It's possible to find the executable file's location by looking at "argv[0]" which is just the second item on the stack when the ELF exe starts up under Linux.

However, my experimentation indicates that the value given only contains the path to the file if it was explicitly given, but if the exe was found on $PATH somewhere, it will not be given.

So for example, if you have the exe 'myexe' then the 'argv[0]' will be:

if myexe is in the $PATH and you just type 'myexe', you will get 'myexe'
if you type the path to it, e.g. '/bin/myexe' you will get '/bin/myexe'.

Does anyone know how one can get the actual directory (fully qualified) where the exe being executed resides?

Hmm, I saw a post about this on a game developing oriented site a while ago (probably flipcode?), and it seemed that it was all but a trivial task. There was even a developer from loki soft (I think) who griped about it...

Yeah, I was thinking I could probably get it out of /proc ... I really don't want to do that if I don't have to.

In fact, /proc/<yourpid>/exe is a symlink to the executable. Now does anyone know just how to resolve a symlink to the file it points to? I know it's not hard, I just don't know how to do it

The 'net is great! "readlink" is the function.

First 'getpid' to get your process id, then readlink on '/proc/yourpid/exe' and you're done. 'readlink' returns the length of the string return, or -1 on failure.