Managing Systems and Workgroups: A Guide for HP-UX System Administrators

Configuring a System
Controlling Access to a System
Chapter 3 251
You can assign special privileges to a group of users using the
/usr/sbin/setprivgrp command. For information, refer to setprivgrp
(1M), setprivgrp (2), getprivgrp (2), rtprio (2), plock (2), shmctl (2), chown
(1), chown (2), getprivgrp (1), plock (2), shmctl (2),lockf (2), setuid (2),
setgid (2), and setgid (2).
Setting File Access Permissions
The /usr/bin/chmod command changes the type of access (read, write,
and execute privileges) for the file’s owner, group members, or all others.
Only the owner of a file (or the superuser) can change its read, write, and
execute privileges. For details, see chmod (1).
By default, new files have read/write permission for everyone
(-rw-rw-rw-) and new directories have read/write/execute permission
for everyone (drwxrwxrwx). Default file permissions can be changed
using the /usr/bin/umask command. For details, see umask (1). The
default for trusted systems is different; see “Setting Up Your Trusted
System” on page 790.
Setting Ownership for Files
The /usr/bin/chown command changes file ownership. To change the
owner, you must own the file or have superuser privileges.
The /usr/bin/chgrp command changes file group ownership. To change
the group, you must own the file or have superuser privileges.
For more information, refer to chown (1) and chgrp (1).
Setting Access Control Lists
Access control lists (ACLs) offer a finer degree of file protection than
traditional file access permissions. You can use ACLs to allow or restrict
file access to individual users unrelated to what group the users belong.
Only the owner of a file (or the superuser) can create ACLs.
ACLs are supported on both JFS and HFS file systems, but the
commands and some of the semantics differ. On a JFS file system, use
setacl(1) to set ACLs and use getacl(1) to view them. On an HFS file
system, use chacl(1) to set ACLs and use lsacl(1) to view them. For a
discussion of both JFS and HFS ACLs, see “Managing Access to Files
and Directories” on page 753. For additional JFS ACL information see
setacl (1), getacl (1), and aclv (5). For additional HFS ACL information,
see lsacl (1), chacl (1), and acl (5).