How to install busybox onto an Android emulator in order to access more linux commands

I have created the following script which can install busybox silently and headlessly via command line. It works on both 32-bit and 64-bit Android emulators.

Firstly, you should download busybox binary executable from https://busybox.net/downloads/binaries/ and copy it into your $HOME/bin folder.

Next, make a script called install-busybox.sh in $HOME/bin with the following content:

if [ $# == 0 ]; then
    devs="`adb devices | awk '{if(NF>0)print $0}' | sed -n '2,$p'`"
    N=`echo $devs | wc -l`
    if [ $N -gt 1 ]; then
        echo "Usage: $0 device-serial" >&2
        adb devices
        exit 1
    fi
    set -- `echo "$devs" | awk '{print $1}'`
fi

set -x

adb -s $1 root
adb -s $1 shell setenforce 0
adb -s $1 shell mount -o remount,rw /
adb -s $1 push $HOME/bin/busybox /sbin

# on 64-bit system, it fails
if [ $? != 0 ]; then
    adb -s $1 shell mount -o rw,exec,remount /mnt
    adb -s $1 shell cp -rfp '/sbin' /mnt/
    adb -s $1 shell mount /mnt/sbin /sbin
    adb -s $1 push $HOME/bin/busybox /sbin
fi

adb -s $1 shell /sbin/busybox --install -s /sbin
res=$?

set +x
if [ $res == 0 ]; then
    echo Successful
else
    echo Failed
fi

So far, I have tested it on API 26-28, but it might not work on all Android images.