Picking a Name for a New Command

When you write a new program or shell script, you'll probably want to be sure that its name doesn't conflict with any other commands on the system. For instance, you might wonder whether there's a command named tscan. You can check by typing one of the commands in the following example. If you get output (besides an error) from one of them, there's probably already a command with the same name. (The type command works on ksh, bash, and many Bourne shells; I've shown it with a dollar sign ($) prompt.)

which Section 2.6, whereis Section 2.3, alias Section 29.2

% man 1 tscan
No manual entry for tscan in section 1.
% which tscan
no tscan in . /xxx/ehuser/bin /usr/bin/X11 /usr/local/bin ...
% whereis tscan
tscan:
% alias tscan
%
% whatis tscan
tscan:
$ type tscan
tscan not found

— JP