NAME    [Toc]    [Back]

     getcwd, getwd - get working directory pathname

LIBRARY    [Toc]    [Back]

     Standard C Library (libc, -lc)

SYNOPSIS    [Toc]    [Back]

     #include <unistd.h>

     char *
     getcwd(char *buf, size_t size);

     char *
     getwd(char *buf);

DESCRIPTION    [Toc]    [Back]

     The getcwd() function copies the absolute pathname of the current working
     directory into the memory referenced by buf and returns a pointer to buf.
     The size argument is the size, in bytes, of the array referenced by buf.

     If buf is NULL, space is allocated as necessary to store the pathname.
     This space may later be free(3)'d.

     The function getwd() is a compatibility routine which calls getcwd() with
     its buf argument and a size of MAXPATHLEN (as defined in the include file
     <sys/param.h>).  Obviously, buf should be at least MAXPATHLEN bytes in
     length.

     These routines have traditionally been used by programs to save the name
     of a working directory for the purpose of returning to it.  A much faster
     and less error-prone method of accomplishing this is to open the current
     directory (`.') and use the fchdir(2) function to return.

RETURN VALUES    [Toc]    [Back]

     Upon successful completion, a pointer to the pathname is returned.  Otherwise
 a NULL pointer is returned and the global variable errno is set to
     indicate the error.  In addition, getwd() copies the error message associated
 with errno into the memory referenced by buf.

ERRORS    [Toc]    [Back]

     The getcwd() function will fail if:

     [EACCES]           Read or search permission was denied for a component
                        of the pathname.

     [EINVAL]           The size argument is zero.

     [ENOENT]           A component of the pathname no longer exists.

     [ENOMEM]           Insufficient memory is available.

     [ERANGE]           The size argument is greater than zero but smaller
                        than the length of the pathname plus 1.

SEE ALSO    [Toc]    [Back]

     chdir(2), fchdir(2), malloc(3), strerror(3)

STANDARDS    [Toc]    [Back]

     The getcwd() function conforms to ISO/IEC 9945-1:1990 (``POSIX.1'').  The
     ability to specify a NULL pointer and have getcwd() allocate memory as
     necessary is an extension.

HISTORY    [Toc]    [Back]

     The getwd() function appeared in 4.0BSD.

SECURITY CONSIDERATIONS    [Toc]    [Back]

     As getwd() does not know the length of the supplied buffer, it is possible
 for a long (but valid) path to overflow the buffer and provide a
     means for an attacker to exploit the caller.  getcwd() should be used in
     place of getwd() (the latter is only provided for compatibility purposes).


BSD                            December 11, 1993                           BSD