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Diffstat (limited to 'lib/libc/gen/getcwd.3')
-rw-r--r-- | lib/libc/gen/getcwd.3 | 162 |
1 files changed, 162 insertions, 0 deletions
diff --git a/lib/libc/gen/getcwd.3 b/lib/libc/gen/getcwd.3 new file mode 100644 index 0000000..88291c3 --- /dev/null +++ b/lib/libc/gen/getcwd.3 @@ -0,0 +1,162 @@ +.\" Copyright (c) 1991, 1993 +.\" The Regents of the University of California. All rights reserved. +.\" +.\" Redistribution and use in source and binary forms, with or without +.\" modification, are permitted provided that the following conditions +.\" are met: +.\" 1. Redistributions of source code must retain the above copyright +.\" notice, this list of conditions and the following disclaimer. +.\" 2. Redistributions in binary form must reproduce the above copyright +.\" notice, this list of conditions and the following disclaimer in the +.\" documentation and/or other materials provided with the distribution. +.\" 4. Neither the name of the University nor the names of its contributors +.\" may be used to endorse or promote products derived from this software +.\" without specific prior written permission. +.\" +.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND +.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE +.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE +.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE +.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL +.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS +.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) +.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT +.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY +.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF +.\" SUCH DAMAGE. +.\" +.\" @(#)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 +.In 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 . +.Pp +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 . +.Pp +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 +.In sys/param.h ) . +Obviously, +.Fa buf +should be at least +.Dv 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 +.Pq 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: +.Bl -tag -width Er +.It Bq Er EINVAL +The +.Fa size +argument is zero. +.It Bq Er ENOENT +A component of the pathname no longer exists. +.It Bq Er ENOMEM +Insufficient memory is available. +.It Bq Er ERANGE +The +.Fa size +argument is greater than zero but smaller than the length of the pathname +plus 1. +.El +.Pp +The +.Fn getcwd +function +may fail if: +.Bl -tag -width Er +.It 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 +.Bx 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. |