HP 3000 Manuals HP 3000 Manuals
Summary of New Features
This section briefly introduces some of the new features of MPE/iX that
you will encounter in this tutorial:
* Hierarchical file system (HFS)
* HFS file names
* HFS syntax
* New and enhanced commands
Hierarchical file system (HFS)
As of Release 4.5 and 5.0, the MPE/iX file system is hierarchical (tree
structured) and can contain files at many different levels. This
organization provides a special kind of file called a directory. Instead
of holding data, directories contain lists of files and pointers to those
files. A directory can also contain other directories. This
organization is similar to the file systems on UNIX(R)or MS-DOS(R)
systems.
The new file organization still includes the familiar accounts, groups,
and users. The hierarchical file system (called HFS, for short) extends
the traditional MPE file system features so the operating system is more
flexible. You'll learn more about HFS as you work through the tutorial.
But keep in mind, unless you're going to use a new application that
requires the new items (such as directories), you can continue to use MPE
as you have in the past.
You're used to referring to files, groups, and accounts using the
traditional MPE syntax: FILE1.PUB.SYS. You can still use MPE syntax.
You can also make use of a new syntax called HFS syntax, which looks like
this: /SYS/PUB/FILE1.
The MPE/iX enhancements are compared to previous releases in Table 1-1
.
Table 1-1. Where Accounts, Groups, Directories, & Files Can Be Located
----------------------------------------------------------------------------------------------
| | | |
| Location | Before Release 4.5 | Release 4.5 and After |
| | | |
----------------------------------------------------------------------------------------------
| | | |
| Highest level | Accounts | Root |
| | | |
----------------------------------------------------------------------------------------------
| | | |
| Under root | Root not visible | Accounts, directories, or |
| | | files |
| | | |
----------------------------------------------------------------------------------------------
| | | |
| Under accounts | Groups | Groups, directories, and |
| | | files |
| | | |
----------------------------------------------------------------------------------------------
| | | |
| Under groups | Files | Directories or files |
| | | |
----------------------------------------------------------------------------------------------
| | | |
| Under directories | Directories not available | Directories or files |
| | | |
----------------------------------------------------------------------------------------------
Figure 1-1 shows how you can organize files, accounts, groups, and
directories in the file system. Notice that accounts, directories,
groups, and files all connect back to one directory designated by a slash
(/). This is referred to as the root or the root directory.
![[]](../../pic3k/M013448/FFN73c50.gif)
Figure 1-1. MPE/iX File System Example
HFS file names
MPE/iX now allows you to assign longer file names than in previous
versions of MPE/iX. Table 1-2 summarizes name lengths for accounts,
groups, directories, and files previous to Release 4.5 or greater.
Table 1-2. Maximum Lengths of Account, Group, Directory, and File Names
-------------------------------------------------------------------------------------------------
| | | |
| Type | MPE Syntax | HFS Syntax |
| | | |
-------------------------------------------------------------------------------------------------
| | | |
| Account name | 8 uppercase characters | 8 uppercase characters |
| | | |
-------------------------------------------------------------------------------------------------
| | | |
| Group name | 8 uppercase characters | 8 uppercase characters |
| | | |
-------------------------------------------------------------------------------------------------
| | | |
| Directory name | Not available | 16 mixed case characters if directly |
| | | under root, account, or a group. Up |
| | | to 255 characters elsewhere. |
| | | |
-------------------------------------------------------------------------------------------------
| | | |
| File name | 8 uppercase characters | 16 mixed case characters if directly |
| | | under root, account, or a group. Up |
| | | to 255 characters elsewhere. |
| | | |
-------------------------------------------------------------------------------------------------
See "Summary of MPE/iX syntax features" in Chapter 2 for additional
information about name lengths.
HFS syntax
Table 1-3 summarizes some of the syntax enhancements introduced by
the MPE hierarchical file system. The syntax that you are used to still
works for files in groups and accounts. So to use HFS syntax, you must
precede file and directory names with ./ or /. Otherwise, MPE/iX treats
the names using traditional MPE syntax rules.
This manual refers to files that are named using HFS syntax as HFS files.
Table 1-3. Syntax Summary
-------------------------------------------------------------------------------------------------
| | | |
| Item | MPE Syntax | HFS Syntax |
| | | |
-------------------------------------------------------------------------------------------------
| | | |
| Specify file name | No special beginning | Name must be preceded by a ./ (dot |
| | character required: | slash) or / (slash): |
| | FILE.GRP.ACCT | /ACCT or ./dir1 |
| | | |
-------------------------------------------------------------------------------------------------
| | | |
| Name separators | . (period); / separates | / (slash) |
| | lockwords | |
| | | |
-------------------------------------------------------------------------------------------------
| | | |
| Way of specifying files | Bottom up: FILE.GRP.ACCT | Top down: |
| | | /ACCT/GRP/FILE |
| | | |
-------------------------------------------------------------------------------------------------
| | | |
| Case sensitivity | Not case sensitive; all | Case sensitive: /DIR/FILE1 and |
| | characters are shifted to | /DIR/file1 are two different files |
| | uppercase | |
| | | |
-------------------------------------------------------------------------------------------------
| | | |
| Special characters | Only alphanumeric | Alphanumeric, - (hyphen), . (dot), |
| | characters | and _ (underscore) are allowed |
| | | |
-------------------------------------------------------------------------------------------------
| | | |
| First character | Must be alphabetic | Can be alphanumeric, _ (underscore), |
| | | or . (dot) but not - (hyphen) |
| | | |
-------------------------------------------------------------------------------------------------
New commands
* ALTFILE alters a file's attributes such as UID and GID of a file,
directory, and MPE group or account (except that the GID may not
be altered for MPE groups or accounts).
* CHDIR lets you move your CWD (much like changing groups).
* DISKUSE displays disk space used by accounts, groups, and
directories, that is, all items in the hierarchical file system.
(The REPORT command still provides disk space accounting for
accounts and groups. It just won't include detailed information
about directories below accounts, and it does not report on
directory structures directly below the root.)
* NEWDIR lets you create directories. After creating directories,
you can use the ALTSEC command if you want to grant access to
other users.
* NEWLINK creates a symbolic link to a file, group, account, or
directory.
* PURGEDIR is for deleting directories.
* PURGELINK is for removing a link.
* SETCLOCK alters the system time or system time zone.
* SHOWCLOCK displays information about the system date and time.
Enhanced commands
* FILE declares the file attributes to be used when a file is
opened. This declaration, informally known as a file equation,
may be used to override programmatic or system default file
specifications. With the addition of shared parameters from the
NS3000/XL AdvanceNet subsystem, the declaration may specify a
formal file designator that may be used to access a remote file or
device in a subsequent command or intrinsic.
* LISTF (UDC) executes the LISTFILE command to list descriptions of
one or more disk files.
* LISTFILE allows you to display directories and all HFS file names.
* PURGE deletes a file from the system.
* RESTORE returns files that have been stored on magnetic tape to
the system.
* RUN executes a prepared or linked program. The only required
parameter is progfile. If you specify any other parameters, they
will override the default parameters that the creator of the
program established, but only for that particular execution of the
program.
* SAVE command saves a file from the temporary domain to the
permanent domain.
* SHOWDEV reports the status of input/output devices.
* SHOWPROC displays information about one or more processes.
* STORE copies disk files onto a magnetic tape. Files copied to
tape with the STORE command can be recovered with the RESTORE
command.
* VSTORE verifies that the data on a backup media are valid and
reports errors incurred by STORE when writing the tape. VSTORE
only applies to NMSTORE tapes created in native mode. It does not
work on tapes created in compatibility mode.
Symbolic Links
Symbolic linking is the concept of indirectly referring (pointing) to
another file on the system. This concept is similar to MPE/iX file
equations. A symbolic link is a type of file that contains another path
name. It is a permanent file in the system directory. Symbolic links
can be created, removed, renamed, and archived.