usr/src/lib/libc/gen/getcwd.3

.\" Copyright (c) 1991 The Regents of the University of California.
.\" All rights reserved.
.\"
.\" %sccs.include.redist.man%
.\"
.\"     @(#)getcwd.3    6.3 (Berkeley) %G%
.\"
.TH GETWD 3 ""
.UC 5
.SH NAME
getwd \- get working directory pathname
.SH SYNOPSIS
.nf
.ft B
char *getcwd(char *buf, size_t size);
char *getwd(char *buf);
.ft R
.fi
.SH DESCRIPTION
The
.I getcwd
function copies the absolute pathname of the current working directory
into the memory referenced by
.I buf
and returns a pointer to
.IR buf .
The
.I size
argument is the size, in bytes, of the array referenced by
.IR buf .
.PP
If
.I buf
is NULL, space is allocated as necessary to store the pathname.
This space may later be
.IR free 'd.
.PP
The function
.I getwd
is a compatibility routine which calls
.I getcwd
with its
.I buf
argument and a size of MAXPATHLEN (as defined in the include
file <sys/param.h>).
Obviously,
.I buf
should be at least MAXPATHLEN bytes in length.
.PP
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
.IR fchdir (2)
function to return.
.SH RETURN VALUES
Upon successful completion, a pointer to the pathname is returned.
Otherwise a NULL pointer is returned and
.I errno
is set to indicate the error.
In addition,
.I getwd
copies the error message associated with
.I errno
into the memory referenced by
.IR buf .
.SH ERRORS
.I Getcwd
will fail if:
.TP 15
[EACCESS]
Read or search permission was denied for a component of the pathname.
.TP 15
[EINVAL]
The
.I size
argument is zero.
.TP 15
[ENOENT]
A component of the pathname no longer exists.
.TP 15
[ENOMEM]
Insufficient memory is available.
.TP 15
[ERANGE]
The
.I size
argument is greater than zero but smaller than the length of the pathname
plus 1.
.SH BUGS
.I Getwd
does not do sufficient error checking and is not able to return very
long, but valid, paths.
It is provided for compatibility.
.SH SEE ALSO
chdir(2), fchdir(2), malloc(3), strerror(3)
.SH STANDARDS
.I Getcwd
conforms to IEEE Std 1003.1-1988 (``POSIX'').
The ability to specify a NULL pointer and have
.I getcwd
allocate memory as necessary is an extension.