HPUX chownacl[3c]

 chownacl(3C)                                                   chownacl(3C)





 NAME
      chownacl() - change owner and/or group represented in a file's access
      control list (ACL)

 SYNOPSIS
      #include <acllib.h>

      void chownacl(
           int nentries,
           const struct acl_entry *acl,
           uid_t olduid,
           gid_t oldgid,
           uid_t newuid,
           gid_t newgid
      );

    Remarks:
      To ensure continued conformance with emerging industry standards,
      features described in this manual entry are likely to change in a
      future release.

 DESCRIPTION
      This routine alters an access control list (ACL) to reflect the change
      in a file's owner or group ID when an old file is copied to a new file
      and the ACL is also copied.  chownacl() transfers ownership (that is,
      it modifies base ACL entries) in a manner similar to chown() (see
      chown(2)).  The algorithm is described below and also in acl(5).

      The nentries parameter is the current number of ACL entries in the
      acl[] array (zero or more; a negative value is treated as zero).  The
      olduid and oldgid values are the user and group IDs of the original
      file's owner, typically the st_uid and st_gid values from stat() (see
      stat(2)).  The newuid and newgid values are the user and group IDs of
      the new file's owner, typically the return values from geteuid() and
      getegid() (see geteuid(2) and getegid(2)).

      If an ACL entry in acl[] has a uid of olduid and a gid of ACL_NSGROUP
      (that is, an owner base ACL entry), chownacl() changes uid to newuid
      (with exceptions - see below).  If an entry has a uid of ACL_NSUSER
      and a gid of oldgid (that is, a group base ACL entry), chownacl()
      changes gid to newgid.  In either case, only the last matching ACL
      entry is altered; a valid ACL can have only one of each type.

      As with chown(2), if the new user or group already has an ACL entry
      (that is, a uid of newuid and a gid of ACL_NSGROUP, or a uid of
      ACL_NSUSER and a gid of newgid), chownacl() does not change the old
      user or group base ACL entry; both the old and new ACL entries are
      preserved.

      As a special case, if olduid (oldgid) is equal to newuid (newgid),
      chownacl() does not search acl[] for an old user (group) base ACL



 Hewlett-Packard Company            - 1 -     HP-UX Release 9.0: August 1992






 chownacl(3C)                                                   chownacl(3C)





      entry to change.  Calling it with both olduid equal to newuid and
      oldgid equal to newgid causes chownacl() to do nothing.

    Suggested Use
      This routine is useful in a program that creates a new or replacement
      copy of a file whose original was (or possibly was) owned by a
      different user or group, and that copies the old file's ACL to the new
      file.  Copying another user's and/or group's file is equivalent to
      having the original file's owner and/or group copy and then transfer a
      file to a new owner and/or group using chown().  This routine is not
      needed for merely changing a file's ownership; chown() modifies the
      ACL appropriately in that case.

      If a program also copies file miscellaneous mode bits from an old file
      to a new one, it must use chmod() (see chmod(2)).  However, since
      chmod() deletes optional ACL entries, it must be called before
      setacl() (see setacl(2)).  Furthermore, to avoid leaving a new file
      temporarily unprotected, the chmod() call should set only the file
      miscellanous mode bits, with all access permission mode bits set to
      zero (that is, mask the mode with 07000).  The cpacl() library call
      encapsulates this operation, and handles remote files appropriately
      too.

 EXAMPLES
      The following code fragment gets stat() information and the ACL from
      oldfile, transfers ownership of newfile to the caller, and sets the
      revised ACL to newfile.

           #include <sys/types.h>
           #include <sys/stat.h>
           #include <sys/acl.h>

           int nentries;
           struct acl_entry acl [NACLENTRIES];
           struct stat statbuf;

           if (stat ("oldfile", & statbuf) < 0)
               error (...);

           if ((nentries = getacl ("oldfile", NACLENTRIES, acl)) < 0)
               error (...);

           chownacl (nentries, acl, statbuf.st_uid, statbuf.st_gid,
               geteuid(), getegid());

           if (setacl ("newfile", nentries, acl))
               error (...);

 AUTHOR
      chownacl() was developed by HP.




 Hewlett-Packard Company            - 2 -     HP-UX Release 9.0: August 1992






 chownacl(3C)                                                   chownacl(3C)





 SEE ALSO
      chown(2), getacl(2), getegid(2), geteuid(2), setacl(2), stat(2),
      acltostr(3C), cpacl(3C), setaclentry(3C), strtoacl(3C), acl(5).



















































 Hewlett-Packard Company            - 3 -     HP-UX Release 9.0: August 1992