[unix-history] / 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.
Commit	Line	Data
e2462278 KB	1	.\" Copyright (c) 1991 The Regents of the University of California.
e2462278 KB	2	.\" All rights reserved.
861bcf00	3	.\"
e2462278 KB	4	.\" %sccs.include.redist.man%
	5	.\"
	6	.\" @(#)getcwd.3 6.3 (Berkeley) %G%
861bcf00	7	.\"
9594a5eb	8	.TH GETWD 3 ""
861bcf00 KM	9	.UC 5
861bcf00 KM	10	.SH NAME
e2462278	11	getwd \- get working directory pathname
861bcf00 KM	12	.SH SYNOPSIS
861bcf00 KM	13	.nf
e2462278 KB	14	.ft B
	15	char getcwd(char buf, size_t size);
	16	char getwd(char buf);
	17	.ft R
861bcf00 KM	18	.fi
861bcf00 KM	19	.SH DESCRIPTION
e2462278 KB	20	The
	21	.I getcwd
	22	function copies the absolute pathname of the current working directory
	23	into the memory referenced by
	24	.I buf
	25	and returns a pointer to
	26	.IR buf .
	27	The
	28	.I size
	29	argument is the size, in bytes, of the array referenced by
	30	.IR buf .
	31	.PP
	32	If
	33	.I buf
	34	is NULL, space is allocated as necessary to store the pathname.
	35	This space may later be
	36	.IR free 'd.
	37	.PP
	38	The function
	39	.I getwd
	40	is a compatibility routine which calls
	41	.I getcwd
	42	with its
	43	.I buf
	44	argument and a size of MAXPATHLEN (as defined in the include
	45	file <sys/param.h>).
	46	Obviously,
	47	.I buf
	48	should be at least MAXPATHLEN bytes in length.
	49	.PP
	50	These routines have traditionally been used by programs to save the
	51	name of a working directory for the purpose of returning to it.
	52	A much faster and less error-prone method of accomplishing this is to
	53	open the current directory (``.'') and use the
	54	.IR fchdir (2)
	55	function to return.
	56	.SH RETURN VALUES
	57	Upon successful completion, a pointer to the pathname is returned.
	58	Otherwise a NULL pointer is returned and
	59	.I errno
	60	is set to indicate the error.
	61	In addition,
	62	.I getwd
	63	copies the error message associated with
	64	.I errno
	65	into the memory referenced by
	66	.IR buf .
	67	.SH ERRORS
	68	.I Getcwd
	69	will fail if:
	70	.TP 15
	71	[EACCESS]
	72	Read or search permission was denied for a component of the pathname.
	73	.TP 15
	74	[EINVAL]
	75	The
	76	.I size
	77	argument is zero.
	78	.TP 15
	79	[ENOENT]
	80	A component of the pathname no longer exists.
	81	.TP 15
	82	[ENOMEM]
	83	Insufficient memory is available.
84	.TP 15
85	[ERANGE]
86	The
87	.I size
88	argument is greater than zero but smaller than the length of the pathname
89	plus 1.
90	.SH BUGS
861bcf00	91	.I Getwd
e2462278 KB	92	does not do sufficient error checking and is not able to return very
	93	long, but valid, paths.
	94	It is provided for compatibility.
	95	.SH SEE ALSO
	96	chdir(2), fchdir(2), malloc(3), strerror(3)
	97	.SH STANDARDS
	98	.I Getcwd
	99	conforms to IEEE Std 1003.1-1988 (``POSIX'').
	100	The ability to specify a NULL pointer and have
	101	.I getcwd
	102	allocate memory as necessary is an extension.