Finding out executable location from a c program

[Douglas Davidson]

On Nov 20, 2007, at 4:36 AM, Alastair Houghton wrote:

> It's perhaps worth saying though that using the path of your tool is  
> generally an evil thing to do.  It's normally best, for command line  
> tools, to hard-code paths to any resources they need in the normal  
> UNIX places, or to stick them inside an associated application and  
> use Launch Services to locate that (you probably want  
> LSFindApplicationForInfo()), then use CF or NSBundle to grab  
> references to the relevant files from there.

I might also mention that the path to the executable is not  
necessarily well-defined in general.  For example, by the time your  
executable is launched and running, the file system might have changed  
so that the file that was there no longer exists; something else  
entirely might be in its place.  There are a number of cases in which  
the executable content is actually defined by something other than the  
currently running Mach-o binary--for example, shell scripts, CFM  
executables, Java, and so forth.  If consistency with other behavior  
on the platform is an issue, I would recommend using CFBundle/NSBundle  
to obtain the executable path; it does its best to give a reasonable  
result, and it is the mechanism most generally used on the system.   
However, keep in mind that it may fail, and that no mechanism of this  
sort can succeed in all cases.  In particular, don't make security  
mechanisms dependent on being able to locate your executable.  If you  
need to examine the binary contents of your executable, you can look  
at the loaded version in your address space.

Douglas Davidson