在Linux上获取程序的目录

Question

I'm wondering how I can get the directory of my program on Linux. For instance, if I have my program located under /home/myproject/ and I get the directory, it should be /home/myproject/ regardless of what directory I'm calling the program from. I need this functionality because I need to be able to access a configuration file located under the same folder as my program, regardless of where the program's folder is located.

I've tried using getcwd() , but here's what it does:

If I'm currently in the same folder as the program is, it will work. However, if I was in /root and tried executing the program which is located under /home/myproject , it would give me /root .

If I just do something like...

std::ifstream is("anotherfile");

It will work as long as I'm in the same directory, but it does the same as above when I'm not.

Answer 1

On Linux, you could use /proc/ . Read carefully proc(5) .

I'm suggesting reading the symlink in /proc/self/exe using readlink(2) . It gives your executable. You might use dirname(3) on it to get its directory. Be also aware of realpath(3) which might be useful (actually not, since, as commented by Daniel Schepler, /proc/self/exe is a canonical path....).

This is Linux specific, and won't work in rare pathological cases (your executable being removed or renamed during execution). See this .

Remember that Linux don't have folders (they are just a GUI artefact) but directories . See also opendir(3) , readdir(3) , closedir(3) , stat(2) , nftw(3) , etc....

At last, the Unix tradition is to keep user-specific configuration files under $HOME (often with hidden dotfile, eg $HOME/.inputrc ) and system-wide configuration files under /etc/ . You can get $HOME with getenv(3) as getenv("HOME") . See environ(7) . In pathological cases such a getenv could fail.

BTW, you could even adopt a convention of testing with getenv if some particular environment variable is set (eg MYPROGCONFIG ) and if it is set, use that as your configuration file. Don't forget to document such conventions.