Simon Ewins wrote in a message to All:

 SE> I have been experimenting with some .DLL stuff I've written
 SE> in C that is callable by REXX programs. I have got the
 SE> passing of simple variables back and forth working fine but
 SE> I can't seem to find any information anywhere on parsing a
 SE> stem. variable passed to C or passing a character array back
 SE> to REXX as a stem. variable.

 SE> Can anyone either tell me how this is accomplished (if it is
 SE> simple enough to explain here) or point me at the correct
 SE> book or datafile?

The OS/2 Toolkit has some REXX interface samples, including source code for
things like REXXUTIL.DLL.  (If you have the Watcom compiler, these are in
\watcom\samples\toolkt2x\rexx.)  The code for SysFileSearch() in REXXUTIL.C
contains pretty clear information about how to do this.


In REXXSAA.H:

/***    Structure for external interface string (RXSTRING) */

typedef struct _RXSTRING {          /* rxstr */
        ULONG  strlength;           /*   length of string         */
        PCH    strptr;              /*   pointer to string        */
}  RXSTRING;

typedef RXSTRING     *PRXSTRING;       /* pointer to a RXSTRING      */


/***    Structure of Shared Variable Request Block (SHVBLOCK) */

typedef struct _SHVBLOCK {            /* shvb */
    struct _SHVBLOCK  *shvnext;       /* pointer to the next block   */
    RXSTRING           shvname;       /* Pointer to the name buffer  */
    RXSTRING           shvvalue;      /* Pointer to the value buffer */
    ULONG              shvnamelen;    /* Length of the name value    */
    ULONG              shvvaluelen;   /* Length of the fetch value   */
    UCHAR              shvcode;       /* Function code for this block*/
    UCHAR              shvret;        /* Individual Return Code Flags*/
}   SHVBLOCK;

typedef SHVBLOCK *PSHVBLOCK;


In REXXUTIL.C:

/*********************************************************************/
/* RxStemData                                                        */
/*   Structure which describes as generic                            */
/*   stem variable.                                                  */
/*********************************************************************/

typedef struct RxStemData {
    SHVBLOCK shvb;                     /* Request block for RxVar    */
    CHAR ibuf[IBUF_LEN];               /* Input buffer               */
    CHAR varname[MAX];                 /* Buffer for the variable    */
                                       /* name                       */
    CHAR stemname[MAX];                /* Buffer for the variable    */
                                       /* name                       */
    ULONG stemlen;                     /* Length of stem.            */
    ULONG vlen;                        /* Length of variable value   */
    ULONG j;                           /* Temp counter               */
    ULONG tlong;                       /* Temp counter               */
    ULONG count;                       /* Number of elements         */
                                       /* processed                  */
} RXSTEMDATA;

 
-- Mike


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