man 3 getcwd 看看吧，也许有帮助！ 没玩过AIX！
Under Linux, the function getcwd() is a system call (since 2.1.92). On older systems it wouldquery /proc/self/cwd. If both system call and proc file system are missing, a generic imple-mentation is called. Only in that case can these calls fail under Linux with EACCES.