Header Files

Header files access header information using normal D3 utilities.

Through the OSFI, it is possible to access information about an item such as update stamps, permissions, ownership, and driver-specific data. The header driver translates this information into a format that looks like a standard D3 item.

NOTE

Access to the header information via this driver is read-only. The only way to modify the header information is through the normal update routines. This is enabled via the Y correlative for D3 files. With the Y correlative, the user, PIB, and/or timedate can be stamped by appending a u, p, and/or t to the y character. No other information is currently available for normal items. Header information updates on non-D3 items depend on the behavior of the remote file system to which those items belong.

Any utility that physically moves the data (such as copy) changes the header information.

The save and restore utilities save and restore the header information as well.

Raw Attribute Definitions

When reading items via the header driver, the items are returned as a dynamic array with the following raw attribute definitions:

NOTE

Attributes 11-14 apply only for UNIX.

 

Attribute

Description

md Entry

1 User-ID

D3 user name or the UNIX user number in hexadecimal of the last user to update this item.

hdr.user

2 PIB

D3 PIB (in hexadecimal) of the last user to update this item. This field is undefined for non-D3 drivers.

hdr.pib

3 Time/date

Hexadecimal representation of the number of seconds elapsed since 12:00 AM December 31, 1967 and the time the item was last updated.

hdr.date and hdr.time

4 Permissions

Hexadecimal number representing the permissions on the item. This currently only applies to non-D3 items.

N/A

5 GroupID

Group ID (in hexadecimal). Currently used only by the UNIX driver, but may be used by other drivers in the future.

N/A

6 - 10

Reserved

N/A

11

File type:

  • d directory

  • b block special file

  • c character special file

  • m multiplexor file

  • l symbolic link

  • p fifo

  • - regular file

  • ? unknown file type

hdr:unix:type

12

Size in decimal.

hdr:unix:bytes

13

Mode in octal.

hdr:unix:omode

14

Mode in text format (-rwxrwxrwx).

hdr:unix:mode

15

User-ID in decimal.

hdr:unix:uid

16

User-ID name.

hdr:unix:user

17

Group ID in decimal.

hdr:unix:gid

18

Group ID name.

hdr:unix:group

19

Creation date in decimal.

hdr:unix:cdate

20

Creation time in decimal.

hdr:unix:ctime

21

Modification date in decimal.

hdr:unix:mdate

22

Modification time in decimal.

hdr:unix:mtime

23

Access date in decimal.

hdr:unix:adate

24

Access time in decimal.

hdr:unix:atime

Q-Pointer Format

The format of the header Q-pointer is:

file.name

 

001

Q

 

002

 

 

003

hdr:filename

where

hdr

Name of the hdr host in the dm,hosts, file.

filename

Name of the target file to examine. This can be a local D3 file (assuming the Y correlative has been added to the D-pointer), or a remote file (UNIX or MS-DOS).

The file can also be opened by pre-pending the file name with the string "hdr:".

WARNING

Because the hdr: driver is read-only, it does not make sense to create a QS-pointer to it (to attempt to save the header data). Any attempt to do this will have no effect upon a restore. Note that it is not necessary to save header information since it is implicitly saved and restored using the save and restore utilities.

Header information is not recorded on a t-dump since the succeeding t-load is considered to be a batch of new updates which change the header information in a driver-specific manner.

Note that updates performed to a file from a remote site will always show the updated user as dm.

See Also

copy Command

hosts File

Open Systems File Interface

QS-Pointer

save Command

Super Q-Pointer

Synonym-Defining Items