[Info-vax] Any Way to Pass Character String Arguments from C to Basic?

[Jonathan]

If you don't want to use descriptors in C, you can alias the argument types in BASIC.
b1 is safe, b2 and b3 open to error, but more useful/fast for some purposes.

JUC$ type/nopage c.c
#include <string.h>

void b1(char *s, short n);
void b2(char *s, short n);
void b3(char *s, short n);

int main(int argc,char *argv[])
{
     char *test = "Test";
     int testlen = strlen(test);

     b1(test,testlen);
     b2(test,testlen);
     b3(test,testlen);

     return 0;
}

JUC$ type/nopage b.bas
	function long b1( long a by value, word n by value )

	%include "$DSCDEF" %from %library "SYS$SHARE:BASIC$STARLET"

	external long function b1a( DSCDEF1 )

	declare DSCDEF1 dsc

	dsc::DSC$A_POINTER = a
	dsc::DSC$W_MAXSTRLEN = n
	dsc::DSC$B_DTYPE = DSC$K_DTYPE_T
	dsc::DSC$B_CLASS = DSC$K_CLASS_S

	end function b1a( dsc )


	function long b1a( string s )

	print "s=";s

	end function


	function long b2( string x = 32767 by ref, word n by value )

	external long function b1a( string )

	end function b1a( left$( x, n ) )



	function long b3( byte b(32766) by ref, word n by value )

	print "s=";
	for i = 0 to n - 1
	  print chr$(b(i));
	next i
	print

	end function
JUC$ cc c
JUC$ basic b
JUC$ link c+b
JUC$ run c
s=Test
s=Test
s=Test