Bash Declare Your Own Function in .Profile File

you may declare your own function in .profile or .bashrc file: example as below

function rmdu {
md5 * | sort -k 4 | uniq -f 3 -d | tr -d '()' | cut -d " " -f 2| xargs rm -v
}
export -f rmdu

Don’t forget to run “source ~/.profile” or “source ~/.bashrc”.