getcwd, getwd - get working directory pathname
#include <unistd.h>
char *
getcwd(char *buf, size_t size);
char *
getwd(char *buf);
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.
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.
The getwd() 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.
chdir(2), fchdir(2), malloc(3), strerror(3)
The getcwd() function conforms to ANSI X3.159-1989 (``ANSI
C''). The
ability to specify a null pointer and have getcwd() allocate
memory as
necessary is an extension.
The getwd() function appeared in 4.0BSD.
The getwd() function does not do sufficient error checking
and is not
able to return very long, but valid, paths. It is provided
for compatibility.
OpenBSD 3.6 December 11, 1993
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