Re: API parameter lengths

[bmorris@xxxxxxxxxx]

>Date: Mon, 9 Jul 2001 10:54:23 -0500
>From: "Alexei Pytel" <pytel@us.ibm.com>
>
>CALL command does not do this.
>C PEP (program entry point) procedure does. For every main() in C,
compiler
>generates a PEP (you may see it if you do DSPMOD on C module). This PEP
>procedure among other things will scan for first blank in each parameter
>and create null-terminated string for each parameter.
?This makes it very difficult to pass non-character parameters to C main().

Alexei, that is not true; where did you hear that?  If you call a C program
with a parameter of 'abc def ghi', it will get one parameter.  The
null-termination is indeed done by the call command.

Calling a C program from another program is not difficult.  In that
case, the C program receives the same parameters that the caller passed
because the PEP doesn't do any processing on the parameters except to
build the argv array from the parameters that are passed to the program.
But it just copies the parameter pointers into the array of pointers; it
doesn't do anything with the parameter data.

A test:

#include <stdio.h>
main(int argc, char *argv[])
{
   int i;
   for (i = 1; i < argc; i++)
   {
      printf("arg %d %s\n", i, argv[i]);
   }
}
===> CALL pgm ('abc def ghi' 'zyx')
arg 1 abc def ghi
arg 2 zyx





Barbara Morris

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