

${<name>%%<pattern>}
replace all from right

can contain alphanumeric characters and [posix character classes]* and normal shell globs (?/*)

• depends on implementation(eg. sh provided by dash doesn’t support them)

eg.

test=a.b.c.d/e.f/g-h/i.j.k echo ${test%. _} echo ${test%%._ } echo ${test# _.} echo ${test##_ .} echo ${test%e.f/ _} echo ${test#_ /e.f} echo ${test%i.j.?}

snap:

[Image: Untitled 10.png]