Using the dirname function, the following example reads a
      pathname, changes the current working directory to the parent
      directory, and opens a file.

            char path [MAXPATHLEN], *pathcopy;
            int fd;

            fgets(path, MAXPATHLEN, stdin);
            pathcopy = strdup(path);
            chdir(dirname(pathcopy));
            fd = open(basename(path), O_RDONLY);