#include <unistd.h>char *getwd(char *path_name);
The getwd() function determines an absolute pathname of the current working directory of the calling process, and copies that pathname into the array pointed to by the path_name argument.
If the length of the pathname of the current working directory is greater than (PATH_MAX + 1) including the null byte, getwd() fails and returns a null pointer.
Upon successful completion, a pointer to the string containing the absolute pathname of the current working directory is returned. Otherwise, getwd() returns a null pointer and the contents of the array pointed to by path_name are undefined.
No errors are defined.
For portability to implementations conforming to versions of the X/Open Portability Guide prior to SUS, getcwd(3C) is preferred over this function.