Loading variables in bash from another file - bash

Question

I build some ROMs and other software for various Android devices and to make it easier for me, I use bash based scripts.
Here's an example from my TWRP build script:
#!/usr/bin/env bash
# Variables
export TW_DEVICE_VERSION="0"
export BRANCH="android-5.1"
# Don't touch this
VERSION=$( grep "TW_MAIN_VERSION_STR" bootable/recovery/variables.h -m 1 | cut -d \" -f2 )-${TW_DEVICE_VERSION}
# Acer Liquid Z500 specific TWRP build configuration
export BRAND="acer"
export DEVICE="acer_Z500"
git clone https://github.com/liquidporting/android_device_${BRAND}_${DEVICE}.git -b ${BRANCH} device/${BRAND}/${DEVICE}
. build/envsetup.sh
lunch omni_${DEVICE}-eng
mka recoveryimage > twrp_${DEVICE}.log
cd out/target/product/${DEVICE}
if [ -f "recovery.img" ]
then
mv recovery.img twrp-${VERSION}-${DEVICE}.img
else
echo ""
echo "*******************************************************************************"
echo "Something went wrong during the build process, try checking your device tree."
echo "After that, run the script again and see if you messed up something new or not."
echo "*******************************************************************************"
echo ""
fi
if [ -f "twrp-${VERSION}-${DEVICE}.img" ]
then
megarm /Root/LPAD/TWRP/twrp-${VERSION}-${DEVICE}.img
megarm /Root/LPAD/TWRP/twrp_${DEVICE}.log
megaput --no-progress --path /Root/LPAD/TWRP twrp-${VERSION}-${DEVICE}.img
megaput --no-progress --path /Root/LPAD/TWRP ../../../../twrp_${DEVICE}.log
fi
if [ -f "twrp-${VERSION}-${DEVICE}.img" ]
then
cd ../../../..
rm twrp_${DEVICE}.log
make clean
cd device
rm -rf ${BRAND}
cd ..
else
rm twrp_${DEVICE}.log
make clean
cd device
rm -rf ${BRAND}
cd ..
echo ""
echo "**************************************************************"
echo "The build process of TWRP Recovery failed for device ${DEVICE}"
echo "**************************************************************"
echo ""
exit
fi
# Lenovo A328 specific TWRP build configuration
export BRAND="lenovo"
export DEVICE="A328"
git clone https://github.com/liquidporting/android_device_${BRAND}_${DEVICE}.git -b ${BRANCH} device/${BRAND}/${DEVICE}
. build/envsetup.sh
lunch omni_${DEVICE}-eng
mka recoveryimage > twrp_${DEVICE}.log
cd out/target/product/${DEVICE}
if [ -f "recovery.img" ]
then
mv recovery.img twrp-${VERSION}-${DEVICE}.img
else
echo ""
echo "*******************************************************************************"
echo "Something went wrong during the build process, try checking your device tree."
echo "After that, run the script again and see if you messed up something new or not."
echo "*******************************************************************************"
echo ""
fi
if [ -f "twrp-${VERSION}-${DEVICE}.img" ]
then
megarm /Root/LPAD/TWRP/twrp-${VERSION}-${DEVICE}.img
megarm /Root/LPAD/TWRP/twrp_${DEVICE}.log
megaput --no-progress --path /Root/LPAD/TWRP twrp-${VERSION}-${DEVICE}.img
megaput --no-progress --path /Root/LPAD/TWRP ../../../../twrp_${DEVICE}.log
fi
if [ -f "twrp-${VERSION}-${DEVICE}.img" ]
then
cd ../../../..
rm twrp_${DEVICE}.log
make clean
cd device
rm -rf ${BRAND}
cd ..
else
rm twrp_${DEVICE}.log
make clean
cd device
rm -rf ${BRAND}
cd ..
echo ""
echo "**************************************************************"
echo "The build process of TWRP Recovery failed for device ${DEVICE}"
echo "**************************************************************"
echo ""
exit
fi
Is possible to have a separated bash script containing build instructions and another one containing set of variables?
I Mean something like this:
#!/usr/bin/env bash
export TW_DEVICE_VERSION="0"
export BRANCH="android-5.1"
VERSION=$( grep "TW_MAIN_VERSION_STR" bootable/recovery/variables.h -m 1 | cut -d \" -f2 )-${TW_DEVICE_VERSION}
export BRAND="acer"
export DEVICE="acer_Z500"
export BRAND="lenovo"
export DEVICE="A328"
export BRAND="doogee"
export DEVICE="X5"
But after each device specific configuration I need it to launch the bash script containing the build instructions.

Answer 1

Yes, that is very much feasible and it is a good thing to do as well.
Put your configuration in a file, say, tw_config.sh. Then, invoke the configuration script this way:
source /path/to/tw_config.sh
if [ $? -ne 0 ]; then
# couldn't load config
# your logic here - makes sense to exit
fi
If tw_config.sh is in your PATH, you can simply say:
source tw_config.sh