Thanks Joe, So with respect to point #5. My users on the PC shipping application would need a PC program to take their data and by being mapped to the IFS, it would transfer their data directly like that?
________________________________
From: Joe Pluta <joepluta@xxxxxxxxxxxxxxxxx>
To: Midrange Systems Technical Discussion <midrange-l@xxxxxxxxxxxx>
Sent: Thursday, January 1, 2009 12:09:57 PM
Subject: Re: Use of the IFS
Adam West wrote:
Yes I am not that familiar with stream files actually. How are they used?
Adam, just to give you an inkling of what the IFS is about:
1. The IFS is a hierarchical system of folders within folders, much as
you would see on a PC or on any Unix system (more like Unix, actually,
as there are no "drives" like there are on PCs).
2. All of the objects we green screen dinosaurs are familiar with
(libraries, files, members, programs, data areas, you name it) are
stored in a folder called QSYS.LIB.
3. Many of the IBM folders start with (go figure!) the letter Q - those
are typically folders that are very i specific.
4. Other standard folders have a distinctly Unix feel to them, with
names like /tmp and /home.
5. Users on other machines can "map" drives or folders to your IFS.
That is, you can create a folder on the IFS, and then other machines in
your network can link to that folder and then access files on the folder
as if that file were on their machine locally. No FTP required.
6. Similarly, a special folder name in the IFS, QNTC, allows you to
access network-shared folders on other machines from the i. That is,
the folder on some PC can be shared on the network and your i can read
and write directly to that folder.
7. Typically, the files in the non-QSYS folders are treated as "stream
files" which are "streams" of bytes - you usually don't deal with them
as having fixed-length records and fields. Although that can happen,
it's typically not done. Instead, you usually start reading the file at
the beginning and run through it to the end - hence the term "stream".
8. The types of information stored in stream files includes but is
certainly not limited to: simple text files, office documents of all
persuasions, PDF documents, pictures in various formats (JPEG, PNG,
etc.), and source and compiled objects for all manner of programming
languages, from Java to C to PHP, and source for interpreted languages
such as JavaScript and HTML.
The IFS allows Java programs and Unix programs running under PASE to
access data natively, since those environments deal almost exclusively
with stream files. Any structured data is accessed through a database
engine, which typically also stores its data in stream files. For
example, I've been writing some articles on using MySQL on the i, and
when you create a table in MySQL it stores the data in stream files in
the IFS, not in DB2 tables in the QSYS file system. APIs exist for us
RPG folks to access that data as well, either in binary or in text
format, and for the latter to convert between our beloved EBCDIC and the
formats used in the IFS world (predominantly ASCII and Unicode).
Hope this gives you a little intro. Happy New Year!
Joe
midrange.com
