getcwd - get pathname of current working directory

Syntax	#include <unistd.h> char *getcwd(char *buf, int size);
Description	getcwd() returns a pointer to the current directory pathname. The value of size must be at least one greater than the length of the pathname to be returned. If buf is not null, the pathname will be stored in the space pointed to by buf. If buf is a null pointer, getcwd() will obtain size bytes of space by calling malloc(). In this case, the pointer returned by getcwd() may be used as the argument in a subsequent call to free(). The current directory will correspond to the home directory so long as no call to chdir() is made. The home directory can be checked with getpwuid() or getpwnam(). Both functions return a structure that includes a pointer to the original working directory. When a C program is started, the current directory is set to the home directory, as defined in the file SYSSRPM. If the environment variable HOME is defined for a C program, the home directory is set to that value. If the directory entered in the file SYSSRPM does not exist, a slash (/) is returned. BS2000 If an SDF-P variable SYSPOSIX.HOME exists, the HOME variable of the C programming environment is initialized with the value of the SYSPOSIX.HOME variable. (End) The current directory can be changed at any time by calling chdir(). The effect of a call to chdir() extends for the duration of the calling program. The home directory is not changed by the call.
Return val.	pointer to the current directory pathname
		if successful.
	0	if size is not large enough or an error occurs in a subordinate function. errno is set to indicate the error.
Errors	getcwd() will fail if:
	EACCES	The name of a parent directory could not be obtained because the directory could not be read.
	EINVAL	size is equal to 0.
	ENOMEM	Insufficient storage space is available.
	ERANGE	size is less than 0, or is greater than 0, but smaller than the length of the pathname + 1.
Notes	getcwd() is executed only for POSIX files
See also	malloc(), unistd.h.