1.\" Copyright (c) 1991, 1993 2.\" The Regents of the University of California. All rights reserved. 3.\" 4.\" Redistribution and use in source and binary forms, with or without 5.\" modification, are permitted provided that the following conditions 6.\" are met: 7.\" 1. Redistributions of source code must retain the above copyright 8.\" notice, this list of conditions and the following disclaimer. 9.\" 2. Redistributions in binary form must reproduce the above copyright 10.\" notice, this list of conditions and the following disclaimer in the 11.\" documentation and/or other materials provided with the distribution. 12.\" 3. All advertising materials mentioning features or use of this software 13.\" must display the following acknowledgement: 14.\" This product includes software developed by the University of 15.\" California, Berkeley and its contributors. 16.\" 4. Neither the name of the University nor the names of its contributors 17.\" may be used to endorse or promote products derived from this software 18.\" without specific prior written permission. 19.\" 20.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 21.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 24.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30.\" SUCH DAMAGE. 31.\" 32.\" @(#)getcwd.3 8.2 (Berkeley) 12/11/93 33.\" $FreeBSD: src/lib/libc/gen/getcwd.3,v 1.7.2.6 2001/12/14 18:33:51 ru Exp $ 34.\" $DragonFly: src/lib/libc/gen/getcwd.3,v 1.3 2006/05/26 19:39:36 swildner Exp $ 35.\" 36.Dd November 24, 1997 37.Dt GETCWD 3 38.Os 39.Sh NAME 40.Nm getcwd , 41.Nm getwd 42.Nd get working directory pathname 43.Sh LIBRARY 44.Lb libc 45.Sh SYNOPSIS 46.In unistd.h 47.Ft char * 48.Fn getcwd "char *buf" "size_t size" 49.Ft char * 50.Fn getwd "char *buf" 51.Sh DESCRIPTION 52The 53.Fn getcwd 54function copies the absolute pathname of the current working directory 55into the memory referenced by 56.Fa buf 57and returns a pointer to 58.Fa buf . 59The 60.Fa size 61argument is the size, in bytes, of the array referenced by 62.Fa buf . 63.Pp 64If 65.Fa buf 66is 67.Dv NULL , 68space is allocated as necessary to store the pathname. 69This space may later be 70.Xr free 3 Ns 'd . 71.Pp 72The function 73.Fn getwd 74is a compatibility routine which calls 75.Fn getcwd 76with its 77.Fa buf 78argument and a size of 79.Dv MAXPATHLEN 80(as defined in the include 81file 82.In sys/param.h ) . 83Obviously, 84.Fa buf 85should be at least 86.Dv MAXPATHLEN 87bytes in length. 88.Pp 89These routines have traditionally been used by programs to save the 90name of a working directory for the purpose of returning to it. 91A much faster and less error-prone method of accomplishing this is to 92open the current directory 93.Pq Ql .\& 94and use the 95.Xr fchdir 2 96function to return. 97.Sh RETURN VALUES 98Upon successful completion, a pointer to the pathname is returned. 99Otherwise a 100.Dv NULL 101pointer is returned and the global variable 102.Va errno 103is set to indicate the error. 104In addition, 105.Fn getwd 106copies the error message associated with 107.Va errno 108into the memory referenced by 109.Fa buf . 110.Sh ERRORS 111The 112.Fn getcwd 113function 114will fail if: 115.Bl -tag -width Er 116.It Bq Er EACCES 117Read or search permission was denied for a component of the pathname. 118.It Bq Er EINVAL 119The 120.Fa size 121argument is zero. 122.It Bq Er ENOENT 123A component of the pathname no longer exists. 124.It Bq Er ENOMEM 125Insufficient memory is available. 126.It Bq Er ERANGE 127The 128.Fa size 129argument is greater than zero but smaller than the length of the pathname 130plus 1. 131.El 132.Sh SEE ALSO 133.Xr chdir 2 , 134.Xr fchdir 2 , 135.Xr malloc 3 , 136.Xr strerror 3 137.Sh STANDARDS 138The 139.Fn getcwd 140function 141conforms to 142.St -p1003.1-90 . 143The ability to specify a 144.Dv NULL 145pointer and have 146.Fn getcwd 147allocate memory as necessary is an extension. 148.Sh HISTORY 149The 150.Fn getwd 151function appeared in 152.Bx 4.0 . 153.Sh BUGS 154The 155.Fn getwd 156function 157does not do sufficient error checking and is not able to return very 158long, but valid, paths. 159It is provided for compatibility. 160