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. Neither the name of the University nor the names of its contributors 13.\" may be used to endorse or promote products derived from this software 14.\" without specific prior written permission. 15.\" 16.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 17.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 18.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 19.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 20.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 21.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 22.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 23.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 24.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26.\" SUCH DAMAGE. 27.\" 28.Dd April 17, 2010 29.Dt GETCWD 3 30.Os 31.Sh NAME 32.Nm getcwd , 33.Nm getwd 34.Nd get working directory pathname 35.Sh LIBRARY 36.Lb libc 37.Sh SYNOPSIS 38.In unistd.h 39.Ft char * 40.Fn getcwd "char *buf" "size_t size" 41.Ft char * 42.Fn getwd "char *buf" 43.Sh DESCRIPTION 44The 45.Fn getcwd 46function copies the absolute pathname of the current working directory 47into the memory referenced by 48.Fa buf 49and returns a pointer to 50.Fa buf . 51The 52.Fa size 53argument is the size, in bytes, of the array referenced by 54.Fa buf . 55.Pp 56If 57.Fa buf 58is 59.Dv NULL , 60space is allocated as necessary to store the pathname. 61This space may later be 62.Xr free 3 Ns 'd . 63.Pp 64The function 65.Fn getwd 66is a compatibility routine which calls 67.Fn getcwd 68with its 69.Fa buf 70argument and a size of 71.Dv MAXPATHLEN 72(as defined in the include 73file 74.In sys/param.h ) . 75Obviously, 76.Fa buf 77should be at least 78.Dv MAXPATHLEN 79bytes in length. 80.Pp 81These routines have traditionally been used by programs to save the 82name of a working directory for the purpose of returning to it. 83A much faster and less error-prone method of accomplishing this is to 84open the current directory 85.Pq Ql .\& 86and use the 87.Xr fchdir 2 88function to return. 89.Sh RETURN VALUES 90Upon successful completion, a pointer to the pathname is returned. 91Otherwise a 92.Dv NULL 93pointer is returned and the global variable 94.Va errno 95is set to indicate the error. 96In addition, 97.Fn getwd 98copies the error message associated with 99.Va errno 100into the memory referenced by 101.Fa buf . 102.Sh ERRORS 103The 104.Fn getcwd 105function 106will fail if: 107.Bl -tag -width Er 108.It Bq Er EINVAL 109The 110.Fa size 111argument is zero. 112.It Bq Er ENOENT 113A component of the pathname no longer exists. 114.It Bq Er ENOMEM 115Insufficient memory is available. 116.It Bq Er ERANGE 117The 118.Fa size 119argument is greater than zero but smaller than the length of the pathname 120plus 1. 121.El 122.Pp 123The 124.Fn getcwd 125function 126may fail if: 127.Bl -tag -width Er 128.It Bq Er EACCES 129Read or search permission was denied for a component of the pathname. 130This is only checked in limited cases, depending on implementation details. 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