File system 1

ODS-2:

Traditional file system on VMS.

Directory and file name syntax:

Case insensitive. Always shown in uppercase.

Full syntax: 

disk:[dir.subdir]name.type;version

Example: 

DKA0:[ARNE.CODE]FOOBAR.C;1

Normal syntax: 

name.type

Example: 

FOOBAR.C

The maximum length of name.type is 39+39. The maximum levels of directories are 8. Maximum total length is 255.

Version numbers:

Example:

  1. You edit a new file and save it as FOOBAR.C and it becomes FOOBAR.C;1
  2. You compile it, you get a syntax error, you edit FOOBAR.C and save and it becomes FOOBAR.C;2
  3. You compile it and the compiler generates FOOBAR.OBJ;1
  4. You edit FOOBAR.C and save and it becomes FOOBAR.C;3
  5. You compile it and the compiler generates FOOBAR.OBJ;2
  6. You link it and the linker create FOOBAR.EXE;1

(see compiler and linker commands here)

Normally you never explicit specify a version number. You only do that when you need a backup copy.

To cleanup all the version use the PURGE command. It deletes all versions except the highest version.

Version number syntax are:

n
version number n
0 (or omitted)
highest version number
-n
version number from the top (-1 is the second highest version number)
-0
lowest version number/dd>
*
all versions

Highest version number is 32767.

The DELETE command always want a version number to be sure you really want to delete the file (it is valid to specify * as version number).

Directory names:

Absolute directory names are [dir.subdir].

Relative directory names are [.subdir].

One level up is [-].

Current directory is [].

The top level directory can be referenced as [000000].

Recursing under directory is [dir...].

ODS-5

New file system on VMS that supports mixed case (Windows style not Unix style), spaces and dots.

More:

Continue here.