
Notes for MsDOS (mawk 1.1)
---------------

command.com doesn't understand ' so if you use command.com as your
shell (the norm under DOS) then on the command line (and NOT from
files) the meanings of " and ' are reversed.

	mawk "{ print 'hello world' }"

If this seems too weird, use

	mawk -f con
	{ print "hello world" }
	^Z

If you use a DOS shell that gives you a Unix style command line, to use 
it you'll need to provide a C function reargv() that retrieves argc and 
argv[] from your shell.

To enable system and pipes you need to tell mawk about your shell by
setting the environment variable MAWKSHELL.  E.g, with command.com

      set MAWKSHELL=c:\sys\command.com /c

or with a unix like shell

      set MAWKSHELL=c:\bin\sh.exe -c

in your autoexec.bat.  The full path with drive and extension and
appropriate switch is required.  (Small model is a tight squeeze
and there's not enought room for PATH searching code.)

If you want to use a ram disk for the pipes, set MAWKTMPDIR.

      set MAWKTMPDIR=d:\

The trailing backslash is required.  You have to set MAWKSHELL,
MAWKTMPDIR is optional -- defaulting to the current directory.

For compatibility with Unix, CR are silently stripped from input and LF 
silently become CRLF on output.  Also ^Z indicates EOF on input (
evidently for compatibility with CPM!!!).

CR control can be turned off, with a new variable BINMODE.
BINMODE defaults to 0.

     BINMODE = 1 gives binary input.
     BINMODE = 2 gives binary output.
     BINMODE = 3 gives both.

Setting BINMODE with -v or in the BEGIN section affects all
files, otherwise it only affects files opened after the 
assignment to BINMODE.  Once a file is open, later assignment to
BINMODE does not affect it.  Note that with binary output, printf
will behave strangely -- you'll need to explicitly use \r

  Eg    mawk -v BINMODE=2 '{ printf "%d %s\r\n", NR, $0}'

Assignment to BINMODE does not change RS or ORS; however there is
a -W feature 

   -W BINMODE=1   is the same as
   -v BINMODE=1 -v RS="\r\n" or BEGIN{BINMODE=1 ; RS = "\r\n" }

   -W BINMODE=2   is the same as
   -v BINMODE=2 -v ORS="\r\n" or BEGIN{BINMODE=2 ; ORS = "\r\n" }

   -W BINMODE=3  is the same as
   -v BINMODE=3 -v RS=ORS="\r\n" or BEGIN{BINMODE=2 ; RS=ORS = "\r\n" }


Setting MAWKBINMODE in the environment is the same as using -W,
except its permanent.
If you rarely have to deal with text files that contain ^Z,
then setting MAWKBINMODE=1 in the environment would speed up input
slightly.


----------------------------------------------------------
WARNING: If you write an infinite loop that does not print to the 
screen, then you will have to reboot.  For example 

	x = 1 
	while( x < 10 )  A[x] = x
	x++

By mistake the x++ is outside the loop.  What you need to do is type 
control break and the keyboard hardware will generate an interrupt and 
the operating system will service that interrupt and terminate your 
program, but unfortunately MsDOS does not have such a feature.  


how to make mawk under MsDOS
---------------------------

   Rename Makefile Makefile.unx
   Move or copy msdos\dosexec.c to source directory

TurboC: Move msdos\Makefile.tcc to Makefile
	copy msdos\tcc_dos.h to config.h

MSC:    Move msdos\Makefile.MSC to Makefile

Assuming you keep the same directory structure:

1)  If you want a Unix style command line for mawk, you'll need to
    write a function called reargv(int *, char ***) which passes
    mawk the modified argc and argv via reargv(&argc,&argv).
    Put it in a file called reargv.c

    The supplied reargv.c works with POLYSHELL by Polytron; for a
    different shell you could use it as an example.
    (I've looked at the MKS documentation and writing reargv() for
     MKS ksh would be easy.  (contributions welcome)).

2)  TurboC look at comments in Makefile.  Remember to remove
    .obj between make of bmawk.exe and mawk.exe.


3) Using MSC , move Makefile.MSC to mawk directory and
   run nmake -- makes both small and large model


4)  YACC --
Take some care that you don't trash parse.[ch] unless you're
sure you want to remake them.
(If using a make, also check that the date of parse.c is
newer than parse.y or parse2.xc)
If you don't change parse.y, the parse.c and parse.h provided
were made with Berkeley yacc and can be redistributed and you
don't need a yacc.  The executables look bigger than before,
but I reuse the parser table memory which returns 15K to the
mem pool.

5)  The same test suite that is run on mawk under Unix can now
be run under DOS.  The same anonymous reviewer wrote  batch
files mawktest.bat and fpe_test.bat.



POSSIBLE PROBLEMS:

1) Using TurboC++ 1.0, the code segment is 153 bytes short of
64K.  With another compiler or a different version of TurboC++,
this might not fit in 64K. If this is a problem,
then compile with -DNO_BINMODE which removes the BINMODE features
from small model only and then it should fit.

2)  MSC 5.1 requires /Os and /Gs for small model to fit in 64K.
Reports indicate this is also true with 6.0.

