diff options
author | ru <ru@FreeBSD.org> | 2001-10-11 15:27:53 +0000 |
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committer | ru <ru@FreeBSD.org> | 2001-10-11 15:27:53 +0000 |
commit | 39c4ae6616188368ff3a82d0693b645e7b6529a6 (patch) | |
tree | 8d84802d331b461c0fcbbbaf4313bd6e5eb477ed /lib/libc/sys/access.2 | |
parent | b0d7725e6d06b90f24cd57a55d75f334c3d5cce4 (diff) | |
download | FreeBSD-src-39c4ae6616188368ff3a82d0693b645e7b6529a6.zip FreeBSD-src-39c4ae6616188368ff3a82d0693b645e7b6529a6.tar.gz |
- Bump document date for eaccess(2) addition.
- Mention ``eaccess'' in the NAME section.
- Use intro(2) terminology.
- Markup fixes.
Reviewed by: rwatson
Diffstat (limited to 'lib/libc/sys/access.2')
-rw-r--r-- | lib/libc/sys/access.2 | 62 |
1 files changed, 35 insertions, 27 deletions
diff --git a/lib/libc/sys/access.2 b/lib/libc/sys/access.2 index 2460aec..1673cd4 100644 --- a/lib/libc/sys/access.2 +++ b/lib/libc/sys/access.2 @@ -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 |