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'\"
'\" Copyright (c) 1998-1999 Scriptics Corporation
'\"
'\" See the file "license.terms" for information on usage and redistribution
'\" of this file, and for a DISCLAIMER OF ALL WARRANTIES.
'\"
'\" RCS: @(#) $Id: Access.3,v 1.10 2008/12/18 21:23:47 dkf Exp $
'\"
.so man.macros
.TH Tcl_Access 3 8.1 Tcl "Tcl Library Procedures"
.BS
.SH NAME
Tcl_Access, Tcl_Stat \- check file permissions and other attributes
.SH SYNOPSIS
.nf
\fB#include <tcl.h>\fR
.sp
int
\fBTcl_Access\fR(\fIpath\fR, \fImode\fR)
.sp
int
\fBTcl_Stat\fR(\fIpath\fR, \fIstatPtr\fR)
.SH ARGUMENTS
.AS "struct stat" *statPtr out
.AP char *path in
Native name of the file to check the attributes of.
.AP int mode in
Mask consisting of one or more of \fBR_OK\fR, \fBW_OK\fR, \fBX_OK\fR and
\fBF_OK\fR. \fBR_OK\fR, \fBW_OK\fR and \fBX_OK\fR request checking whether the
file exists and has read, write and execute permissions, respectively.
\fBF_OK\fR just requests a check for the existence of the file.
.AP "struct stat" *statPtr out
The structure that contains the result.
.BE
.SH DESCRIPTION
.PP
As of Tcl 8.4, the object-based APIs \fBTcl_FSAccess\fR and \fBTcl_FSStat\fR
should be used in preference to \fBTcl_Access\fR and \fBTcl_Stat\fR, wherever
possible. Those functions also support Tcl's virtual filesystem layer, which
these do not.
.SS "OBSOLETE FUNCTIONS"
.PP
There are two reasons for calling \fBTcl_Access\fR and \fBTcl_Stat\fR rather
than calling system level functions \fBaccess\fR and \fBstat\fR directly.
First, the Windows implementation of both functions fixes some bugs in the
system level calls. Second, both \fBTcl_Access\fR and \fBTcl_Stat\fR (as well
as \fBTcl_OpenFileChannelProc\fR) hook into a linked list of functions. This
allows the possibility to reroute file access to alternative media or access
methods.
.PP
\fBTcl_Access\fR checks whether the process would be allowed to read, write or
test for existence of the file (or other file system object) whose name is
\fIpath\fR. If \fIpath\fR is a symbolic link on Unix, then permissions of the
file referred by this symbolic link are tested.
.PP
On success (all requested permissions granted), zero is returned. On error (at
least one bit in mode asked for a permission that is denied, or some other
error occurred), -1 is returned.
.PP
\fBTcl_Stat\fR fills the stat structure \fIstatPtr\fR with information about
the specified file. You do not need any access rights to the file to get this
information but you need search rights to all directories named in the path
leading to the file. The stat structure includes info regarding device, inode
(always 0 on Windows), privilege mode, nlink (always 1 on Windows), user id
(always 0 on Windows), group id (always 0 on Windows), rdev (same as device on
Windows), size, last access time, last modification time, and creation time.
.PP
If \fIpath\fR exists, \fBTcl_Stat\fR returns 0 and the stat structure is
filled with data. Otherwise, -1 is returned, and no stat info is given.
.SH KEYWORDS
stat, access
.SH "SEE ALSO"
Tcl_FSAccess(3), Tcl_FSStat(3)
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