Arch Linux

For example, let's say we have an AIF configuration resulting in these variables:

ALL_PACKAGES="pkg pkg-xyz xyz-pkg pkgxyz xyzpkg"
TARGET_PACKAGES_EXCLUDE="pkg"

The substitution at line 29 of core/libs/lib-software.sh looks like this in the current git tree:

if [ -n "$var_TARGET_PACKAGES_EXCLUDE" ]
then
for excl in $var_TARGET_PACKAGES_EXCLUDE
do
ALL_PACKAGES=${ALL_PACKAGES//$excl/}
done
fi

This will incorrectly result in ALL_PACKAGES="-xyz xyz- xyz xyz". The problem is that it doesn't correctly find package name boundaries (which are effectively whitespace or newlines). This is pretty easily reproducible in a bash prompt:

$ ALL_PACKAGES="pkg pkg-xyz xyz-pkg pkgxyz xyzpkg"
$ echo $ALL_PACKAGES
pkg pkg-xyz xyz-pkg pkgxyz xyzpkg
$ ALL_PACKAGES=${ALL_PACKAGES//pkg/}
$ echo $ALL_PACKAGES
-xyz xyz- xyz xyz


I replaced the substitution with this, which worked correctly:

        if [ -n "$var_TARGET_PACKAGES_EXCLUDE" ]
        then
                for excl in $var_TARGET_PACKAGES_EXCLUDE
                do
                        ALL_PACKAGES=$(echo "$ALL_PACKAGES" | awk 'BEGIN { RS="[ \t\n]+" } !/^'"$excl"'$/ { print $1 }')
                done
        fi

Here's a test case demonstrating the difference:

$ ALL_PACKAGES="pkg pkg-xyz xyz-pkg pkgxyz xyzpkg"
$ echo $ALL_PACKAGES
pkg pkg-xyz xyz-pkg pkgxyz xyzpkg
$ excl=pkg; ALL_PACKAGES=$(echo "$ALL_PACKAGES" | awk 'BEGIN { RS="[ \t\n]+" } !/^'"$excl"'$/ { print $1 }')
$ echo $ALL_PACKAGES
pkg-xyz xyz-pkg pkgxyz xyzpkg
$

The disadvantage is that this feels a bit heavy-handed and complicated. I'm just not sure how to elegantly solve the issue using bash constructs.