Monster Media 1993 #2/Image.iso/os2/edmi3.zip/EDMI3.INF

OS/2 Help File | 1993-05-31 | 160KB | 2,416 lines

ΓòÉΓòÉΓòÉ 1. Title Page ΓòÉΓòÉΓòÉ

          Welcome to EDM/2 - The Electronic OS/2 Developers' Magazine!.

                  Portions Copyright (C)1993 by Steve Luzynski.

                            Issue #3 - May/June 1993.

                           (Press 'Forward' to page.)


ΓòÉΓòÉΓòÉ 2. Copyright Notice and other Legal Stuff ΓòÉΓòÉΓòÉ

EDM/2 Copyright (C)1993 by Steve Luzynski. This publication may be freely
distributed in electronic form provided that all parts are present in their
original unmodified form. A reasonable fee may be charged for the physical act
of distribution; no fee may be charged for the publication itself.

All articles are copyrighted by their authors. No part of any article may be
reproduced without permission from the original author.

Neither this publication nor Steve Luzynski is affiliated with International
Business Machines Corporation.

OS/2 is a registered trademark of International Business Machines Corporation.
Other trademarks are property of their respective owners. Any mention of a
product in this publication does not constitute an endorsement or affiliation
unless specifically stated in the text.


ΓòÉΓòÉΓòÉ 3. From the Editor ΓòÉΓòÉΓòÉ

 Well, EDM/2 has finally made it to its third issue! You've probably noticed
that this issue says 'May/June' on it - that's because I ran out of time to do
separate issues for each month. I'm back on schedule now, though.

This month, I happened upon an interesting little piece of software:

The Microsoft Upgrade Advisor

This is a free advertising tool MS has come up with to hype DOS 6.0 and
Windows. Oddly enough, you must have at least Windows 3.0 to run it.  No
problem - A double-click from the OS/2 drives object, and it started up.

After a few screens worth of stuff, it noted that I have OS/2 2.0 on my system.
It recommended that I 'upgrade' my 32 bit multitasking OS with DOS 6 + Windows
3.1. Obviously I'd want to drop back down to an 8 bit OS with a cute graphical
shell.

My point in bringing this up was not to trash MS in any way (although that's
sometimes fun too). Instead, it got me thinking about what they're doing. While
IBM does have an OS/2 demo disk out, I would never have seen it had I not been
poking around on Internet. On the other hand, I have 3 MS Upgrade Advisors.

Getting three free high-density disks wasn't bad, of course, but I am a bit
distressed to find that IBM isn't throwing their disk out in the quantities MS
is. Perhaps if IBM started pushing OS/2 as hard as MS pushes Windows, I might
be able to walk into a Babbage's or an Egghead and be able to pick DeScribe up
off of the shelf.

In other news...

Starting with the next issue, I hope to have a new column. The idea is this:
Each month, you, the readers, write up reivews of your favorite pieces of OS/2
development software. This can be any native OS/2 program, be it PM or text
mode. Originally, I was going to limit it to public domain tools, but I see no
reason to exclude commercial tools. After all, for upwards of 400 dollars in
most cases, I'd like to hear from someone else who has used a particular
program before I buy it.

At any rate, Larry Salomon and I will go through your articles and select which
ones get in to EDM/2. (Chances are that almost all of them will.) Here's yet
another chance to get your name up in lights!

Submissions can be in either .IPF format or plain ascii, and can be sent to
either [e-mail] (Larry) or [e-mail] (myself). I will be getting
back on schedule after this month, so for the July issue I'd like your
submissions no later than June 25th.

Submissions

Once again, I'd like to remind you all that I'm always in the market for
articles for EDM/2. No topic is too broad or too focused to not be of interest
to someone out there.

I prefer submissions in .IPF format, but if you don't know how to create an
.IPF file, plain ASCII is fine as well. The rules go like this:

For .IPF format submissions, your article should start at a heading level of
three. This is because the table of contents is at level one and the cover
panel (with the EDM/2 logo, article title, and author's name) is at level two.
This means that when you are writing your article, you'll need to include dummy
:h1 and :h2 panels.

Beyond that, do what you want. You can either write an elaborate article with
hotlinks to glossary items and animated example windows, or just stick with a
straightforward series of panels.

For ASCII format submissions, there are a few things that make my life a lot
simpler. First, since the .IPF tagging language uses colons to tell the
compiler that something is a command, colons should be represented as '&colon.'
rather than ':'. For the same reason, ampersands should be '&.' rather than
'&'.

Next, each new paragraph should start with ':p.'. This indicates to the IPF
compiler that it should start a new line. Any place you would like to put
special emphasis on a word or phrase, place asterisks (*) around the text. You
should also indicate what kind of emphasis you want: bold, italics,
underlining, or a combination of the three.

All submissions should come with a brief blurb describing the author. See the
'Contributors' section for several examples of what it should look like.

If you already have a piece you'd be willing to contribute, but don't want to
rework, contact me anyway and I'll arrange to convert your article for you.
Please note that: 1) I really hate doing it; and 2) I'll have to have your
article early so I have time to do the conversion. For example, converting
Andre's article on Installable File Systems in this issue from Word for Windows
format into what you see took me almost 3 hours!

Anyway...

In the future, I hope to include some how-to columns on using the help compiler
(.IPF files can compile to either .INF or .HLP files). For now, I'm including
in this issue's sample code both my editorial and the 'base' file for this
issue. While you won't be able to compile them directly without some reworking,
it should give you an idea of how to proceed.

Steve Luzynski, Editor.


ΓòÉΓòÉΓòÉ 4. This Month's Features ΓòÉΓòÉΓòÉ

o Dos Development Tools Under OS/2

o OS/2 Installable File Systems - Part 1

o Programming the Container Control - Part 1


ΓòÉΓòÉΓòÉ 4.1. Dos Development Tools Under OS/2 ΓòÉΓòÉΓòÉ

                              DOS Development Tools
                                      Under
                                      OS/2

                                Charles R. Oldham
                            ([e-mail])


ΓòÉΓòÉΓòÉ 4.1.1. Introduction ΓòÉΓòÉΓòÉ

In this new age of interoperability, OS/2 has been billed by the marketing
types as the Integrating Platform.  "Run your Windows, Dos, and OS/2
applications on one machine!  Preserve your existing investment in Dos and
Windows software--upgrade only when you are ready!" they cry.  Well, for a
change, the marketing people are on the right track.  OS/2 is indeed the
Integrating Platform, but there are far more advantages for the developer than
there are for the user.

For the first time developers have the ability to write software for two
different operating systems and three different operating environments: Dos,
Windows, and OS/2 PM (four if you count OS/2 text mode programs).  And we can
do it all from one machine that hosts a multitasking, multithreaded,
protected-mode operating system.  Unlike systems that support cross-compilers,
we are also able to test these applications to a great extent, using the Dos
and WinOS /2 subsystems of OS/2 2.x.

Developers are faced with a difficult question when a transition to a new
operating system is possible:

o How can I get the work done that I did before, but still utilize the full
  potential of the Operating System?

Frustration is a real possibility in a situation like this.  The developer may
discover after a few hours or days of programming that running a Borland IDE in
a Dos fullscreen session is still a lot like running Dos!

Though we seem to have all of OS/2's power at our fingertips, having to use Dos
tools to develop Dos programs limits us somewhat.  Dos tools are not
multitasking or multithreaded; they do not understand filenames that are not in
the 8.3 format; interprocess communication is almost nonexistent, or at best
limited due to the fact that Dos understands only the single process.

It is reasonable to conclude, therefore, that we would like to minimize our
contact with Dos tools, and maximize the number of OS/2 based tools that we
would use to get our work done.  Unfortunately, some tools, like compilers, in
tegrated development environments, and especially debuggers, are irreplaceable.

The question then becomes

o How can I minimize my contact with Dos while still utilizing my irreplaceable
  tools?


ΓòÉΓòÉΓòÉ 4.1.2. DPipeLn ΓòÉΓòÉΓòÉ

Origins, Usage, and Internal Structure


ΓòÉΓòÉΓòÉ 4.1.2.1. Origin ΓòÉΓòÉΓòÉ

The Origin of DPipeLn

The utility called DPipeLn was created because when developing for Dos, I
tended to find myself using a Dos box all day.  This frustrated me because I
felt like I wasn't using the abilities of OS/2.  Also, though I like Borland's
Integrated Development Environments, I find them somewhat cumbersome for large
projects, and I wanted to be able to use the more advanced utilities like
NMake, Gnu Make, and the other Gnu programming utilities that are rapidly being
ported to OS/2.  I thought about my requirements and realized that it was
probably possible to write an OS/2 utility that would start a Dos session
transparently, run the appropriate command, and pipe the results back into the
OS/2 session.

This I did, and DPipeLn is the result.

dpipeln [-v] [-f] [-sdos_settings_filename] [-ttemp_dir_name] dos_command
        -v: Start Dos session visible
        -s: Specify file to get Dos Settings from
        -f: Start Dos session in the foreground
        -t: Specify location of temporary files

Now it is possible to call any Dos command-line based tool from an OS/2 prompt,
and to see the results as if it was executed as a native OS/2 command.  Dos
programs can become part of pipelines (though the program must be at the head
of the command line because input is not fed to the Dos program), they can be
called from OS/2 based Make utilities, even from IBM's WorkFrame/2!

DPipeLn even passes return codes back from a terminated Dos program.  This is
essential to allow make utilities to operate correctly.


ΓòÉΓòÉΓòÉ 4.1.2.2. Internals ΓòÉΓòÉΓòÉ

DPipeLn Internals

DPipeLn was developed with the excellent EMX/GCC development system by Eberhard
Mattes.  It is a standalone program; it contains none of the library calls that
require emx.dll or emxlibc.dll.

The executable itself and the kit that contains the files needed to build
DPipeLn can be found in the Zips/ directory that accompanies this issue of
EDM/2.


ΓòÉΓòÉΓòÉ 4.1.2.3. Program Flow ΓòÉΓòÉΓòÉ

DPipeLn Program Flow

Here is what happens when DPipeLn is executed:

 1. Stdout is forced into binary mode.

 2. The command line is processed.  Several variables that control program
    operation are set.

 3. The named pipe used for transferring the stdout (and stderr when 4Dos is in
    use) is created.

 4. The named pipe used for transferring the Dos program return code is
    created.

 5. The StartData structure, which is used by DosStartSession() OS/2 API
    function, is populated with the proper data.

 6. The auxiliary batch file is created.  DosStartSession actually calls the
    Dos command processor and instructs it to execute this batch file.  The
    contents will be explained when this function is reviewed.

 7. DPipeLn executes the DosStartSession call.  The Dos program runs
    asynchronously.

 8. A separate thread is initiated that waits for the return code from the Dos
    program.

 9. DPipeLn connects to the Dos stdout pipe and prints out data that is fed by
    the Dos program through the pipe.

10. We wait for the return code thread to complete.  When it is complete, we
    know the Dos program is complete and we set DPipeLn's return code to be the
    same as the Dos return code.

11. Malloc'ed memory is freed and the named pipes are disconnected.

12. DPipeLn exits with the return code previously set.


ΓòÉΓòÉΓòÉ 4.1.2.4. DPipeLn.c ΓòÉΓòÉΓòÉ

This portion of the article is intended to be an introduction to the relevant
portions of the OS/2 API.  If you are already familiar with the Named Pipe API,
the Session API, and the Thread API, you will probably find it more worth your
while to examine DPipeLn's source code directly to learn about the internals.


ΓòÉΓòÉΓòÉ 4.1.2.5. #defines, #includes, and Global Variables ΓòÉΓòÉΓòÉ

DPipeLn.c

#define INCL_DOSSESMGR    /* Session Manager values */
#define INCL_DOS          /* DOS Calls (not MS-DOS) */
#define INCL_DOSNMPIPES   /* Named Pipe Support */
#define INCL_DOSPROCESS   /* Process IDs */
#define INCL_DOSQUEUES    /* Queue support */

Since the OS/2 header files are so big, there are #ifdefs throughout them that
allow you to tell the compiler only which sections you would like included.
DPipeLn needs to use these sections.

#define BUFSIZE 80        /* Pipe buffer size */
#define SETSIZE 4096      /* Dos settings maximum size */

Like the comments say, make symbolic constants for the named pipe buffer size,
and the size of the Dos settings structure.

#define new_string(x) ((char *)malloc((x) + 1))
#define freemem(x) if ((x) != NULL) free((x))

Macros to make string creation and memory release a little easier.

#define USING_4DOS

When compiling the software, #define this if you are using the 4Dos command
processor replacement.  The reason for this will be discussed later in the
article.

#include <os2.h>
#include <stdio.h>
#include <string.h>
#include <ctype.h>
#include <stdlib.h>

#include the header files that we need.

The following are the function prototypes for the program.  I'm including them
here with a description of what they all do because I won't show and describe
the internals of each function--only the interesting ones.

PBYTE get_dos_settings(char *file);

Read in the Dos settings file.  The Dos settings file lets the user describe
the settings for the Dos session that the indicated program will be run in.
The format of the settings file is documented later in this article.

char *get_basename();

Creates a base name for the named pipes and auxiliary batch file out of the PID
of the DPipeLn process.  The function allocates a string which is freed at the
termination of the program.

char *make_npipename(char *PQbasename);

Takes the passed string and makes an appropriate name for the named pipe
through which the Dos session will communicate with the OS/2 session.

char *make_batname(char *base, char *tempdir);

Makes the auxiliary batch file name.  The function returns a fully-qualified
path.

int build_batchfile(char *Batname, char *Errpname, char *Command);

Builds the auxiliary batch file.  Returns FALSE if the build failed.

void process_cmdline(int argc, char *argv[]);

Processes all the command line switches and sets appropriate global variables
that control the program flow.

void usage();

Prints a usage message, calls cleanup(), then exits.

void cleanup();

Frees allocated memory and disconnects named pipes.

char *get_exename(char *arg);

Strips the path off of argv[0] to make an executable name out of it.  Returns a
character string containing just the name by which DPipeLn was executed.  The
string is used when reporting errors.

void setup_startdata();

DPipeLn calls the OS/2 API function DosStartSession() to create the Dos session
in which the Dos command is run.  DosStartSession() takes a struct called
STARTDATA.  This function puts the proper data in the struct.

void transfer_data(HPIPE *piphand);

This function reads the data from the named pipe that is connected to the Dos
programs stdout (and stderr if 4Dos is the command processor).

void read_errpipe();

This function reads the data from the named pipe that is connected to the
"echo" command in the auxiliary batch file.  It runs in a separate thread and
collects the return code from the Dos program.

char *make_rcdname(char *base);

We need a name for the named pipe that transfers the return code from the Dos
session.  make_rcdname creates a character string that contains the name.

char *get_tempdir();

Scans the environment looking for a suitable temporary directory name.  This
directory will hold the auxiliary batch file.  get_tempdir() returns a
character string with the dirname in it.

Now, global variables:

PSZ    PgmTitle = NULL;    /* Title of window in which Dos program will execute */
PSZ    PgmCmdLine = NULL;  /* Command line for Dos program */
PSZ    PgmSettingsFile = NULL;    /* File containing DOS settings */
PSZ    Exename = NULL;     /* DPipeLn Executable name */
UCHAR  ObjBuf[100];        /* Object buffer.  Used by DosStartSession */
PSZ    Command;            /* The actual DOS command to be executed */
PSZ    Errpname;           /* Name of the pipe that contains the return code */
HPIPE  Piphand, Rcdpipe;   /* Named Pipe handles */
int    Opt_visible;        /* Run DOS session invisibly */
int    Opt_settings;       /* DOS session has a settings file */
int    Opt_foreground;     /* Run session in foreground */
char   *PQbasename;        /* Unique name for the named pipe */
char   *Pname;             /* Fully qualified path for named pipe */
char   *Batname;           /* Unique name of the batch file */
ULONG  OwningPID;          /* PID of dpipeln.exe */
char   RCstring[BUFSIZE];  /* String to temporarily hold ret code from DOS program */
char   *Tempdir = NULL;    /* temporary directory in which to put batch file */


ΓòÉΓòÉΓòÉ 4.1.2.5.1. main() ΓòÉΓòÉΓòÉ

On to the main program.  I'll leave out the local variables and only mention
them when pertinent.  Also, I won't cover each and every statement.  Most are
documented thoroughly within the code if you are interested.

USHORT main(int argc, char *argv[]) {

Standard stuff.

if (_fsetmode(stdout, "b") == -1) {
  fprintf(stderr, "Could not set stdout to binary mode.\n");
  exit(-1);
}

Set stdout to binary mode.  This is necessary because when stdout is in text
mode, EMX converts \n to \r\n on output.  This helps when porting applications
from Unix to OS/2, but is not desired behavior here.

PQbasename = get_basename();
Pname = make_npipename(PQbasename);
Errpname = make_rcdname(PQbasename);
Batname = make_batname(PQbasename, Tempdir);

Now we create unique names for the pipe through which the Dos program will send
it's output, the pipe that will transfer the return code from the Dos program,
and the auxiliary batch file.  All the variables will contain fully qualified
paths to the referenced resources.

rc = DosCreateNPipe(Pname,
      &Piphand,
      NP_ACCESS_DUPLEX,
       NP_WAIT ||
       NP_TYPE_MESSAGE ||
       NP_READMODE_BYTE ||
       NP_UNLIMITED_INSTANCES,
      outbuffer, inbuffer, timeout);
rc = DosCreateNPipe(Errpname,
      &Rcdpipe,
      NP_ACCESS_DUPLEX,
       NP_WAIT ||
       NP_TYPE_MESSAGE ||
       NP_READMODE_BYTE ||
       NP_UNLIMITED_INSTANCES,
      outbuffer, inbuffer, timeout);

Important part--create the named pipes.  The variables refer to the following:

Pname, Errpname
          The names of the pipes.

Piphand, Rcdpipe
          The OS/2 programming reference calls these "Pipe Handles".  These
          were defined in the global variable section, and the API takes
          addresses to them.  The API function then populates them with the
          proper data so they will refer to the named pipe.

NP_ACCESS_DUPLEX
          These will be duplex (two-way) pipes.  For some reason, I was unable
          to get them to function as one-way pipes.

NP_WAIT
          Open the pipe in blocking mode, i.e. DosRead and DosWrite block if
          there is no data available.

NP_TYPE_MESSAGE
          Data is written to the pipe as a stream of messages, as opposed to a
          stream of bytes (NP_TYPE_BYTE).

NP_READMODE_BYTE
          Data is read from the pipe as a stream of bytes.

NP_UNLIMITED_INSTANCES
          There is no limit on the number of instances of this pipe.  This
          parameter doesn't really matter, as we know there will always be no
          more than one of each of these pipes (since the names are unique).

outbuffer, inbuffer, timeout
          These local variables set the size of the output and input buffers
          for the pipes, and set the default amount of time DosWaitNPipe will
          wait for a pipe to become available.

setup_startdata(&sd);

DosStartSession takes a special parameter--a pointer to what is called the
StartData structure.  It contains members that define the different
characteristics of the new session.


ΓòÉΓòÉΓòÉ 4.1.2.5.2. setup_startdata() ΓòÉΓòÉΓòÉ

Here is the definition of the StartData structure, taken from the EMX header
files:

typedef struct {
  USHORT Length;
  USHORT Related;
  USHORT FgBg;
  USHORT TraceOpt;
  PSZ    PgmTitle;
  PSZ    PgmName;
  PBYTE  PgmInputs;
  PBYTE  TermQ;
  PBYTE  Environment;
  USHORT InheritOpt;
  USHORT SessionType;
  PSZ    IconFile;
  ULONG  PgmHandle;
  USHORT PgmControl;
  USHORT InitXPos;
  USHORT InitYPos;
  USHORT InitXSize;
  USHORT InitYSize;
  USHORT Reserved;
  PSZ    ObjectBuffer;
  ULONG  ObjectBuffLen;
} STARTDATA;

void setup_startdata(STARTDATA *SD) {

setup_startdata() takes one parameter--a pointer to a STARTDATA struct.

SD->Length = sizeof(STARTDATA);

First we set the length of the structure.  Different values enable different
properties--specifically a length of 30 or 32 will cause DosStartSession to
leave the rest of the struct blank and allow the installation file to fill in
appropriate fields. We need all the functionality, so we will initialize
SD->Length to the actual size of the struct.

SD->Related = SSF_RELATED_INDEPENDENT;

We want an independent session.  Originally I had this set as
SSF_RELATED_CHILD, because it seem to make sense that I would want DPipeLn to
spawn a child session to run the Dos program in.  Also, child sessions cause a
Termination Queue to be created, which, for Dos sessions, contains the Dos
program's exit code.  Obtaining the exit code is then merely a matter of
invoking the necessary functions from the queue API.  However, the Toolkit
reference says this about SSF_RELATED_CHILD:

Once a process has issued DosStartSession specifying a value of 1 for Related,
no other process within that session can issue related DosStartSession
functions until all the dependent sessions have ended.

And I found that that was true.  When running IBM's WorkFrame/2 from the 11/93
PDK CD-Rom and running a make that involved a Dos compiler and DPipeLn, I could
not start any other tool until the make was finished.  WorkFrame would complain
with error 452 "ERROR_SMG_NOT_PARENT".  Unfortunately, SSF_RELATED_INDEPENDENT
type sessions do not pass exit codes back to the parent.  To circumvent that,
DPipeLn creates a Dos batch file each time it is run.  The batch file contains
batch commands to run the Dos program, and then send the return code back
through the return code pipe to the OS/2 session.  This one of two reasons is
why DPipeLn works better with 4Dos than the stock command.com--4Dos includes
primitives for retrieving the return code from the previously run program.  The
batch file for command.com is several hundred lines of if statements.  The
second reason is that command.com makes no provision for redirecting stderr.
Thus, you get stderr from the Dos process only if you are running 4Dos.

SD->FgBg = Opt_foreground ? SSF_FGBG_FORE : SSF_FGBG_BACK;

Opt_foreground is a global variable set while processing the command line.  It
is true if the user specified on the command line that the Dos session should
appear in the foreground.  FgBg is the element of STARTDATA that controls that
characteristic.

SD->TraceOpt = SSF_TRACEOPT_NONE;

It is possible to start a session specifically for debugging--if so, TraceOpt
is set to SSF_TRACEOPT_TRACE or SSF_TRACEOPT_NOTIFY.

SD->PgmTitle = PgmTitle;

PgmTitle contains the title of the session window.

SD->TermQ = 0;

If the Dos session was a child session, we would set TermQ equal to the queue
handle. 0 indicates that there is no termination queue.  TermQ is ignored for
independent sessions anyway.

SD->InheritOpt = SSF_INHERTOPT_PARENT;

This determines if the new session will inherit the parents environment or not.
In this case, we want to.

SD->SessionType = SSF_TYPE_WINDOWEDVDM;

Though the default is for the session to be invisible, we still want to set its
type to a windowed VDM in case the user shows the window.

SD->IconFile = 0;

There is no icon associated with this session.

SD->PgmHandle = 0;

Do not use the installation file. I'm not sure what this means or how it works.
The CP reference is vague on this parameter.

SD->PgmControl = Opt_visible ? SSF_CONTROL_VISIBLE : SSF_CONTROL_INVISIBLE;

Start the program as visible, or invisible depending on the command line
argument.

SD->InitXPos = 30;
SD->InitYPos = 40;
SD->InitXSize = 200;

Here the initial window coordinates and size are set.

SD->Reserved = 0;

This is a reserved parameter.  The CP reference says it must be 0.

SD->ObjectBuffer = ObjBuf;

DosStartSession calls DosExecProgram to actually start the program.  If
DosExecPgm fails, the name of the object responsible is placed in this buffer.

SD->ObjectBuffLen = 100;

This is just the size of the object buffer.

SD->Environment = Opt_settings ? get_dos_settings(PgmSettingsFile) : 0;

DosStartSession allows Dos sessions to get their settings from a string of
null-terminated strings.  If the user specified a settings file on the command
line, then get_dos_settings() loads that file into memory and Environment is
assigned a pointer to the beginning of the set.  The settings cannot be any
larger than 4096 bytes.  This is not documented in the CP Reference, I learned
how to do it by examining the code from Norm Ross's StartD program.  Thus,
DPipeLn and StartD can use the same settings files.

SD->PgmName = 0;

PgmName is the name of the executable that DosStartSession is running.  If this
is 0 (or NULL) the Session will invoke the a shell--either the one specified in
CONFIG.SYS or the one in the settings file.

PgmCmdLine = new_string(strlen(Batname) + strlen("/c "));
strcpy(PgmCmdLine, "/c ");
strcat(PgmCmdLine, Batname);
SD->PgmInputs = PgmCmdLine;

PgmInputs is the  last of the STARTDATA elements.  It points to the command
line for the program being invoked.  Since we are actually invoking a batch
file that runs the desired executable, we need to run it through the shell,
thus the /c.


ΓòÉΓòÉΓòÉ <hidden> StartD Reference ΓòÉΓòÉΓòÉ

StartD is a small OS/2 utility written by Norm P. Ross (npross@undergrad.
uwaterloo.ca) that starts a Dos session from an OS/2 command line.  It is a lot
like the built-in start /dos , except it allows a settings file to be
specified.  The settings file uses the same strings found in a standard Dos
settings box.  Here's the settings file I use when spawning Borland C/C++ for
Dos.

EMS_MEMORY_LIMIT=128
XMS_MEMORY_LIMIT=8192
DPMI_DOS_API=ENABLED
DPMI_MEMORY_LIMIT=8
IDLE_SENSITIVITY=50

StartD can be found at ftp-os2.nmsu.edu in /pub/os2/2.x/sysutils/startd.zip.


ΓòÉΓòÉΓòÉ 4.1.2.5.3. main() continued ΓòÉΓòÉΓòÉ

Now that the STARTDATA struct is set up, we can create the batch file, and
start the new session.  The session is started asynchronously, so program flow
continues after the call.

rc = build_batchfile(Batname, Errpname, Command);
rc = DosStartSession(&sd, &sess_id, &s_pid);

DosStartSession() will return the new session's ID in sess_id, and the
appropriate process ID in s_pid.

Because DPipeLn might still be busy transferring stdout from the Dos program
when the Dos program ends and sends its return code over the pipe, we need to
wait for that return code in a separate thread.  Starting new threads in OS/2
is easy--almost easier than under Unix:

rc = DosCreateThread(&threadid, read_errpipe, targ, tflags, tstack);

DosCreateThread() needs the following

read_errpipe
          The name of the function to execute in the thread.

targ
          The address of a parameter block to pass to the function.  This
          allows any information to be passed into the thread in the form of a
          pointer to some storage.

tflags
          If true, the thread starts right away.  If false, the program must
          call DosResumeThread() to start the thread.

tstack
          Specifies the amount of stack to give to the thread.  The main
          program sets this at 4096 bytes.

DosCreateThread() returns the thread ID in threadid.

rc = DosConnectNPipe(Piphand);

After creating the pipe, we need to connect to it.

transfer_data(&Piphand);

And now we transfer data from it.  transfer_data() loops until the Dos program
closes the pipe (by exiting).  The data is gathered out of the pipe by a
DosRead() call and printed to the stdout of the OS/2 session.

rc = DosWaitThread(&threadid, DCWW_WAIT);

This waits for the read_errpipe() thread to complete.  When it is complete we
know that the Dos program (actually the batch file) has reported the exit code.
This is the easy way out--normally in a multithreaded program semaphores are
used to insure that global variables are accessed only when the data in them is
valid.

sscanf(RCstring, "%d", &dosreturn);

Put the return code into the local dosreturn. The batch file transmits the code
as ASCII text, so the sscanf is necessary to convert it to an integer.

DosWaitChild(DCWA_PROCESS,
      DCWW_WAIT,
      &wp_results,
      &the_pid,
      s_pid);

This call may not be absolutely necessary, since the Dos program is started as
an independent session.  It blocks until the Dos session is complete.

cleanup();

cleanup() frees allocated storage and closes the named pipes.

return (USHORT)dosreturn;

Lastly, return the Dos exit code to the calling process.


ΓòÉΓòÉΓòÉ 4.1.2.6. DPipeLn Examples ΓòÉΓòÉΓòÉ

Now that you understand how DPipeLn works, let's look at a couple of ways to
use it.


ΓòÉΓòÉΓòÉ 4.1.2.6.1. Make and DPipeLn ΓòÉΓòÉΓòÉ

Here is a makefile I use that utilizes DPipeLn.  Note that GnuMake supports
parallel makes, and since OS/2 never loads code more than once, parallel makes
can be a real win even with Dos compilers.

SHELL=c:/4os2/4os2.exe

# Makefile for the School Improvement Program.

OBJS=fileio.obj filewins.obj prutils.obj si_chk0.obj si_chk1.obj si_chk2.obj \
si_chk3.obj si_chk4.obj si_chk5.obj si_chk6.obj si_chk7.obj si_chk8.obj \
si_chk9.obj si_chka.obj si_chkb.obj si_chkc.obj si_chkd.obj si_chke.obj \
si_chkf.obj si_chkg.obj si_chkh.obj si_pg0.obj  si_pg1.obj si_pg2.obj \

OBJS2=d:\dosapps\borlandc\lib\c0l.obj

CFLAGS=-ml -c -If:\tcxl55\inc

DEBUGLINK= /m /v

DEBUG=-v
%.obj : %.c
    echos $< ^ >> sources.rsp

sip.exe: preclean objects $(OBJS) sip.rsp
    dpipeln.exe -sbcc.ini tlink.exe $(DEBUGLINK) /c @sip.rsp,sip,sip,tcxlbcl cl

objects: $(OBJS)
    dpipeln.exe -sbcc.ini bcc.exe $(DEBUG) $(CFLAGS) @sources.rsp

sip.rsp: makefile
    echo $(OBJS2) + > sip.rsp
    echo $(OBJS) >> sip.rsp

preclean:
    copy nul sources.rsp

clean:
    erase /q sip.exe sources.rsp sip.rsp $(OBJS)

The makefile builds a list of targets in the file sources.rsp, and then passes
that to BCC as a response file.  BCC only loads itself once, but you could
speed up processing by splitting the object files up into two targets and
compiling them in parallel.


ΓòÉΓòÉΓòÉ 4.1.2.7. WF/2 and DPipeLn ΓòÉΓòÉΓòÉ

If you have IBM's WorkFrame/2 and have read its README file, you may remember
that it says that you can use Dos hosted tools, but you cannot see their
output. With DPipeLn, you can!  Dos command-line tools become just like OS/2
tools under WF/2.

Under Language Profile Management, simply specify x:\path\dpipeln.exe as the
compiler executable name. Then, under Compiler Options, type the acual name of
the compiler, along with any command-line options, in the options dialog.
Here's an example using Turbo Pascal 6.0 for Dos.

And in the Compiler Options dialog box:

...


ΓòÉΓòÉΓòÉ 4.1.3. Conclusion ΓòÉΓòÉΓòÉ

DPipeLn has been a very useful tool for helping to seamlessly integrate my Dos
development utilities with OS/2 hosted utilities such as GnuMake, IBM WF/2, and
others.  Source and executable is available, as mentioned at the beginning of
this article.

Comments, questions, and suggestions are encouraged.  I may be reached at the
address found at the end of this document.

Happy Hacking!


ΓòÉΓòÉΓòÉ 4.2. OS/2 Installable File Systems - Part 1 ΓòÉΓòÉΓòÉ

                                OS/2 Installable
                                  File Systems

                              Part 1 - Introduction

                                  Andre Asselin
                                ([e-mail])


ΓòÉΓòÉΓòÉ 4.2.1. Introduction ΓòÉΓòÉΓòÉ

One of the most useful but obscure features of OS/2 is it's support for
installable file systems (IFSs). This API allows you to extend OS/2 to do two
things: access files stored on disk in formats other than FAT and HPFS,  and
access files that are stored on a network file server.  For example, under many
versions of UNIX, files are stored in the Berkeley fast file system format,
which isn't compatible with FAT or HPFS.  If you have both UNIX and OS/2
installed on the same computer with partitions setup for each, you could write
an IFS to read and write the UNIX files while OS/2 is running and give all the
programs running under OS/2 (including DOS and Windows programs) access to
those files.

The other variety of IFS is called a remote file system or redirector, and
allows file sharing over LANs.  In this case, when a program calls for a file,
the IFS acts as a client and sends the request over a network to a file server.
The file server handles the request and sends the data back to the client.
Examples of this type of IFS include Novell's Netware requester and the
requester part of LAN Server.  Sometimes, in addition to just sending the
requests to the server, this type of IFS also has to translate between OS/2
file conventions and file conventions that the server understands.  For
example, the NFS (Network File System) protocol is completely UNIX oriented, so
the NFS client (which is an IFS) has to handle UNIX conventions like case
sensitive filenames and UNIX file attributes.

Up until now, there hasn't been much written on how to develop an IFS. It also
doesn't help that the documentation on the IFS API has been available only by
special request from IBM.  This series is going to explore the IFS API in depth
with working examples in order to take the mystery out of writing them.  This
first article is a brief overview of the IFS concept to give a feel for what's
involved in writing one.  In the coming months, I'm going to explore the IFS
architecture in depth and build up a toolkit that can be used as a skeleton for
writing an IFS.


ΓòÉΓòÉΓòÉ 4.2.2. IFS Structure and How It Fits In ΓòÉΓòÉΓòÉ

An IFS (which is also known as an FSD for File System Driver) can  be thought
of as a specialized kind of physical device driver (PDD), although it is
structured very differently.  Instead of having only two entry points and being
based on request packets, it is structured as an ordinary 16-bit DLL with a
series of predefined entry points, broken up into four groups,  that are
exported to the system (see Table 1). The first group consists of the primary
entry points that all IFSs are required to export.  This group does basic file
manipulation, such as opening and closing, and reading and writing files.  Most
of these entry points correspond pretty closely in name and function to related
DosXxx calls. The other three groups of calls provide support for the swapper,
file locking, and UNC (Universal Naming Convention). For each of these groups,
if your IFS doesn't support that particular feature, you don't have to export
any of the functions in that group of entry points. Note that exports should be
made on a group-by-group basis; don't export only some of the entry points from
a group.

Figure 1 (below) shows where an IFS fits into the OS/2 system.  The two shaded
components are what make up an IFS.  The piece that runs in ring 0 (called
MY.IFS in the figure) is the main component.  It is called by the OS/2 kernel
through one of its FS_XXX entry points whenever something needs to be done on a
drive that the IFS is managing.  The IFS performs the function and returns the
requested data or an error code.  Typically, it will interact with a PDD to do
its I/O.  Like any ordinary DLL, an IFS doesn't have a process or threads of
its own.  Instead, it operates in the context of the caller's process and on
the caller's thread (in the case of an IFS, the caller's thread and process are
the thread and process of the application making the Doscall). In this sense,
an IFS can be thought of as a passive library that's not activated until a
program calls it.

Since an IFS has to be available to every application in the system, it is
loaded into global system memory (using GDT selectors).  Any memory it
allocates (such as for buffers) should also come from global system memory so
that no matter which process its entered from, it'll still have access to the
memory.

The piece that runs in ring 3 (UMY.DLL in the figure) is a utility library.
There is one utility DLL for each IFS; the naming convention is a 'U' followed
by the IFS name with an extension of .DLL.  It has four entry points; one each
for FORMAT, RECOVER, SYS, and CHKDSK.  When a user runs any of those programs
and it detects that it is being run against a drive being managed by an IFS, it
will call the appropriate entry point in the IFS's utility DLL.  The DLL is
then completely responsible for carrying out the command.


ΓòÉΓòÉΓòÉ 4.2.3. How a Doscall Gets Processed ΓòÉΓòÉΓòÉ

A typical Doscall (such as DosOpen, DosRead, or DosWrite) is processed mainly
by the IFS with some help from the OS/2 kernel (see Figure 2).  When an
application issues a Doscall, such as DosOpen (1), a component of the OS/2
kernel called the file system router does some preliminary validation of the
parameters.  If everything's OK, it decides which IFS the call should be sent
to and calls the IFS at the appropriate entry point, which in the case of
DosOpen is FS_OPENCREATE (2).  The IFS then looks at the parameters that were
passed and decides on a course of action to service the call.  In some cases,
it may not support the function (for example, trying to open a remote drive for
direct, sector-by-sector access), in which case it immediately returns an error
code.  If it does support the function, it might first check its cache to see
if it already has the requested data, in which case it can just return it.  If
it doesn't have the data in its cache, it will probably have to do some I/O to
get it.

In the this case, it calls one of OS/2's file system helpers, FSH_DOVOLIO (3),
which acts as an intermediary between the IFS and the device driver.
FSH_DOVOLIO generates a request packet and calls the strategy entry point of
the appropriate device driver (4).  The device driver performs the I/O (5), and
eventually returns to FSH_DOVOLIO, which returns back to the IFS. The IFS can
then examine the return code for errors and take appropriate action.  If it
needs to, the IFS can the device driver multiple times until it has all the
requested data.  It then returns back to the OS/2 kernel, which in turn returns
back to the application.  The application can then examine the return code to
see if the operation was successful.


ΓòÉΓòÉΓòÉ 4.2.4. Ring 0 Issues ΓòÉΓòÉΓòÉ

The type of IFS described above runs completely in ring 0 and can be thought of
as a 'traditional' IFS.  Unfortunately, it can be difficult to develop because
of the restrictions placed on code that runs at ring 0 (PDDs and VDDs suffer
from these restrictions as well).  There are three main restrictions:

No preemptive multitasking - When an IFS or any other ring 0 code is entered,
preemptive multitasking is temporarily disabled.  The IFS can still yield to
other threads (i.e. cooperative multitasking), but it will never be suspended
unless it specifically asks for it.  This has the benefit of eliminating some
synchronization issues, but it also means that periodic yields have to be
sprinkled throughout lengthy operations.

No Doscalls; only file system helpers and DevHlps - None of the ring 3 API's
(such as the Doscalls) are available to ring 0 code (except at initialization,
which is special).  If you use any functions from the C library, you have to
make sure that they don't in turn use any of the Doscalls (i.e. malloc and free
don't work at ring 0 because they call DosAllocMem).  As a partial replacement,
there are a series of file system helper (FSH) calls available for IFS's (see
Table 2) as well as the standard DevHlp calls available to all device drivers.
These APIs perform common tasks such as allocating memory and handling
semaphores, but they are more primitive and thus more difficult to use than the
Doscalls.

Debugging is a pain - If you thought debugging PM applications was tricky, wait
until you try an IFS! First, you won't be able to use your favorite debugger--
you have to use a ring 0 debugger, such as the OS/2 kernel debugger or ASDT32.
Neither of these can do source level debugging, so you have to know assembler,
and they also have limited support for labels.  There is also no such thing as
a printf in ring 0, so you have to use a hex dump to look at variables.  As if
that weren't bad enough, OS/2's crash protection doesn't apply to ring 0 code;
if your code has a bug and traps, it will bring down the system with an IPE
(Internal Processing Error). This is where you get the blue screen, lots of
register information, a suggestion to call IBM, etc.  Frequent reboots tend to
be the way of life.


ΓòÉΓòÉΓòÉ 4.2.5. The Split IFS / Control Program Approach ΓòÉΓòÉΓòÉ

Because of these restrictions, a popular approach to developing an IFS is to
split it between ring 0 and ring 3.  The ring 0 piece (the IFS proper) contains
only stub routines and passes all the calls up to a ring 3 control program.
The control program handles the calls and then passes the results back to the
ring 0 piece.  The advantages of doing it this way are that developing the bulk
of the IFS is easier (because it runs at ring 3, you don't have to worry about
those restrictions mentioned above), and you have access to all the normal ring
3 APIs.  This approach also allows you to layer an IFS on top of an already
existing IFS; for example, DCF/2 and Stacker for OS/2 probably take this
approach to use FAT or HPFS to store their compressed data files.  This way
they don't have to worry about totally rewriting the FAT or HPFS code-- all
they have to be concerned with is compressing the data on the fly and then
using the already existing IFSs to actually store it on the disk.

This type of IFS is usually implemented using captive threads.  Figure 3 traces
a call as it winds its way between an application, the IFS, and its control
program.  When the control program initializes, it creates one or more threads
that call into the IFS (1 and 2).  The IFS makes these threads block until some
application calls the IFS with work to do (3 and 4).  The IFS then sets up a
parameter area, blocks the application's thread and unblocks the control
program's thread.  The IFS returns back to the control program (5 and 6), where
it executes the request.  The control program then puts the results back in the
parameter block and calls the IFS again (7 and 8).  The IFS then unblocks the
application's thread and has it return with the results (9 and 10) while the
control program's thread is again blocked waiting for a new request.


ΓòÉΓòÉΓòÉ 4.2.6. What's Ahead ΓòÉΓòÉΓòÉ

Well, that's a high level overview of what's involved in writing an installable
file system.  In the next issue, I'm going to start developing the framework to
implement a split ring 0 / ring 3 IFS.  To illustrate how to use it, I'm going
to write an IFS that supports file versions (like VMS).

While you're waiting for the next issue, you may want to start gathering the
tools necessary to write an IFS.  The first thing you'll need, of course, is
the documentation on the IFS API and the libraries and header files that go
along with it.  To get it, you need to send a note on CompuServe requesting the
IFS documentation to Mike Abrams (72420,216) in the OS2DF1 forum section 11
(Device Driver Development) with your name and address.  If you don't have an
account on CompuServe, you can send him a note using the Internet; address it
to [e-mail] (note the period instead of the comma in the
number).

You'll also need two C compilers.  For the ring 0 piece, you'll need a 16-bit C
compiler.  Most IFS developers use Microsoft C 6.0, but I'm going to
investigate the possibility of using Borland C++ instead.  If I can make it
work, that's what I'm going to use, but the code should be compatible with both
compilers.  For the ring 3 piece, you'll need a 32-bit compiler, such as IBM's
C Set++ or Borland C++ for OS/2.  Finally, you probably won't need it right
away, but you should also get a hold of either the kernel debugger or ASDT32,
which is available through IBM's EWS program.

If this series is interesting to you, please drop me a note telling me a little
bit about yourself and your background so that I have a better idea who my
audience is (it'll also help my motivation if I know that more than Steve and I
are reading this series).  While you're at it, if you have any feedback or
ideas on what you'd like to see covered in future articles, I'd love to hear
it.  See you next month.


ΓòÉΓòÉΓòÉ 4.2.7. Table 1 - FSD Entry Points ΓòÉΓòÉΓòÉ

ΓöîΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÉ
ΓöéPrimary Entry Points                                                              Γöé
Γöé                                                                                  Γöé
ΓöéFile Management                                                                   Γöé
Γöé                                                                                  Γöé
Γöé                     FS_OPENCREATE             Open or create a file              Γöé
Γöé                                                                                  Γöé
Γöé                     FS_CLOSE                  Close a file                       Γöé
Γöé                                                                                  Γöé
Γöé                     FS_READ                   Read data from a file              Γöé
Γöé                                                                                  Γöé
Γöé                     FS_WRITE                  Write data to a file               Γöé
Γöé                                                                                  Γöé
Γöé                     FS_CHGFILEPTR             Change the current position in a   Γöé
Γöé                                               file                               Γöé
Γöé                                                                                  Γöé
Γöé                     FS_COMMIT                 Write all cached data for a file toΓöé
Γöé                                               disk                               Γöé
Γöé                                                                                  Γöé
Γöé                     FS_DELETE                 Delete a file                      Γöé
Γöé                                                                                  Γöé
Γöé                     FS_NEWSIZE                Change the size of a file          Γöé
Γöé                                                                                  Γöé
Γöé                     FS_MOVE                   Move or rename a file              Γöé
Γöé                                                                                  Γöé
Γöé                     FS_COPY                   Copy a file                        Γöé
Γöé                                                                                  Γöé
Γöé                     FS_FILEATTRIBUTE          Set or return the standard (DOS)   Γöé
Γöé                                               attributes                         Γöé
Γöé                                                                                  Γöé
Γöé                     FS_FILEIO                 Perform an atomic read/write/lock  Γöé
Γöé                                               operation                          Γöé
Γöé                                                                                  Γöé
Γöé                     FS_FILEINFO               Set or return information on an    Γöé
Γöé                                               open file                          Γöé
Γöé                                                                                  Γöé
Γöé                     FS_PATHINFO               Set or return information on a fileΓöé
Γöé                                                                                  Γöé
ΓöéVolume Management                                                                 Γöé
Γöé                                                                                  Γöé
Γöé                     FS_ATTACH                 Associate or disassociate a drive  Γöé
Γöé                                               letter with an FSD                 Γöé
Γöé                                                                                  Γöé
Γöé                     FS_MOUNT                  Examine a volume to determine if   Γöé
Γöé                                               the FSD knows its format           Γöé
Γöé                                                                                  Γöé
Γöé                     FS_FSINFO                 Get/Set file system information    Γöé
Γöé                                                                                  Γöé
Γöé                     FS_FLUSHBUF               Write all cached data for a volume Γöé
Γöé                                               to disk                            Γöé
Γöé                                                                                  Γöé
ΓöéDirectory Management                                                              Γöé
Γöé                                                                                  Γöé
Γöé                     FS_CHDIR                  Change directory                   Γöé
Γöé                                                                                  Γöé
Γöé                     FS_MKDIR                  Make a new directory               Γöé
Γöé                                                                                  Γöé
Γöé                     FS_RMDIR                  Remove a directory                 Γöé
Γöé                                                                                  Γöé
ΓöéDirectory Search                                                                  Γöé
Γöé                                                                                  Γöé
Γöé                     FS_FINDCLOSE              End a search in progress           Γöé
Γöé                                                                                  Γöé
Γöé                     FS_FINDFIRST              Begin a new search                 Γöé
Γöé                                                                                  Γöé
Γöé                     FS_FINDFROMNAME           Restart a search from a particular Γöé
Γöé                                               point                              Γöé
Γöé                                                                                  Γöé
Γöé                     FS_FINDNEXT               Return next file name              Γöé
Γöé                                                                                  Γöé
Γöé                     FS_FINDNOTIFYCLOSE        Stop monitoring a directory for    Γöé
Γöé                                               changes                            Γöé
Γöé                                                                                  Γöé
Γöé                     FS_FINDNOTIFYFIRST        Start monitoring a directory file  Γöé
Γöé                                               changes                            Γöé
Γöé                                                                                  Γöé
Γöé                     FS_FINDNOTIFYNEXT         Return the next set of changes     Γöé
Γöé                                                                                  Γöé
ΓöéFSD Extended                                                                      Γöé
ΓöéInterface                                                                         Γöé
Γöé                                                                                  Γöé
Γöé                     FS_FSCTL                  Extended interface to an FSD       Γöé
Γöé                                                                                  Γöé
Γöé                     FS_IOCTL                  I/O control for devices            Γöé
Γöé                                                                                  Γöé
ΓöéMiscellaneous                                                                     Γöé
Γöé                                                                                  Γöé
Γöé                     FS_NMPIPE                 Support named pipe operations      Γöé
Γöé                                                                                  Γöé
Γöé                     FS_PROCESSNAME            Allow an FSD to canonicalize a fileΓöé
Γöé                                               name to its own particular         Γöé
Γöé                                               conventions                        Γöé
Γöé                                                                                  Γöé
Γöé                     FS_SETSWAP                Designate a partition as the swap  Γöé
Γöé                                               partition                          Γöé
Γöé                                                                                  Γöé
Γöé                     FS_INIT                   Initialize the FSD                 Γöé
Γöé                                                                                  Γöé
Γöé                     FS_SHUTDOWN               Notify the FSD that the system is  Γöé
Γöé                                               shutting down                      Γöé
Γöé                                                                                  Γöé
Γöé                     FS_EXIT                   Notify the FSD that a process is   Γöé
Γöé                                               ending                             Γöé
Γöé                                                                                  Γöé
ΓöéSwapper Entry Points                                                              Γöé
Γöé                                                                                  Γöé
Γöé                     FS_ALLOCATEPAGESPACE      Allocate space in the swapper file Γöé
Γöé                                                                                  Γöé
Γöé                     FS_DOPAGEIO               Read or write page(s) to the       Γöé
Γöé                                               swapper file                       Γöé
Γöé                                                                                  Γöé
Γöé                     FS_OPENPAGEFILE           Open the swapper file              Γöé
Γöé                                                                                  Γöé
ΓöéFile Locking Entry                                                                Γöé
ΓöéPoints                                                                            Γöé
Γöé                                                                                  Γöé
Γöé                     FS_CANCELLOCKREQUEST      Cancels a lock request             Γöé
Γöé                                                                                  Γöé
Γöé                     FS_FILELOCKS              Lock or unlock a region of a file  Γöé
Γöé                                                                                  Γöé
ΓöéUNC Entry Point                                                                   Γöé
Γöé                                                                                  Γöé
Γöé                     FS_VERIFYUNCNAME          Determine if FSD provides access toΓöé
Γöé                                               a specific UNC server              Γöé
ΓööΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÿ


ΓòÉΓòÉΓòÉ 4.2.8. Table 2 - File System Helpers ΓòÉΓòÉΓòÉ

ΓöîΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÉ
ΓöéFSH_ADDSHARE                        Add a name to the sharing set      Γöé
Γöé                                                                       Γöé
ΓöéFSH_CALLDRIVER                      Call a PDD's extended strategy     Γöé
Γöé                                    entry point                        Γöé
Γöé                                                                       Γöé
ΓöéFSH_CANONICALIZE                    Convert a filename to canonical    Γöé
Γöé                                    form                               Γöé
Γöé                                                                       Γöé
ΓöéFSH_CHECKEANAME                     Verify correctness of an EA name   Γöé
Γöé                                                                       Γöé
ΓöéFSH_CRITERROR                       Signal a hard error                Γöé
Γöé                                                                       Γöé
ΓöéFSH_DEVIOCTL                        Send a PDD an IOCTL request        Γöé
Γöé                                                                       Γöé
ΓöéFSH_DOVOLIO                         Call a PDD to transfer sectors     Γöé
Γöé                                                                       Γöé
ΓöéFSH_FINDCHAR                        Find first occurrence of a         Γöé
Γöé                                    character in a string              Γöé
Γöé                                                                       Γöé
ΓöéFSH_FINDDUPHVPB                     Locates equivalent hVPBs           Γöé
Γöé                                                                       Γöé
ΓöéFSH_FORCENOSWAP                     Forces a segment permanently into  Γöé
Γöé                                    memory                             Γöé
Γöé                                                                       Γöé
ΓöéFSH_GETPRIORITY                     Get current thread's priority      Γöé
Γöé                                                                       Γöé
ΓöéFSH_GETVOLPARM                      Get data for current volume        Γöé
Γöé                                                                       Γöé
ΓöéFSH_INTERR                          Signal an Internal Processing ErrorΓöé
Γöé                                                                       Γöé
ΓöéFSH_IOBOOST                         Give the current thread an I/O     Γöé
Γöé                                    boost                              Γöé
Γöé                                                                       Γöé
ΓöéFSH_IOSEMCLEAR                      Clear an I/O event semaphore       Γöé
Γöé                                                                       Γöé
ΓöéFSH_ISCURDIRPREFIX                  Check if current directory is a    Γöé
Γöé                                    prefix of a file name              Γöé
Γöé                                                                       Γöé
ΓöéFSH_LOADCHAR                        Load character from a string (NLS) Γöé
Γöé                                                                       Γöé
ΓöéFSH_NAMEFROMSFN                     Retrieve a file's name from its    Γöé
Γöé                                    file handle number                 Γöé
Γöé                                                                       Γöé
ΓöéFSH_PREVCHAR                        Move one character backwards in a  Γöé
Γöé                                    string (NLS)                       Γöé
Γöé                                                                       Γöé
ΓöéFSH_PROBEBUF                        Verify a region of memory for      Γöé
Γöé                                    accessibility                      Γöé
Γöé                                                                       Γöé
ΓöéFSH_QSYSINFO                        Retrieve system information        Γöé
Γöé                                                                       Γöé
ΓöéFSH_REGISTERPERFCTRS                Register the IFS with PERFVIEW     Γöé
Γöé                                                                       Γöé
ΓöéFSH_REMOVESHARE                     Remove a name from the sharing set Γöé
Γöé                                                                       Γöé
ΓöéFSH_SEGALLOC                        Allocate a segment                 Γöé
Γöé                                                                       Γöé
ΓöéFSH_SEGFREE                         Deallocate a segment               Γöé
Γöé                                                                       Γöé
ΓöéFSH_SEGREALLOC                      Reallocate a segment               Γöé
Γöé                                                                       Γöé
ΓöéFSH_SEMCLEAR                        Clear a semaphore                  Γöé
Γöé                                                                       Γöé
ΓöéFSH_SEMREQUEST                      Request a semaphore                Γöé
Γöé                                                                       Γöé
ΓöéFSH_SEMSET                          Set a semaphore                    Γöé
Γöé                                                                       Γöé
ΓöéFSH_SEMSETWAIT                      Set a semaphore and wait on it     Γöé
Γöé                                                                       Γöé
ΓöéFSH_SEMWAIT                         Wait on a semaphore                Γöé
Γöé                                                                       Γöé
ΓöéFSH_SETVOLUME                       Force a volume to be mounted on a  Γöé
Γöé                                    drive                              Γöé
Γöé                                                                       Γöé
ΓöéFSH_STORECHAR                       Store a character in a string (NLS)Γöé
Γöé                                                                       Γöé
ΓöéFSH_UPPERCASE                       Uppercase a string (NLS)           Γöé
Γöé                                                                       Γöé
ΓöéFSH_WILDMATCH                       Match a filename using wildcards   Γöé
Γöé                                                                       Γöé
ΓöéFSH_YIELD                           Yield the CPU to higher priority   Γöé
Γöé                                    threads                            Γöé
ΓööΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÿ


ΓòÉΓòÉΓòÉ 4.3. Programming the Container Control - Part 1 ΓòÉΓòÉΓòÉ

                                 Programming the
                                Container Control

                               Larry Salomon, Jr.
                               ([e-mail])


ΓòÉΓòÉΓòÉ 4.3.1. Introduction ΓòÉΓòÉΓòÉ

The release of OS/2 2.0 was special in many ways; not the least was the
inclusion of four new standard PM controls:  the container, the notebook, the
slider, and the value set.  Without question, the most difficult of these to
utilize fully is the container control.  It's flexible design allowed for it to
be used in a variety of fashions (which is no surprise when you look at its
real-world counterpart) and provided a CUA 91 compliant interface without much
additional work by the programmer.  Unfortunately, the initial work that has to
be done is significant and has daunted many developers.

This article begins a multi-part series on how to program the container and
will describe the container control from a developer's perspective as well as
introduce some of the basic programming concepts that can be used in you
applications.  For additional information, it is highly recommended that you
acquire a copy of the Winter and Spring 1993 issues of the OS/2 Developer
magazine (produced by IBM Corp. and published by Miller Freeman Inc.).  These
two issues contain a single article each by the container control developers on
how to use it and are both very informative.


ΓòÉΓòÉΓòÉ 4.3.2. A Bird's-Eye View ΓòÉΓòÉΓòÉ

In "real-life" a container is something that you see everyday. Most people
store foodstuffs in Tupperware containers.  On many office desks, pens and
pencils are stored in containers.  In a filing cabinet, documents are stored in
another container, although it is more widely known as a folder. Everywhere you
look, there are containers being used; because of this, the CUA designers
decided that the ability to store objects in a container was a very good thing;
not only was it a familiar concept, but it was also already being used on
another computer platform (the MacIntosh) with extremely good results.

The container is exactly what you think it is.  It allows an application to
place "things" inside of it and these things can be viewed in one of five
different ways.  The term "thing" is used because the container does not
restrict the application in the type of items stored.  The five different views
supported by the container are listed below:

View                Description
Icon                Each object is represented as an icon with a descriptive
                    string below it.
Name                Each object is represented as an icon with a descriptive
                    string to the right.
Text                Each object is represented solely as a descriptive string.
Tree                Each object is represented as a hierarchical diagram of
                    icons and/or descriptive strings.
Detail              Each object is represented as a detailed description of the
                    object.  The information displayed is defined by the
                    application.

This month, we will only employ the icon view for simplicity.  The other views
will be covered in subsequent months.

Each object is described to the container using a base data type - this can be
either the RECORDCORE or the MINIRECORDCORE structure, depending on the CCS_
style used when creating the control. (For the purposes of our discussion, the
MINIRECORDCORE structure will be referenced although either could be used.)
When objects are allocated, additional memory at the end of the MINIRECORDCORE
structure can be requested, for the storage of any object-specific data. Thus,
you would have to define a structure to contain both the base data and the
additional fields needed:

typedef struct _MYCNRREC {
   MINIRECORDCORE mrcCore;
   CHAR achText[256];
   ULONG ulNumSold;
   float fGrossIncome;
   float fNetIncome;
   float fTotalCost;
   float fNetProfit;
} MYCNRREC, *PMYCNRREC;

Since the container, when returning pointers to the object records, always
returns a PRECORDCORE type, you will need to typecast this to your
application-defined type (here, PMYCNRREC).


ΓòÉΓòÉΓòÉ 4.3.3. Basic Record Operations ΓòÉΓòÉΓòÉ

Inserting and Removing Records

The container makes a distinction between allocation and insertion of records;
likewise, a similar distinction is made between removing a record and freeing
the memory consumed by the record.  Allocation is accomplished by sending the
control a CM_ALLOCRECORD message, while insertion is done by sending a
CM_INSERTRECORD message.

The CM_ALLOCRECORD requires the number of additional bytes needed in mpParm1
and the number of records to allocate in mpParm2.  If more than one record is
allocated, a linked list of the records is returned (with the linked being the
preccNextRecord field in the MINIRECORDCORE structure); otherwise, a pointer to
the record is returned.  The container will initialize the entire structure to
"nothing" (meaning no icon, no text, etc.).  It is your responsibility to
"fill-in-the-blanks" so that something meaningful will appear in the control;
for the icon view, these fields are the hptrIcon and pszIcon fields of the
MINIRECORDCORE structure.  You should set them to the handle of the icon and to
the pointer to the descriptive text to be displayed, respectively.  Using our
MYCNRREC structure again as an example:

ULONG ulExtra;
PMYCNRREC pmcrRecord;

ulExtra=sizeof(MYCNRREC)-sizeof(MINIRECORDCORE);

pmcrRecord=(PMYCNRREC)PVOIDFROMMR(WinSendMsg(hwndCnr,
                                             CM_ALLOCRECORD,
                                             MPFROMLONG(ulExtra),
                                             MPFROMSHORT(1)));
if (pmcrRecord!=NULL) {
   pmcrRecord->mrcCore.hptrIcon=WinLoadPointer(HWND_DESKTOP,
                                               NULLHANDLE,
                                               HPTR_PRODUCT);
   pmcrRecord->mcrCore.pszIcon=pmcrRecord->achText;
   strcpy(pmcrRecord->achText,"Thing-A-Ma-Jig");
} /* endif */

Once you have allocated, initialized, and are ready to insert your records, you
need to describe the placement of the records to the container (via the
RECORDINSERT structure) to the container.  An item of interest is that the
container has two notions of order:  z-order and item-order. The former should
be familiar because PM windows all have this concept.  The latter, however, is
useful when you wish to enumerate the records in an order other than the
z-order placement without affecting the appearance of the records in the
container.  Continuing our example above:

RECORDINSERT riInsert;

riInsert.cb=sizeof(RECORDINSERT);
riInsert.pRecordOrder=CMA_FIRST;    /* Insert at the head of the list */
riInsert.pRecordParent=NULL;        /* No parent record */
riInsert.fInvalidateRecord=TRUE;    /* Automatic invalidation of records */
riInsert.zOrder=CMA_TOP;            /* Place on top of siblings */
riInsert.cRecordsInsert=1;

WinSendMsg(hwndCnr,
           CM_INSERTRECORD,
           MPFROMP(pmcrRecord),
           MPFROMP(&riInsert));

A couple of important things should be noted here:

o It is very inefficient to allocate and insert records one at a time.  If at
  all possible, allocate many records and insert them all at once.
o You can specify FALSE for the fInvalidateRecord field to cause the container
  not to invalidate the records once they are inserted.  Doing this allows you
  to reflow - or arrange - the records in the container before displaying them
  ( using the CM_ARRANGE) message.  If you choose to do this, you must send a
  CM_INVALIDATERECORD message specifying CMA_REPOSITION and CMA_ERASE to redraw
  the container.

To remove a record from the list, you use the CM_REMOVERECORD message.  If you
choose not to have the container free the memory (using the CMA_FREE flag), you
must also send a CM_FREERECORD message to return the memory to the system.  A
"gotcha" here is that the first parameter of the two messages is a pointer to
an array of pointers. Thus, if you are only removing one record, you need to
specify a pointer to the record pointer:

PMYCNRREC pmcrRecord;

/* Query the first record in the container */
pmcrRecord=(PMYCNRREC)PVOIDFROMMR(WinSendMsg(hwndCnr,
                                             CM_QUERYRECORD,
                                             MPFROMP(NULL),
                                             MPFROM2SHORT(CMA_FIRST,
                                                          CMA_ITEMORDER)));

/* Remove it and free the memory */
WinSendMsg(hwndCnr,
           CM_REMOVERECORD,
           MPFROMP(&pmcrRecord),
           MPFROMSHORT(CMA_FREE));

/* We now need to invalidate the container */
WinSendMsg(hwndCnr,
           CM_INVALIDATERECORD,
           MPFROMP(NULL),
           MPFROM2SHORT(0,CMA_REPOSITION|CMA_ERASE));

Arranging the Records

Arranging the records is as simple as sending a CM_ARRANGE message.  This
message takes no parameters. the record pointer:

WinSendMsg(hwndCnr,
           CM_ARRANGE,
           0,
           0);


ΓòÉΓòÉΓòÉ 4.3.4. Using the CM_SETCNRINFO Message ΓòÉΓòÉΓòÉ

To change the value any of a multitude of attributes belonging to the
container, you can use the CM_SETCNRINFO message.  This controls everything
about the container including the current view type, which is probably its most
widely used feature.  The way this message works is that you define a variable
of type CNRINFO, set the appropriate fields, and send the message.  In the
second parameter, you specify one or more flags which tells the container which
fields to examine.  Thus, you do not have to initialize the entire structure
for one field. the record pointer:

CNRINFO ciInfo;

/* Change the view to icon view */
ciInfo.flWindowAttr=CV_ICON;

WinSendMsg(hwndCnr,
           CM_SETCNRINFO,
           MPFROMP(&ciInfo),
           MPFROMLONG(CMA_FLWINDOWATTR));

This provides a very limited example of the CM_SETCNRINFO message.  For more
information about the CNRINFO structure see the Technical Reference, available
with the Programming Toolkit.


ΓòÉΓòÉΓòÉ 4.3.5. Basic Notifications ΓòÉΓòÉΓòÉ

The container will notify its owner via the WM_CONTROL message whenever any of
a multitude of events occur.  Five of the more basic notifications are listed:

Code                Meaning
CN_ENTER            The user pressed ENTER or double clicked the mouse while
                    the container had the focus.
CN_HELP             The user pressed F1 while the container had the focus.
CN_CONTEXTMENU      The user pressed the context menu key combination as
                    defined on the System settings.  The default for the system
                    is Ctrl+F10.
CN_SETFOCUS         The container has received the focus.
CN_KILLFOCUS        The container is losing the focus.

Next month we'll briefly describe a few others and their meanings.


ΓòÉΓòÉΓòÉ 4.3.6. Next Month ΓòÉΓòÉΓòÉ

Next month, we will look at the tree view as well as look at a few other
notifications.  Also, we will build our first sample application using the
concepts described here and in next month's article.


ΓòÉΓòÉΓòÉ <hidden> Example Container Object Record ΓòÉΓòÉΓòÉ

Used as the object record type throughout this article, the definition is
below:

typedef struct _MYCNRREC {
   MINIRECORDCORE mrcCore;
   CHAR achText[256];
   ULONG ulNumSold;
   float fGrossIncome;
   float fNetIncome;
   float fTotalCost;
   float fNetProfit;
} MYCNRREC, *PMYCNRREC;


ΓòÉΓòÉΓòÉ 5. Columns ΓòÉΓòÉΓòÉ

o Questions and Answers

o Introduction to PM


ΓòÉΓòÉΓòÉ 5.1. Questions and Answers ΓòÉΓòÉΓòÉ

Welcome to this month's "Questions and Answers"!  Each month, I collect various
questions sent to me via email and try to answer each directly; the ones that I
feel contribute the most to developers, whether in terms of information or as a
nifty trick to tuck into your cap, get published in this column.

To submit a question, send mail to my email address - [e-mail] - and be
sure to grant permission to publish your question (those that forget will not
be considered for publication).

This month's deluge of questions covered the following topics:

o Using Presentation Parameters
o Context-specific Dialogs
o Adjusting the Priority of a Non-related Process
o Hooking the Kernel APIs
o Using MMPM/2 to Record and Playback Audio Samples


ΓòÉΓòÉΓòÉ 5.1.1. Using Presentation Parameters ΓòÉΓòÉΓòÉ

Les Chan ([e-mail]) writes:

How do I create buttons (and other standard classes) with custom fonts? I think
the way to do this is with the last parameter in WinCreateWindow, which is
PVOID pPresParams.  But I can't figure out how to use it.

Also, once the window is created, one should be able to change the font with
WinSetPresParams.  And I can't get this to work consistently (the window is
created with pPresParams=NULL).

So, what is the correct way to create and manipulate presentation parameters?

To answer your second question first, the most common problem with using
WinSetPresParam is not passing the correct values for the parameters; this
often manifests itself when attempting to change the font of a control.  What
most developers do not know, when using a string for the value of the
presentation parameter, is that you must add one to the length for the `\0'
byte at the end.

WinSetPresParam(hwndButton,
                PP_FONTNAMESIZE,
                strlen("12.Helv"),
                "12.Helv");

WinSetPresParam(hwndButton,
                PP_FONTNAMESIZE,
                strlen("12.Helv")+1,
                "12.Helv");

Thus, the first example is incorrect and will yield indeterminable results,
while the second will work as expected.  Using WinSetPresParam will work
regardless of the value of pPresParam on the WinCreateWindow call.

Your first question is a bit more complex, due to the fact that the online and
hardcopy documentation for 1.x and 2.0 are incorrect.  Piecing together the
information from all sources reaps the solution, however.  In the
WinCreateWindow call, the last parameter is defined to be of type PVOID when in
reality it is of type PPRESPARAMS.  This type is a variable length structure
which contains one or more presentation parameters to be passed to the window
(I won't review the structure definition, since you can do that on your own).
By initializing this structure properly, you can set the appropriate
characteristics on the call to WinCreateWindow as in the example below:

ULONG ulSzFont;
BYTE abBuf[sizeof(PRESPARAMS)+256];
PPRESPARAMS pppParm;

ulSzFont=strlen("18.Helv")+1;

pppParm=(PPRESPARAMS)abBuf;
pppParm->cb=sizeof(PARAM)+ulSzFont-1;
pppParm->aparam[0].id=PP_FONTNAMESIZE;
pppParm->aparam[0].cb=ulSzFont;
strcpy(pppParm->aparam[0].ab,"18.Helv");

if (WinCreateWindow(hwndWnd,
                    WC_BUTTON,
                    "Test",
                    WS_VISIBLE|BS_PUSHBUTTON,
                    100,
                    100,
                    200,
                    100,
                    hwndWnd,
                    HWND_TOP,
                    1,
                    NULL,
                    pppParm)==NULLHANDLE) {
   WinAlarm(HWND_DESKTOP,WA_ERROR);
   return MRFROMSHORT(FALSE);
} /* endif */

An interesting note here is that, when testing this, this code did not result
in an error, yet no button was displayed when I placed this in the WM_CREATE
processing.


ΓòÉΓòÉΓòÉ 5.1.2. Context-specific Dialogs ΓòÉΓòÉΓòÉ

A user who wishes to remain anonymous writes:

I'm writing a program that is essentially a dialog.  I know how to do that.
But I want to have a portion be dependant on another part, but don't know how
to make that happen.  For example, when you click on an radio button in the top
half, the bottom half changes so you can change settings for it.

If you have any experience using the notebook, you can design your main dialog
in a related fashion.  For each radio button in the top half, call WinLoadDlg
to load an auxilliary dialog specific to the item that radio button represents.
Then, when you receive the WM_CONTROL/ BN_CLICKED notification message, call
WinShowWindow both to hide the currently displayed dialog and to display the
dialog corresponding to the button selected.

As a caveat, define the auxilliary dialogs as having no border and not having
any frame controls (FCF_ flags).  You will also need to call WinSetWindowPos
after loading them to set their position to be the lower half of the main
dialog.


ΓòÉΓòÉΓòÉ 5.1.3. Adjusting the Priority of a Non-related Process ΓòÉΓòÉΓòÉ

Roman Stangl (86505339awiwuw11.wu-wien.ac.at) writes:

How can the priority of any running process be adjusted, without these
processes being child processes of the program that wants to adjust the
priority.

The answer is that you can't, at least as far as I am aware.  If you have the
source to the child processes, you can modify them to accept a command line
parameter specifying the desired priority class and value and then have them
call DosSetPriority.


ΓòÉΓòÉΓòÉ 5.1.4. Hooking the Kernel APIs ΓòÉΓòÉΓòÉ

Roman Stangl (86505339awiwuw11.wu-wien.ac.at) again writes:

How can the OS/2 API DosOpen() be hooked to trace write accesses to files,
similar to a DOS TSR that hooks into INT21?

The only way I know of to accomplish what your second question is asking is by
writing your own IFS (installable file system).  You might be able to also do
this using device monitors, but I cannot be sure. My apologies for the lack of
a concrete answer to this.


ΓòÉΓòÉΓòÉ 5.1.5. Using MMPM/2 to Record and Playback Audio Samples ΓòÉΓòÉΓòÉ

Marc Van-Woerkom ([e-mail]) writes:

I own a Soundblaster card and want to use it under OS/2!

It's FM synthesizers generate some nice sounds but I think the best effects are
produced by it's digital channel. For this I need a driver/routines that allow
me to record and play a sample.

A solution already exists (sbos2 package) but that's only an intermediate
solution -- with OS/2 2.1 MMPM/2 will become the standard to deal with.

So is there a MMPM/2 API which allows me to record/play samples?

In the Summer 1992 issue of the OS/2 Developer magazine, there is an article
entitled "Listen to the Sounds: The MMPM/2 Audio Subsystem" starting on page
98.  In this article, the author discusses how both audio samples and MIDI
sequences are used in the MMPM/2 system.  Since I personally have no experience
using MMPM/2, I will not try to explain the article in order to avoid confusing
anyone, but will consider the reference as an affirmative answer to your
question.

Now that the magazine is published by Miller Freeman, I am unsure if back
issues can be ordered.  If so, the IBM Mechanicsburg number is G362-0001; if
not, you can try contacting the magazine via the Internet at the address
[e-mail] for the possibility of article reprints.


ΓòÉΓòÉΓòÉ 5.2. Introduction to PM Programming - Part III ΓòÉΓòÉΓòÉ

                    Introduction to PM Programming - Part III

                                   Gavin Baker
                          ([e-mail])


ΓòÉΓòÉΓòÉ 5.2.1. Introduction ΓòÉΓòÉΓòÉ

  Introduction

Menus, dialog boxes and icons are all examples of Resources in OS/2.  Resources
are stored in their own read-only segment within the executable file (or DLL),
can be shared between multiple instances of a program, and are normally loaded
only when required at runtime rather than at the load time of the application.

The most commonly used resource types along with their definition are shown
below:

ΓöîΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö¼ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÉ
ΓöéType                ΓöéDescription                   Γöé
Γö£ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöñ
ΓöéACCELTABLE          ΓöéKeyboard Accelerator table    Γöé
Γö£ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöñ
ΓöéBITMAP              ΓöéBitmap                        Γöé
Γö£ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöñ
ΓöéDIALOG              ΓöéDialog box template           Γöé
Γö£ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöñ
ΓöéFONT                ΓöéFont                          Γöé
Γö£ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöñ
ΓöéMENU                ΓöéMenu definition               Γöé
Γö£ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöñ
ΓöéMESSAGETABLE        ΓöéApplication Message Strings   Γöé
Γö£ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöñ
ΓöéPOINTER             ΓöéIcon or mouse pointer         Γöé
Γö£ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöñ
ΓöéRCDATA*             ΓöéCustom-defined resource       Γöé
Γö£ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöñ
ΓöéSTRINGTABLE         ΓöéStrings                       Γöé
ΓööΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö┤ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÿ

Resources are created in two ways (depending on the type of resource).  They
are either text or binary. The binary resources are POINTER, BITMAP, and FONT.
All the other resources are textual. The RCDATA type is special, as it allows
the programmer to define a custom structure for a resource.

The RC.EXE program is called the Resource Compiler, and it takes the your
source file and compiles it into a binary form (.RES).  It also binds the .RES
file with your executable.

We will examine the general syntax of resources and the structure of the RC
file, and then examine each type in detail.


ΓòÉΓòÉΓòÉ 5.2.2. Scope ΓòÉΓòÉΓòÉ

  Scope

I am assuming that you are a competent C programmer, and have a working
knowledge of OS/2 from a user's perspective. The sample code here was produced
with Borland's Resource Workshop for PM and tested with the OS/2 Resource
Compiler (RC).


ΓòÉΓòÉΓòÉ 5.2.3. Syntax and the RC File ΓòÉΓòÉΓòÉ

  Syntax and the RC File

Resources are defined in a text file with the .RC extension. There are a number
of keywords for the different resource types, and each keyword defines one
resource.  Resources are referenced by an identifier, which takes the form of a
C #define.  Since the Resource Compiler (RC.EXE) supports C-like #includes and
#defines, it is convenient to have all the symbols defined in one header file
for the resources and their IDs. (Obviously they must have unique numbers).
Resources are usually named according a certain convention - ID followed by a
single letter denoting the resource type, an underscore and then a descriptive
name.  Here are some examples:

#define  IDM_FILE    10         /* the ID of the FILE Menu      */
#define  IDS_ERROR   300        /* the ID of the ERROR String   */
#define  IDD_OPTIONS 436        /* the ID of the OPTIONS Dialog */

Generally speaking, a resource statement consists of the following:

TYPE ΓöÇΓöÇΓöÇΓöÇ IDENTIFIER ΓöÇΓö¼ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö¼ΓöÇ RESOURCE DEFINITION ΓöÇΓöÇΓöÇΓöÇΓöñ
                       Γöé           Γöé
                       Γöé  MEMORY   Γöé
                       ΓööΓöÇ OPTIONS ΓöÇΓöÿ

Due to the differing nature of resources, it is easier to show the syntax for
each type's definition rather than to generalize here.

The options refer to the Memory Options, which specify how OS/2 treats the
memory occupied by the resource.  The memory options are as follows:

ΓöîΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö¼ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÉ
ΓöéOption              ΓöéMeaning                                                     Γöé
Γö£ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöñ
ΓöéFIXED or            ΓöéResource remains at a fixed point in memory                 Γöé
ΓöéMOVEABLE*           ΓöéResource can be moved by the system in memory               Γöé
Γö£ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöñ
ΓöéPRELOAD or          ΓöéResource is loaded at load-time                             Γöé
ΓöéLOADONCALL*         ΓöéResource is loaded when first referenced (run-time)         Γöé
Γö£ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöñ
ΓöéDISCARDABLE         ΓöéResource can be discarded if not needed                     Γöé
ΓööΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö┤ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÿ

Note that the default options are marked with an asterisk.  These options apply
to all of the resource types.


ΓòÉΓòÉΓòÉ 5.2.4. Resources ΓòÉΓòÉΓòÉ

  Resources

In the following sections we will see each type of resource (at least the most
common ones) and some examples, along with how to use them in your programs.

The syntax diagrams follow those conventions used in the Command Reference, but
also note that keywords are underlined.


ΓòÉΓòÉΓòÉ 5.2.4.1. String Table ΓòÉΓòÉΓòÉ

  String Table

  Syntax

STRINGTABLE ΓöÇΓöÇΓöÇΓöÇ IDENTIFIER ΓöÇΓö¼ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö¼ΓöÇ BEGIN ΓöÇΓöÇΓöÇΓöÇ
                              Γöé           Γöé
                              Γöé  MEMORY   Γöé
                              ΓööΓöÇ OPTIONS ΓöÇΓöÿ

         ΓöîΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÉ
         Γöé                             Γöé
                                      Γöé
   ΓöÇ ΓöÇ ΓöÇΓöÇΓöÇΓöÇ IDENTIFIER ΓöÇΓöÇΓöÇΓöÇ STRING ΓöÇΓöÇΓö┤ΓöÇΓöÇ


ΓöÇ ΓöÇ ΓöÇΓöÇΓöÇΓöÇ END ΓöÇΓöÇΓöÇΓöÇΓöñ

  Notes

String tables are used to keep all of the static text which is used in a
program in one place, thus making it easier to manage, and also to maintain
versions in multiple languages.  Ideally the program source code should be free
of static or literal text, and instead use a STRINGTABLE to manage the text.
Strings are loaded by using the WinLoadString call, and once loaded, are used
exactly the same way as a normal string.

 Example

STRINGTABLE ID_ERRORS FIXED
BEGIN
    IDS_FILENOTFOUND       "Sorry - I can't find that file anywhere!"
    IDS_NOGAMES            "Games are not allowed during office hours."
    IDS_BYEBYE             "Are you sure you really truly want to go?"
END

  Output

There is no output as such from this resource - you would use it in your
program like this:

WinLoadString(hab, NULLHANDLE, IDS_BADCMD, MAXERRORLEN, pszError);
WinMessageBox(HWND_DESKTOP,HWND_DESKTOP,pszError,"Error!",0,
              MB_CUACRITICAL | MB_OK);

This will load an error message from the executable file and display an error
message in a box.


ΓòÉΓòÉΓòÉ 5.2.4.2. Message Table ΓòÉΓòÉΓòÉ

  Message Table

  Syntax

MESSAGETABLE ΓöÇΓöÇΓöÇΓöÇ IDENTIFIER ΓöÇΓö¼ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö¼ΓöÇ BEGIN ΓöÇΓöÇΓöÇΓöÇ
                               Γöé           Γöé
                               Γöé  MEMORY   Γöé
                               ΓööΓöÇ OPTIONS ΓöÇΓöÿ

         ΓöîΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÉ
         Γöé                             Γöé
                                      Γöé
   ΓöÇ ΓöÇ ΓöÇΓöÇΓöÇΓöÇ IDENTIFIER ΓöÇΓöÇΓöÇΓöÇ STRING ΓöÇΓöÇΓö┤ΓöÇΓöÇ


ΓöÇ ΓöÇ ΓöÇΓöÇΓöÇΓöÇ END ΓöÇΓöÇΓöÇΓöÇΓöñ

  Notes

A Message table works just the same way as a STRINGTABLE. Most applications use
a STRINGTABLE, or use the MKMSGF (the Make MeSsaGe File utility, documented in
the Toolkit Tools Reference).

 Example

MESSAGETABLE ID_ERRORS
BEGIN
    IDM_PRINTEDOK     "The file has been successfully printed."
    IDM_SYNTAX        "A syntax error was found on line %1."
END


ΓòÉΓòÉΓòÉ 5.2.4.3. Menu ΓòÉΓòÉΓòÉ

  Menu

  Syntax

MENU ΓöÇΓöÇΓöÇΓöÇ IDENTIFIER ΓöÇΓö¼ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö¼ΓöÇ BEGIN ΓöÇΓöÇΓöÇΓöÇ
                       Γöé           Γöé
                       Γöé  MEMORY   Γöé
                       ΓööΓöÇ OPTIONS ΓöÇΓöÿ

      ΓöîΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÉ
      Γöé                                                                                 Γöé
                                                                                       Γöé
   ΓöÇ ΓöÇ ΓöÇΓöÇΓöÇΓöÇ SUBMENU ΓöÇΓöÇΓöÇΓöÇ TEXT ΓöÇΓöÇΓöÇΓöÇ IDENTIFIER ΓöÇΓöÇΓöÇΓöÇ STYLE ΓöÇΓöÇΓöÇΓöÇ BEGIN ΓöÇΓöÇΓöÇΓöÇ          Γöé
                                                                                        Γöé
         ΓöîΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÉ   Γöé
         Γöé                                                                          Γöé   Γöé
                                                                                   Γöé   Γöé
      ΓöÇ ΓöÇ ΓöÇΓöÇΓöÇΓöÇ MENUITEM ΓöÇΓöÇΓöÇΓöÇ TEXT ΓöÇΓöÇΓöÇΓöÇ IDENTIFIER ΓöÇΓöÇΓöÇΓöÇ STYLE ΓöÇΓöÇΓöÇΓöÇ ATTRIBUTES ΓöÇΓöÇΓö┤ΓöÇ Γöé
                                                                                        Γöé
                                                                                        Γöé
   ΓöÇ ΓöÇ ΓöÇΓöÇΓöÇΓöÇ END ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö┤ΓöÇΓöÇΓöÇ


ΓöÇ ΓöÇ ΓöÇΓöÇΓöÇΓöÇ END ΓöÇΓöÇΓöÇΓöÇΓöñ

  Notes

I hope this diagram isn't too confusing - if you examine it, all it means is
that a MENU consists of one or more SUBMENUs, which consist of one or more
MENUITEMs.  You can leave off the style and attributes if you don't want to
specify any (see the example).  Put a tilde ~ character in to specify that the
following letter will be the underlined shortcut key.

Note:  If you make the ID of the menu the same as your main window that you
       create with WinCreateStdWindow and use the FCF_MENU style when you
       create it, PM will automatically load the menu and assign it to the
       window.

 Example

MENU ID_MAIN
BEGIN
    SUBMENU "~File", IDM_FILE
    BEGIN
        MENUITEM "~New",       IDM_FILENEW
        MENUITEM "~Open...",   IDM_FILEOPEN
        MENUITEM "~Save",      IDM_FILESAVE
        MENUITEM "Save ~As...",IDM_FILESAVEAS
    END
    SUBMENU "Fon~t", IDM_FONT
    BEGIN
        MENUITEM "~Small",     IDM_FONTSMALL
        MENUITEM "~Medium",    IDM_FONTMED,    MIS_TEXT, MIA_CHECKED
        MENUITEM "~Large",     IDM_FONTLARGE
        MENUITEM SEPARATOR
        MENUITEM "~Options...",IDM_FONTOPTIONS
    END
END

  Output


ΓòÉΓòÉΓòÉ 5.2.4.4. Dialog ΓòÉΓòÉΓòÉ

  Dialog

  Syntax  The dialog template itself:

DLGTEMPLATE ΓöÇΓöÇΓöÇΓöÇ IDENTIFIER ΓöÇΓö¼ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö¼ΓöÇ BEGIN ΓöÇΓöÇΓöÇΓöÇ
                              Γöé           Γöé
                              Γöé  MEMORY   Γöé
                              ΓööΓöÇ OPTIONS ΓöÇΓöÿ

   ΓöÇ ΓöÇ ΓöÇΓöÇΓöÇΓöÇ DIALOG ΓöÇΓöÇΓöÇΓöÇ TITLE, ID, X, Y, WIDTH, HEIGHT ΓöÇΓö¼ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö¼ΓöÇ BEGIN ΓöÇΓöÇΓöÇΓöÇ
                                                          Γöé          Γöé
                                                          ΓööΓöÇ STYLES ΓöÇΓöÿ

            ΓöîΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÉ
            Γöé                       Γöé
                                   Γöé
      ΓöÇ ΓöÇ ΓöÇΓöÇΓöÇΓöÇ CONTROL DEFINITION ΓöÇΓö┤ΓöÇΓöÇ


   ΓöÇ ΓöÇ ΓöÇΓöÇΓöÇΓöÇ END ΓöÇΓöÇΓöÇΓöÇ


ΓöÇ ΓöÇ ΓöÇΓöÇΓöÇΓöÇ END ΓöÇΓöÇΓöÇΓöÇΓöñ

The Control Definition:

CONTROL ΓöÇΓöÇΓöÇΓöÇ TEXT, ΓöÇΓöÇΓöÇΓöÇ ID, ΓöÇΓöÇΓöÇΓöÇ X, ΓöÇΓöÇΓöÇΓöÇ Y, ΓöÇΓöÇΓöÇΓöÇ


ΓöÇ ΓöÇ ΓöÇΓöÇΓöÇΓöÇ WIDTH, ΓöÇΓöÇΓöÇΓöÇ HEIGHT, ΓöÇΓö¼ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö¼ΓöÇΓöñ
                                Γöé          Γöé
                                ΓööΓöÇ STYLES ΓöÇΓöÿ

  Notes

A dialog template is used to define a dialog, which contains many controls. The
control can be a custom control, or one of the following:

Γûá  AUTOCHECKBOX

Γûá  AUTORADIOBUTTON

Γûá  CHECKBOX

Γûá  DEFPUSHBUTTON

Γûá  GROUPBOX

Γûá  PUSHBUTTON

Γûá  RADIOBUTTON

Γûá  ENTRYFIELD

to name a few.  Consult the Toolkit documentation for a complete description of
all the different controls.  Once you know how to use one, the others work
basically the same.

 Example

This example was produced with Borland's Resource Workshop for PM (part of
Borland C++ for OS/2), which makes it easy to visually design dialogs and other
resources. The IBM Toolkit also includes a Dialog Editor.

As you can see, a reasonably simple dialog can get fairly complex.  If you were
to write this by hand it would take hours to figure out the X and Y positions,
flags, etc.  This is not practical for anything but the simplest of dialogs, so
a dialog editor (such as the two mentioned above) is invaluable.

This may seem complicated, but it is fairly straightforward.  Everything except
the buttons is defined as a CONTROL (a generic way of specifying a control).
The type of control is given in the flags, for example the comment edit field
is defined as a WC_ENTRYFIELD, and has its own specific flags (ES_LEFT and the
others).  There are lots of flags specified (more than if you had done it by
hand) but most have reasonable defaults.

Three things to note:

Γûá  The order is important - it is the order the user tabs through in.

Γûá  The WS_TABSTOP flag must be specified if you want the user to be able to tab
to the control under keyboard control.

Γûá  Groups (WS_GROUP) are mainly used to group together automatic radio buttons,
so they turn each other off and on.

DLGTEMPLATE 1
BEGIN
  DIALOG "Sample Dialog", 100, 30, 90, 300, 150, WS_VISIBLE, FCF_SYSMENU | FCF_TITLEBAR
  BEGIN
    CONTROL "", 109, 44, 104, 72, 35, WC_COMBOBOX, CBS_DROPDOWN | ES_ANY | WS_VISIBLE | WS_GROUP | WS_TABSTOP
    CONTROL "", 112, 156, 128, 133, 9, WC_ENTRYFIELD, ES_LEFT | ES_AUTOSCROLL | ES_MARGIN | ES_ANY | WS_VISIBLE | WS_GROUP | WS_TABSTOP
    CONTROL "~Preload", 102, 20, 96, 50, 10, WC_BUTTON, BS_AUTORADIOBUTTON | WS_VISIBLE | WS_GROUP | WS_TABSTOP
    CONTROL "~Load on Call", 103, 20, 80, 72, 10, WC_BUTTON, BS_AUTORADIOBUTTON | WS_VISIBLE | WS_TABSTOP
    CONTROL "~Fixed", 104, 104, 96, 50, 10, WC_BUTTON, BS_AUTORADIOBUTTON | WS_VISIBLE | WS_GROUP | WS_TABSTOP
    CONTROL "~Moveable", 105, 104, 80, 50, 10, WC_BUTTON, BS_AUTORADIOBUTTON | WS_VISIBLE | WS_TABSTOP
    CONTROL "~Discardable", 106, 20, 56, 68, 10, WC_BUTTON, BS_AUTOCHECKBOX | WS_VISIBLE | WS_GROUP | WS_TABSTOP
    CONTROL "", 107, 172, 84, 48, 12, WC_SPINBUTTON, SPBS_MASTER | SPBS_ALLCHARACTERS | SPBS_JUSTLEFT | WS_VISIBLE | WS_GROUP | WS_TABSTOP
    CONTROL "", 108, 236, 84, 48, 12, WC_SPINBUTTON, SPBS_MASTER | SPBS_ALLCHARACTERS | SPBS_JUSTLEFT | WS_VISIBLE | WS_GROUP | WS_TABSTOP
    CONTROL "", 113, 172, 56, 48, 12, WC_SPINBUTTON, SPBS_MASTER | SPBS_ALLCHARACTERS | SPBS_JUSTLEFT | WS_VISIBLE | WS_GROUP | WS_TABSTOP
    CONTROL "", 114, 236, 56, 48, 12, WC_SPINBUTTON, SPBS_MASTER | SPBS_ALLCHARACTERS | SPBS_JUSTLEFT | WS_VISIBLE | WS_GROUP | WS_TABSTOP
    CONTROL "", 121, 16, 26, 268, 12, WC_ENTRYFIELD, ES_LEFT | ES_AUTOSCROLL | ES_MARGIN | ES_ANY | WS_VISIBLE | WS_GROUP | WS_TABSTOP
    CONTROL "~Memory Options", 101, 10, 48, 150, 72, WC_STATIC, SS_GROUPBOX | DT_LEFT | DT_TOP | DT_MNEMONIC | WS_VISIBLE | WS_GROUP
    CONTROL "T~ype", 110, 8, 128, 27, 8, WC_STATIC, SS_TEXT | DT_LEFT | DT_TOP | DT_MNEMONIC | WS_VISIBLE | WS_GROUP
    CONTROL "~Text", 111, 130, 128, 24, 8, WC_STATIC, SS_TEXT | DT_LEFT | DT_TOP | DT_MNEMONIC | WS_VISIBLE | WS_GROUP
    CONTROL "X", 115, 172, 96, 32, 8, WC_STATIC, SS_TEXT | DT_LEFT | DT_TOP | DT_MNEMONIC | WS_VISIBLE
    CONTROL "Size & Position", 116, 163, 48, 129, 72, WC_STATIC, SS_GROUPBOX | DT_LEFT | DT_TOP | DT_MNEMONIC | WS_VISIBLE | WS_GROUP
    CONTROL "Y", 117, 238, 96, 32, 8, WC_STATIC, SS_TEXT | DT_LEFT | DT_TOP | DT_MNEMONIC | WS_VISIBLE
    CONTROL "Width", 118, 172, 72, 45, 8, WC_STATIC, SS_TEXT | DT_LEFT | DT_TOP | DT_MNEMONIC | WS_VISIBLE
    CONTROL "Height", 119, 236, 72, 45, 8, WC_STATIC, SS_TEXT | DT_LEFT | DT_TOP | DT_MNEMONIC | WS_VISIBLE
    CONTROL "Comment", 120, 10, 20, 282, 28, WC_STATIC, SS_GROUPBOX | DT_LEFT | DT_TOP | DT_MNEMONIC | WS_VISIBLE | WS_GROUP
    DEFPUSHBUTTON "OK", DID_OK, 6, 4, 51, 14
    PUSHBUTTON "Cancel", DID_CANCEL, 60, 4, 51, 14
    PUSHBUTTON "Help", 998, 114, 4, 51, 14, BS_HELP
  END
END

  Output


ΓòÉΓòÉΓòÉ 5.2.4.5. Fonts, Icons, Pointers, and Bitmaps ΓòÉΓòÉΓòÉ

  Fonts, Icons, Pointers, and Bitmaps

  Syntax

ΓöÇΓö¼ΓöÇ FONT    ΓöÇΓö¼ΓöÇ IDENTIFIER ΓöÇΓö¼ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö¼ΓöÇ FILENAME ΓöÇΓöÇΓöÇΓöÇΓöñ
 Γöé  BITMAP   Γöé               Γöé  MEMORY   Γöé
 ΓööΓöÇ POINTER ΓöÇΓöÿ               ΓööΓöÇ OPTIONS ΓöÇΓöÿ

  Notes

Fonts, icons, pointers and bitmaps are all treated in the same way. (In fact
icons and pointers are more or less identical). They are all defined externally
in their own binary file, and are bound in when the resources are compiled.

There are editors available to design your own binary resources. An Icon Editor
(also used for pointers and small bitmaps) is included in base OS/2, and there
is a Font Editor in the Toolkit.

 Example

BITMAP IDB_SMILEY  Smiley.Bmp
ICON   IDI_MYPROG  Whiz.Ico
FONT   IDF_BIGFONT Large.Fnt

  Output

<Insert your favourite graphic here>


ΓòÉΓòÉΓòÉ 5.2.5. Roundup ΓòÉΓòÉΓòÉ

  Roundup

Well, there you have Resources in a nutshell.  You will find that tools such as
Borland's Resource Workshop and those included with IBM's Toolkit can save you
from ever having to understand all that we have just discussed, as you can
point and click and the work is done for you.

However, it is very useful to know just how resources are created as it gives
you a better understanding of just what you are doing.

Now for those of you who have eagerly gone to consult your manuals (or the
header files for that matter), you will have noticed that I left out a few
resource types.  I did this to save both time and space, and also because they
are infrequently used.  I won't dare say that it is left as an excercise for
the reader, but if there is enough demand I will cover the remaining types in a
later article.


ΓòÉΓòÉΓòÉ 5.2.6. What Next? ΓòÉΓòÉΓòÉ

  What Next?

Next we look at the Graphics Programming Interface (GPI).

I would love to hear from you about what you thought, how useful it was,
whether or not there was too much or not enough information, if it was too
wordy or too simple - in short any and all comments are most welcome. Also, if
there is something specific you would like to see covered, drop me a line too.


ΓòÉΓòÉΓòÉ 5.2.7. Bibliography ΓòÉΓòÉΓòÉ

  Bibliography

The following references were used in the preparation of this article:

Γûá  OS/2 Version 2.0 - The Redbooks

Γûá  OS/2 Version 2.0 Technical Library

The following products were mentioned:

Γûá  IBM OS/2 Toolkit Version 2.0

Γûá  Borland C++ for OS/2 Version 1.0


ΓòÉΓòÉΓòÉ 6. Future Attractions ΓòÉΓòÉΓòÉ

Coming up in the future, we have:

o Introduction to PM Part 4

o Writing Installable File Systems

o Getting Started with IPF

o And much more!


ΓòÉΓòÉΓòÉ 7. Contributors to this issue ΓòÉΓòÉΓòÉ

o Andre Asselin

o Gavin R Baker

o Steve Luzynski

o Charles Oldham

o Larry Salomon


ΓòÉΓòÉΓòÉ 7.1. Andre Asselin ΓòÉΓòÉΓòÉ

Andre Asselin recently graduated Cum Laude from Rensselaer Polytechnic
Institute with a Bachelor of Science degree in Computer Science.  He has worked
with OS/2 since version 1.3, including several beta copies of version 2.0, and
also has extensive experience with MS-DOS and Microsoft Windows.  He has
co-oped twice in IBM's TCP/IP Development Department in Raleigh NC, where his
responsibilities included the NFS client and server components of TCP/IP for
OS/2.  In August, he will be rejoining the group full time.

Andre is also a member of Alpha Sigma Phi Fraternity, and enjoys hockey, the
beach, and a good science fiction novel.  He can be reached via email at
[e-mail] or on CompuServe at 73765,673.


ΓòÉΓòÉΓòÉ 7.2. Gavin R Baker ΓòÉΓòÉΓòÉ

  Gavin R Baker

Gavin R Baker is the man behind  ThinkSoft, a consulting firm based in
Melbourne Australia which specialises in developing custom software. He is an
active member of Team OS/2, and is the Editor for the Victorian Independent
OS/2 Developer's Group (VioDevGrp). When he isn't programming, he is also a
musician, an actor, and wastes lots of time reading Net News. He can be
contacted thusly:

net: [e-mail]
cis: 100026,270


ΓòÉΓòÉΓòÉ 7.3. Steve Luzynski ΓòÉΓòÉΓòÉ

Steve Luzynski is the editor and creator of this magazine. He is currently a
Computer Engineering student at University of Missouri at Columbia, after
leaving Case Western Reserve University in Cleveland, OH, where it was just too
cold. Steve has released several small programs for IBM's TCP/IP using Pat
Mueller's rxSock library for REXX. He is currently working on the ultimate file
manager, designed in conjuction with several hard-core DOS file manager users.
It should see release as soon as Steve figures out how exactly to do all of
this cool C++ 'object' stuff in OS/2 PM. Did you know you can't export a member
function of a class? <sigh>

Steve can by reached via e-mail at:

Internet  - [e-mail]
       [e-mail]
       [e-mail]
       [e-mail]
Delphi   - sluzynski
Compuserve - 72677,2140
FidoNet   - Steve Luzynski @ 1:280/304 (Multitasking Systems, K.C., MO)

The old fashioned kind of mail can currently find Steve home for the summer at:

Steve Luzynski
3604 S. 10th ST CT
Blue Springs, MO 64015-6238


ΓòÉΓòÉΓòÉ 7.4. Charles Oldham ΓòÉΓòÉΓòÉ

Charles R. (C. R.) Oldham resides in Mesa, Arizona with his wife Amy.  He is
currently working as the systems analyst for the North Central Association, a
non-profit organization that accredits schools in the 20 state region roughly
in the central United States.  C. R. is an experienced Dos, Macintosh, and Unix
programmer who is eagerly moving into the area of OS/2 applications development
and is trying to take as many people with him as he can.

C. R. can be reached via Internet email or snail mail at the following
addresses:

Internet Email:  [e-mail]

U. S. Mail:      C. R. Oldham
                 North Central Association
                 Arizona State University
                 Tempe, AZ  85287-3011


ΓòÉΓòÉΓòÉ 7.5. Larry Salomon ΓòÉΓòÉΓòÉ

Larry Salomon wrote his first Presentation Manager application for OS/2 version
1.1 in 1989.  Since that time, he has written numerous VIO and PM applications,
including the Scramble applet included with OS/2 and the I-Brow/Magnify/Screen
Capture trio included with the IBM Professional Developers Kit CD-ROM currently
being distributed by IBM.  Currently, he works for International Masters
Publishers in Stamford, Connecticut and resides in Bellerose, New York with his
wife Lisa.


ΓòÉΓòÉΓòÉ <hidden>  ΓòÉΓòÉΓòÉ

EMX/GCC can be retrieved from the official OS/2 anonymous FTP site, ftp-os2.
nmsu.edu, in the directory /pub/os2/2.x/unix/gnu/emx-0.8f.  An installation
guide for the system can be found in the first issue of EDM/2.


ΓòÉΓòÉΓòÉ <hidden>  ΓòÉΓòÉΓòÉ

DevHlps - A set of calls available to IFSs and device drivers to perform common
functions, such as allocating memory.


ΓòÉΓòÉΓòÉ <hidden>  ΓòÉΓòÉΓòÉ

Doscalls - Any of the DosXxx calls available in OS/2, such as DosOpen, DosRead,
etc.


ΓòÉΓòÉΓòÉ <hidden>  ΓòÉΓòÉΓòÉ

FSD (File System Driver) - A system extension that allows OS/2 to access files
stored in different disk formats or across a network.  Also called an IFS.


ΓòÉΓòÉΓòÉ <hidden>  ΓòÉΓòÉΓòÉ

FSH (File System Helpers) - A set of calls available to IFSs that perform
common functions, such as allocating memory and managing semaphores.


ΓòÉΓòÉΓòÉ <hidden>  ΓòÉΓòÉΓòÉ

GDT (Global Descriptor Table) - The table of selectors that are valid across
all processes.


ΓòÉΓòÉΓòÉ <hidden>  ΓòÉΓòÉΓòÉ

IFS (Installable File System) - A system extension that allows OS/2 to access
files stored in different disk formats or across a network.  Also called an
FSD.


ΓòÉΓòÉΓòÉ <hidden>  ΓòÉΓòÉΓòÉ

IPE (Internal Processing Error) - An unrecoverable system halt caused by buggy
ring 0 code.


ΓòÉΓòÉΓòÉ <hidden>  ΓòÉΓòÉΓòÉ

LDT (Local Descriptor Table) - The table of selectors that is allocated on a
per process basis.  Every process has its own LDT.  A particular LDT selector
is valid only in its own process.


ΓòÉΓòÉΓòÉ <hidden>  ΓòÉΓòÉΓòÉ

NFS (Network File System) - A protocol developed by Sun Microsystems to allow
UNIX machines to share files across a network.


ΓòÉΓòÉΓòÉ <hidden>  ΓòÉΓòÉΓòÉ

UNC (Universal Naming Convention) - The '\\server\path\file' naming convention,
where 'server' refers to the server the file is on.


ΓòÉΓòÉΓòÉ <hidden>  ΓòÉΓòÉΓòÉ

VMS - DEC's proprietary operating system for its VAX series of computers. One
of the nice features it supports is version levels for files (sort of an
automatic backup).