In BaSH pressing tab twice gives all possible commands for BaSH.

Try it , Learn and Enjoy

If you want to get all commands in any editor give the following script..

IFS=’:'; for i in `echo $PATH`; do echo $i|xargs ls; done >/tmp/commands.txt

it will save in the  /tmp directory.

Open it using your favourite editor…like  gedit /tmp/commands.txt