Newbe trying to connect using Pro*C/C++

Question

I'm just trying to get Pro*C/C++ to work using VC++ on an NT platform (This is my first shot at Pro*C/C++).
I can get the code to pre-compile , compile, and link but when I attempt to connect to the database I get an Access Violation in SQLLIB80.dll .
Results with the lines below - Does the first sqlcxt parameter make any sense!?
EXPANDED CODE:
username.len = (unsigned short)strlen(strcpy((char *) username.arr, "testuser"));
password.len = (unsigned short)strlen(strcpy((char *)password.arr, "testpwd"));
dsname.len = (unsigned short)strlen(strcpy((char *)dsname.arr, "mercury"));
// Register sql_error() as the error handler
/* EXEC SQL WHENEVER SQLERROR DO sql_error("ORACLE error:"); */
/* EXEC SQL CONNECT :username IDENTIFIED BY :password USING :dsname; */
struct sqlexd sqlstm;
sqlstm.sqlvsn = 10;
sqlstm.arrsiz = 4;
sqlstm.sqladtp = &sqladt;
sqlstm.sqltdsp = &sqltds;
sqlstm.iters = (unsigned int )10;
sqlstm.offset = (unsigned int )5;
sqlstm.cud = sqlcud0;
sqlstm.sqlest = (unsigned char *)&sqlca;
sqlstm.sqlety = (unsigned short)256;
sqlstm.occurs = (unsigned int )0;
sqlstm.sqhstv[0] = ( void *)&username;
sqlstm.sqhstl[0] = (unsigned int )22;
sqlstm.sqhsts[0] = ( int )22;
sqlstm.sqindv[0] = ( void *)0;
sqlstm.sqinds[0] = ( int )0;
sqlstm.sqharm[0] = (unsigned int )0;
sqlstm.sqadto[0] = (unsigned short )0;
sqlstm.sqtdso[0] = (unsigned short )0;
sqlstm.sqhstv[1] = ( void *)&password;
sqlstm.sqhstl[1] = (unsigned int )42;
sqlstm.sqhsts[1] = ( int )42;
sqlstm.sqindv[1] = ( void *)0;
sqlstm.sqinds[1] = ( int )0;
sqlstm.sqharm[1] = (unsigned int )0;
sqlstm.sqadto[1] = (unsigned short )0;
sqlstm.sqtdso[1] = (unsigned short )0;
sqlstm.sqhstv[2] = ( void *)&dsname;
sqlstm.sqhstl[2] = (unsigned int )42;
sqlstm.sqhsts[2] = ( int )42;
sqlstm.sqindv[2] = ( void *)0;
sqlstm.sqinds[2] = ( int )0;
sqlstm.sqharm[2] = (unsigned int )0;
sqlstm.sqadto[2] = (unsigned short )0;
sqlstm.sqtdso[2] = (unsigned short )0;
sqlstm.sqphsv = sqlstm.sqhstv;
sqlstm.sqphsl = sqlstm.sqhstl;
sqlstm.sqphss = sqlstm.sqhsts;
sqlstm.sqpind = sqlstm.sqindv;
sqlstm.sqpins = sqlstm.sqinds;
sqlstm.sqparm = sqlstm.sqharm;
sqlstm.sqparc = sqlstm.sqharc;
sqlstm.sqpadto = sqlstm.sqadto;
sqlstm.sqptdso = sqlstm.sqtdso;
sqlcxt((void **)0, &sqlctx, &sqlstm, &sqlfpn);

Answer 1

Can't help you there, I'm afraid, and I don't do development since many years back so I'm pretty useless in that area ;-)
However, since the Net layers are beneath OCI in the stack, I would think that if these certificates work at all with Oracle (via some other client, like SQL*Plus), it should work with all types of apps.
But, I believe the Pro* stuff is not all that up to date, so if connectivity requires 10g features, there's a small risk of incompatibility issues.
http://download.oracle.com/docs/cd/B19306_01/server.102/b14225/ch7progrunicode.htm#i1005974
http://download.oracle.com/docs/cd/B19306_01/network.102/b14212/architecture.htm#i1040997