Accessing the Fip Header - an overview

There are two main ways in which the data in the fip header is used:

1) A program acting on a file may be expecting certain header fields in

order to determine what to do with the file once it is received. Each program will deal with the file in a different way, and will interpret different parts of the file header so it is important to check the program documentation to see which fields are relevant (or necessary) to a particular program.
For instance ipwheel will look in the fip header and find the most recent instance of a DU field.

SN:file_Name
DU:ThePlaceToGo
~A file that we want to send on somewhere.  

ipwheel will look at the file header and see that the destination is "ThePlaceToGo", and will look up ThePlaceToGo in the tables/sys/USERS file, in order to determine what it should do with it.

In the users file ipwheel may find an entry like:

ThePlaceToGo   DP:localhost   DQ:the_destination_q   SC:yes   DC:no   QP:somthing_I_want_to_use_later

From this entry there are certain pieces of information that ipwheel needs: It adds every piece of information to the header, and if the fields are relevant to it, it acts accordingly. If they are not (like QP above - a user defined field for use later on in the files processing) it just adds the header field and ignores it.

So for instance, relevant fields here are:

• the DP: is the hostname (this machine or another) - if it is for another it sends it straight on to 2net for sending to that machine
• It reads the SC & DC and if they are different (as they are here) it adds the SC & DC header fields to the header and sends the file on to ipxchg to run an exchange called ~tables/xchg/YES2NO. ipxchg in turn sends the file on to the DQ: - "/fip/spool/the_destination_q".
• If the SC & the DC were the same, ipxchg would just send the file on to the destination directory.

2) A FIP parameter file which is in turn used by a program may call and

manipulate fip header fields*. This is called FipSeq

This is generally used by output formatting or transmission programs such as ipftp, ipedsys & ipbdcast. In these cases the parameter fies may do something like call the QP header field above and add it to the top of the file: for instance using [[Ipedsys][ipedsys], a program which is used for formatting output files and storing them

name:\SN.\QE
before:\QP\n\n
after:\n$D-$M-$E$Y --- end of this take ---\n

A file such as:

~ SN:filename_please QE:an_extension QP:some text to go at the top of the file` ~

Here is the body of my file as presented to ipedsys. Here is the body of my file as presented to ipedsys. Here is the body of my file as presented to ipedsys. Here is the body of my file as presented to ipedsys.

would output a file called filename_please.an_extension and would look like:

some text to go at the top of the file

Here is the body of my file as presented to ipedsys. Here is the body of my file as presented to ipedsys. Here is the body of my file as presented to ipedsys. Here is the body of my file as presented to ipedsys.

18-Mar-2001 --- end of this take ---

Links

See also FipHdr? , FipSeq