How to check if currently running shell is BusyBox

Another way requiring Linux and readlink:

#!/bin/ash
exe=`exec 2>/dev/null; readlink "/proc/$$/exe"`
case "$exe" in
*/busybox)
    echo "It's a busybox shell."
    ;;
esac

Personally I favour:

if ps ax -o pid,comm | grep `echo $$` | grep busybox ; then
    echo "it is BusyBox"
fi

Which is a fair check to ensure you are running busybox shell.

This works by having ps generate a list of pids vs program names then finding our pid and checking if the program name contains busybox.

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