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@(#)getcwd.3 8.2 (Berkeley) 12/11/93
$FreeBSD$
.Dd April 17, 2010 .Dt GETCWD 3 .Os .Sh NAME .Nm getcwd , .Nm getwd .Nd get working directory pathname .Sh LIBRARY .Lb libc .Sh SYNOPSIS n unistd.h .Ft char * .Fn getcwd "char *buf" "size_t size" .Ft char * .Fn getwd "char *buf" .Sh DESCRIPTION The .Fn getcwd function copies the absolute pathname of the current working directory into the memory referenced by .Fa buf and returns a pointer to .Fa buf . The .Fa size argument is the size, in bytes, of the array referenced by .Fa buf .
p If .Fa buf is .Dv NULL , space is allocated as necessary to store the pathname. This space may later be .Xr free 3 Ns 'd .
p The function .Fn getwd is a compatibility routine which calls .Fn getcwd with its .Fa buf argument and a size of .Dv MAXPATHLEN (as defined in the include file n sys/param.h ) . Obviously, .Fa buf should be at least .Dv MAXPATHLEN bytes in length.
p 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
q Ql .\& and use the .Xr fchdir 2 function to return. .Sh RETURN VALUES Upon successful completion, a pointer to the pathname is returned. Otherwise a .Dv NULL pointer is returned and the global variable .Va errno is set to indicate the error. In addition, .Fn getwd copies the error message associated with .Va errno into the memory referenced by .Fa buf . .Sh ERRORS The .Fn getcwd function will fail if: l -tag -width Er t Bq Er EINVAL The .Fa size argument is zero. t Bq Er ENOENT A component of the pathname no longer exists. t Bq Er ENOMEM Insufficient memory is available. t Bq Er ERANGE The .Fa size argument is greater than zero but smaller than the length of the pathname plus 1. .El
p The .Fn getcwd function may fail if: l -tag -width Er t Bq Er EACCES Read or search permission was denied for a component of the pathname. This is only checked in limited cases, depending on implementation details. .El .Sh SEE ALSO .Xr chdir 2 , .Xr fchdir 2 , .Xr malloc 3 , .Xr strerror 3 .Sh STANDARDS The .Fn getcwd function conforms to .St -p1003.1-90 . The ability to specify a .Dv NULL pointer and have .Fn getcwd allocate memory as necessary is an extension. .Sh HISTORY The .Fn getwd function appeared in x 4.0 . .Sh BUGS The .Fn getwd function does not do sufficient error checking and is not able to return very long, but valid, paths. It is provided for compatibility.