modify-debs

#!/bin/bash

#
# Based on https://unix.stackexchange.com/questions/138188/easily-unpack-deb-edit-postinst-and-repack-deb
#

modify_control() {
    #echo "modify_control $1"
    case "$1" in 
        Multi-Arch*)
            grep -q "^$1" control || sed -i "/^Architecture:/a $1" control
        ;;
    esac
}

repack_control() {
    cp ../$1 . && rm -rf tmp && mkdir -p tmp && cd tmp || return
    t=$(ar t ../$1 | grep control | sed "s/control.tar.//")
    d=$(ar t ../$1 | grep data)
    case "$t" in
        xz) 
            echo "Please note: changing control archive in package $1 from xz to gz"
            ar p ../$1 control.tar.xz | tar -xJ
            ar d ../$1 control.tar.xz
        ;;
        gz)
            ar p ../$1 control.tar.gz | tar -xz
        ;;
        *)
            return
        ;;
    esac
    modify_control "$2"
    tar czf control.tar.gz *[!z]
    ar -i $d -r ../$1 control.tar.gz
}

for deb in *.deb; do
    (
        mkdir -p repacked && cd repacked && rm -rf ./content && repack_control $deb "$1"
    )
done

if [ -d "$2" ]; then
    mv repacked/*.deb $2 && rm -rf repacked
    echo "Repacked packages has been put in folder $2"
else
    echo "Repacked packages are in repacked folder now"
fi