#pragma strings(readonly)
#include <stdlib.h>
#include <string.h>
#include <stdio.h>

typedef int EXTF();
#pragma linkage(EXTF,OS)

int main(int argc, char **argv) {
extern char **environ;                /* access environ variables     */
EXTF *irxjcl;                         /* pointer to IRXJCL routine    */
EXTF *bpxwrbld;                       /* pointer to BPXWRBLD routine  */
char *penvb;                          /* addr of REXX environment     */
int  i,j;                             /* temps                        */
long rcinit;                          /* return code                  */
int  **environlp;                     /* ptr to env length pointers   */
int  *environl;                       /* ptr to env lengths           */
char rxwork[16000];                   /* OE MVS env work area         */
char *execname="execname";            /* name of exec up to 8 chars   */
char *execparm="exec parameter string"; /* parm to exec               */
struct s_rxparm {                     /* parm to IRXJCL               */
   short len;                         /* halfword length of parm      */
   char name[8];                      /* area to hold exec name       */
   char space;                        /* one space                    */
   char text[253];                    /* big area for exec parm       */
   } *rxparm;

   /* if stdin or stdout are not open you might want to open file     */
   /* descriptors 0 and 1 here                                        */

   /* if no environ, probably tso or batch - make one                 */
   if (environ==NULL) {
      environ=(char **)malloc(8);          /* create one              */
      environ[0]="PATH=.";                 /* set PATH to cwd         */
      environ[1]=NULL;                     /* env terminator          */
      };

   /* need to build the environment in the same format as expected by */
   /* the exec() callable service.  See                               */
   /* Assembler Callable Services for UNIX System Services.                */

   /* the environ array must always end with a NULL element           */
   for (i=0;environ[i]!=NULL;i++);         /* count vars              */
   environlp=(int **)malloc(i*4+4);        /* get array for len ptrs  */
   environl=(int *)malloc(i*4+4);          /* get words for len vals  */
   for (j=0;j<i;j++) {
      environlp[j]=&environl[j];           /* point to len            */
      environl[j]=strlen(environ[j])+1;    /* set len word            */
      };
   environlp[j]=NULL;                      /* null entry at end       */
   environl[j]=0;

   /* load routines                                                   */
    irxjcl=(EXTF *)fetch("IRXJCL   ");
   bpxwrbld=(EXTF *)fetch("BPXWRBLD ");

   /* build the REXX environment                                      */
   rcinit=bpxwrbld(rxwork,
                  argc,argv,
                  i,environlp,environ,
               &penvb);
   if (rcinit!=0) {
      printf("environment create failed rc=%d\n",rcinit);
      return 255;
      };

   /* if you need to add subcommands or functions to the environment, */
   /* or create a new environment inheriting the current one, this is */
   /* the place to do it.  The user field in the environment is used  */
   /* by the z/OS UNIX REXX support and must be preserved.      */

   /* run exec                                                        */
   rxparm=(struct s_rxparm *)malloc(strlen(execname)+
                                    strlen(execparm)+
                                    sizeof(struct s_rxparm));
   memset(rxparm->name,' ',sizeof(rxparm->name));
   memcpy(rxparm->name,execname,strlen(execname));
   rxparm->space=' ';
   memcpy(rxparm->text,execparm,i=strlen(execparm));
   rxparm->len=sizeof(rxparm->name)+sizeof(rxparm->space)+i;
   return irxjcl(rxparm);
}