How do I change my pwd to the real path of a symlinked directory?

Question

Hi folks.

Here's a rather elementary *nix question:

Given the following symlink creation:

ln -s /usr/local/projects/myproject/ myproject

... from my home directory /home/jvf/, entering the myproject symlink gives me a pwd /home/jfv/myproject/. Now, I would like to enter the parent directory of the directory I've symlinked to, but the cd .. command will only bring me back to my home directory /home/jfv/. Is there anyway to escape the symlink trail that I've entered, and instead have a pwd equal to the actual path of the myproject directory. That is, changing my pwd from /home/jfv/myproject/ into /usr/local/projects/myproject/?

Thanks :)

Answer 1

Just use -P (physical) flag:

pwd -P

cd -P ..

Answer 2

Programmatically, you would do this with the getcwd library function:

#include <unistd.h>
#include <stdio.h>

int main(int argc, char **argv)
{
    char buf[1024*1024L];
    char *cwd;

    cwd = getcwd(buf, sizeof buf);
    if (cwd == NULL) {
        perror("getcwd");
        return 1;
    }
    printf("%s\n", cwd);
    return 0;
}

Answer 3

How can you force the -P option by default? I'm using zsh on Mac and I don't know how to change it.