44.21 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 currency sign ($ ) prompt.)

which
 

whereis
 

alias
 

% 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


%

$ type tscan


tscan not found