Re: [Gnumed-devel] Problems dumping database (Mac limitation on su -c)

[Jim Busser]

The failure of my backup script line

        chown ${BACKUP_OWNER} ${BACKUP_FILENAME}.tar

resulted (while regular user) on Mac OS in

        chown: djb.djb: Invalid argument 

and (while root) in

        chown: root.root: Invalid argument

seems a function of the script using the chown syntax "dot" delimiter

        owner[.group]

 whereas Mac requires the colon delimiter

        owner[:group]

See "COMPATIBILITY" comment below in my Mac OS output of man chown.

Can Debian / Linux / WIndows accept a script revision delimiting instead with 
colon ":"

??

*************************************************************************************

NAME
     chown -- change file owner and group

SYNOPSIS
     chown [-fhv] [-R [-H | -L | -P]] owner[:group] file ...
     chown [-fhv] [-R [-H | -L | -P]] :group file ...

DESCRIPTION
     The chown utility changes the user ID and/or the group ID of the specified 
files.  Symbolic links named by arguments are silently left
     unchanged unless -h is used.

     The options are as follows:

     -f      Don't report any failure to change file owner or group, nor modify 
the exit status to reflect such failures.

     -H      If the -R option is specified, symbolic links on the command line 
are followed.  (Symbolic links encountered in the tree traver-
             sal are not followed.)

     -h      If the file is a symbolic link, change the user ID and/or the 
group ID of the link itself.

     -L      If the -R option is specified, all symbolic links are followed.

     -P      If the -R option is specified, no symbolic links are followed.  
Instead, the user and/or group ID of the link itself are modi-
             fied.  This is the default. Use -h to change the user ID and/or 
the group of symbolic links.

     -R      Change the user ID and/or the group ID for the file hierarchies 
rooted in the files instead of just the files themselves.

     -v      Cause chown to be verbose, showing files as the owner is modified.

     The -H, -L and -P options are ignored unless the -R option is specified.  
In addition, these options override each other and the com-
     mand's actions are determined by the last one specified.

     The owner and group operands are both optional; however, at least one must 
be specified.  If the group operand is specified, it must be
     preceded by a colon (``:'') character.

     The owner may be either a numeric user ID or a user name.  If a user name 
is also a numeric user ID, the operand is used as a user name.
     The group may be either a numeric group ID or a group name.  If a group 
name is also a numeric group ID, the operand is used as a group
     name.

     For obvious security reasons, the ownership of a file may only be altered 
by a super-user.  Similarly, only a member of a group can
     change a file's group ID to that group.

DIAGNOSTICS
     The chown utility exits 0 on success, and >0 if an error occurs.

COMPATIBILITY
     Previous versions of the chown utility used the dot (``.'') character to 
distinguish the group name.  This has been changed to be a colon
     (``:'') character, so that user and group names may contain the dot 
character.

     On previous versions of this system, symbolic links did not have owners.

     The -v option is non-standard and its use in scripts is not recommended.

LEGACY DESCRIPTION
     In legacy mode, the -R and -RP options do not change the user ID or the 
group ID of symbolic links.

SEE ALSO
     chgrp(1), find(1), chown(2), fts(3), compat(5), symlink(7)

STANDARDS
     The chown utility is expected to be IEEE Std 1003.2 (``POSIX.2'') 
compliant.

HISTORY
     A chown utility appeared in Version 1 AT&T UNIX.

BSD                             March 31, 1994                             BSD
(END) 



-- Jim