HP 3000 Manuals HP 3000 Manuals
Using Symbolic Links
You have a lot of flexibility in naming directories and files by using
symbolic links. What if you want to move a set of files from one
location to another without affecting the normal processing of any
application that accesses those files. To do this, you can move the
actual files to the new location, and in the old location create symbolic
links with the same name specifying the CWD(s) of the new location of the
files.
To create symbolic links
A symbolic link is a type of file that contains another path name. It is
a permanent file in the system directory. This concept is similar to
MPE/iX file equations.
A symbolic link file may contain a relative or absolute path name. If a
symbolic link to a relative path name is encountered during path name
traversal, the contents of the symbolic link replace the symbolic link
component and is expanded into the path name being interpreted. If a
symbolic link to an absolute path name is encountered, the contents of
the symbolic link replaces all components up to and including the
symbolic link and is expanded into the remainder of the path name.
Creating symbolic links.
Suppose that files file1, file2, and file3 originally existed under the
group PXGROUP of account DEVELOP. You have decided to move the files to
the /users/denis/bin/FILES directory. To ensure that all of the
applications that access those files will still function properly, you
must create symbolic links to those files.
Use the NEWLINK command to create the symbolic links.
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| |
| |
| :chdir /DEVELOP/PXGROUP |
| :newlink ./file1, /users/denis/bin/FILES/file1 |
| :newlink ./file2, /users/denis/bin/FILES/file2 |
| :newlink ./file3, /users/denis/bin/FILES/file3 |
| |
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From this point on, anytime an application accesses these files, the
symbolic links will redirect the file system to the new location of the
files.
NOTE This only applies to commands that operate on the target of the
links and not the links themselves. For example, PURGELINK and
STORE operate on the link itself and not the target files.
You can use this method to install newer versions of these files in
another location without overlaying their current version, and changing
the symbolic links to point to the newer version. If at any time you
need to access the old version, you can point the symbolic links to that
version of the files.
Deleting symbolic links
Use the PURGELINK command to delete a symbolic link(s).
:newlink ./file1, /users/denis/bin/FILES/file1
Renaming symbolic links
Symbolic links can be renamed by calling the POSIX C-library function of
rename().
The MPE/iX command RENAME does not rename the symbolic link itself, it
renames the file pointed to by the symbolic link.
Archiving symbolic links
Symbolic links can be stored and restored to your MPE/iX system by using
the MPE/iX STORE and RESTORE commands like any other file on the system.