Hi All,

In linux, when you put an executable in the user's search path, and then when the user types the executable's name at the console, somehow the system finds out where the executable is located and executes it. My question is: is there anyway programmatically inside the executable file itself to know where it is located? To make it clear, say for example, you have an executable called "test", and you put this file in /usr/bin, then what I want is that during run time, test knows itself resides in /usr/bin.

The reason I ask this question is that I want to put some other accessory files for the executable together in the same directory, but the executable needs to know where itself is located. Somewhat irony! Is there any other way to deal with this issue?

Thanks a lot for your help.

Most programs know where they're installed because of configure, but that path has no meaning to the program in most situations under Linux. Data files and the like are installed to different directories. If you absolutely need that script to run in that directory, wrap it with a shell script.

One file I was thinking that needed to be put in the same directory as the executable is a logo file, basically a .xpm file. The executable has to know where the logo file is in order to load the logo automatically.

With configure, how do the programs know where they are installed since those information has to be stored in a file most likely, but the program needs to know where to locate that file? Sorry for my ignorance.

I guess one option I have is to ask the user to create an environment variable pointing to that directory.

Any other suggestions?

I don't think Zombie understood you completely...

"which <progname>"

Gives you where an application is if it's in PATH.

Thanks, Aeiri,

using your way would give the user the location of the executable, but I need to have the executable itself know programattically where it is located.

A program can do getpid() to get its own process ID, and if you wanted to, you could then have it use a call to the procfs to get its "exe" name (full pathname). Pick a process on your machine and do ls -l /proc/<pid>/exe to see what I mean.

Thanks, PaulFrields.

Your method worked great, by the way, how portable is this method among different linux and unix?

Not sure about other UNIX... I would suspect getpid() is fairly portable, since it conforms to POSIX, BSD 4.3, etc.... see man page for more info. Procfs is a Linux animal though. Seems to me you should be able to Google for more info.