Many configuration parameters of Chimera and the
application specific meta data is accessed by reading, writing, or
creating files of the form
.(<command>)(<para>)
.
For example, the following prints the ChimeraID of the file
/data/some/dir/file.dat
:
[user] $
cat /data/any/sub/directory/'.(id)(file.dat)'
0004000000000000002320B8[user] $
From the point of view of the NFS
protocol, the file
.(id)(file.dat)
in the directory /data/some/dir/
is read. However,
Chimera interprets it as the command id
with
the parameter file.dat
executed in the
directory /data/some/dir/
. The quotes are
important, because the shell would otherwise try to interpret the
parentheses.
Some of these command files have a second parameter in a third
pair of parentheses. Note, that files of the form
.(<command>)(<para>)
are not really files. They are not shown when listing directories
with ls. However, the command files are listed
when they appear in the argument list of ls as
in
[user] $
ls -l '
-rw-r--r-- 11 root root 7 Aug 6 2010 .(tag)(sGroup).(tag)(sGroup)
'
Only a subset of file operations are allowed on these special command files. Any other operation will result in an appropriate error. Beware, that files with names of this form might accidentally be created by typos. They will then be shown when listing the directory.