Linux.com

It doesn't behave as you describe in bash. If I enter loc, for example, it doesn't complete the word, it merely lists the possible commands that could be completed starting with those 3 letters. If I enter lockf, so that only a single command is possible to complete, it does that and nothing else.

Joe Barr/K1GPL
Corporal-for-life
Linux Liberation Army

wit the exception that if there is locaa locab locac then lo<tab> will display 'loca' and an other (double) <tab> will display these three files.
also if it's the beginning of a line it wont complete anything that's not executable (and in the path or with the path explicitly given) so using the above example ls lo<tab> will expand to ls loca, but lo<tab> in itself will not do anything unless those three files are executable and in the path. ./lo<tab> will expand to ./loca if they're executable but not otherwise.