mirror of
https://github.com/freebsd/freebsd-src
synced 2024-09-06 17:18:32 +00:00
- Bump document date for eaccess(2) addition.
- Mention ``eaccess'' in the NAME section. - Use intro(2) terminology. - Markup fixes. Reviewed by: rwatson
This commit is contained in:
parent
146db49f97
commit
506d9c18e9
Notes:
svn2git
2020-12-20 02:59:44 +00:00
svn path=/head/; revision=84805
|
@ -32,12 +32,12 @@
|
|||
.\" @(#)access.2 8.2 (Berkeley) 4/1/94
|
||||
.\" $FreeBSD$
|
||||
.\"
|
||||
.Dd April 1, 1994
|
||||
.Dd September 21, 2001
|
||||
.Dt ACCESS 2
|
||||
.Os
|
||||
.Sh NAME
|
||||
.Nm access
|
||||
.Nd check access permissions of a file or pathname
|
||||
.Nm access , eaccess
|
||||
.Nd check accessibility of a file
|
||||
.Sh LIBRARY
|
||||
.Lb libc
|
||||
.Sh SYNOPSIS
|
||||
|
@ -53,35 +53,42 @@ and
|
|||
.Fn eaccess
|
||||
functions check the accessibility of the
|
||||
file named by
|
||||
the
|
||||
.Fa path
|
||||
argument
|
||||
for the access permissions indicated by
|
||||
.Fa mode .
|
||||
the
|
||||
.Fa mode
|
||||
argument.
|
||||
The value of
|
||||
.Fa mode
|
||||
is the bitwise inclusive OR of the access permissions to be
|
||||
is either the bitwise-inclusive OR of the access permissions to be
|
||||
checked
|
||||
.Pf ( Dv R_OK
|
||||
.Dv ( R_OK
|
||||
for read permission,
|
||||
.Dv W_OK
|
||||
for write permission and
|
||||
for write permission, and
|
||||
.Dv X_OK
|
||||
for execute/search permission) or the existence test,
|
||||
.Dv F_OK .
|
||||
for execute/search permission),
|
||||
or the existence test
|
||||
.Pq Dv F_OK .
|
||||
.Pp
|
||||
For additional information, see the
|
||||
.Dq File Access Permission
|
||||
.Sx "File Access Permission"
|
||||
section of
|
||||
.Xr intro 2 .
|
||||
.Pp
|
||||
The
|
||||
.Fn eaccess
|
||||
uses the effective user ID, group ID, and additional groups to authorize
|
||||
the request.
|
||||
call uses
|
||||
the effective user ID and the group access list
|
||||
to authorize the request;
|
||||
the
|
||||
.Fn access
|
||||
uses
|
||||
the real user ID in place of the effective user ID
|
||||
and the real group access list
|
||||
(including the real group ID) are
|
||||
used in place of the effective ID for verifying permission.
|
||||
call uses
|
||||
the real user ID in place of the effective user ID,
|
||||
the real group ID in place of the effective group ID,
|
||||
and the rest of the group access list.
|
||||
.Pp
|
||||
Even if a process's real or effective user has appropriate privileges
|
||||
and indicates success for
|
||||
|
@ -92,11 +99,7 @@ Likewise for
|
|||
and
|
||||
.Dv W_OK .
|
||||
.Sh RETURN VALUES
|
||||
If
|
||||
.Fa path
|
||||
cannot be found or if any of the desired access modes would
|
||||
not be granted, then a -1 value is returned; otherwise
|
||||
a 0 value is returned.
|
||||
.Rv -std
|
||||
.Sh ERRORS
|
||||
Access to the file is denied if:
|
||||
.Bl -tag -width Er
|
||||
|
@ -119,7 +122,7 @@ Permission bits of the file mode do not permit the requested
|
|||
access, or search permission is denied on a component of the
|
||||
path prefix.
|
||||
.It Bq Er EFAULT
|
||||
.Fa Path
|
||||
.Fa path
|
||||
points outside the process's allocated address space.
|
||||
.It Bq Er EIO
|
||||
An I/O error occurred while reading from or writing to the file system.
|
||||
|
@ -134,14 +137,19 @@ The
|
|||
function call is expected to conform to
|
||||
.St -p1003.1-90 .
|
||||
.Sh CAVEAT
|
||||
.Fn Access
|
||||
The
|
||||
.Fn access
|
||||
call
|
||||
is a potential security hole due to race conditions and
|
||||
should never be used.
|
||||
Setuid and setgid applications should restore the effective uid or gid
|
||||
Set-user-ID and set-group-ID applications should restore the
|
||||
effective user or group ID,
|
||||
and perform actions directly rather than use
|
||||
.Fn access
|
||||
to simulate access checks for the real user of group id.
|
||||
.Fn Eaccess
|
||||
to simulate access checks for the real user or group ID.
|
||||
The
|
||||
.Fn eaccess
|
||||
call
|
||||
likewise may be subject to races if used inappropriately.
|
||||
.Sh HISTORY
|
||||
An
|
||||
|
|
Loading…
Reference in a new issue