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Last active December 27, 2022 15:52
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POSIX portable bash script
Raw
foo
if [ -z "${BASH_VERSION}" ]; then
exec bash "$@"
fi
# Bash script here
echo "${BASH_VERSION}"
@mentalisttraceur
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Pretty good, so long as no code exports BASH_VERSION into environment variables (which is a bad idea in most cases, but nearly inevitable given enough users, uses, and use-cases).

Could protect against that case by adding another if like this:

if test -n "`printenv BASH_VERSION`"
then
    unset BASH_VERSION
    exec bash "$@"
fi

(To support ancient shells it would be best to replace unset BASH_VERSION with

BASH_VERSION=
export BASH_VERSION

but for anything from the last decade or two it's probably overkill.)

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