Example

       /*      decc$write_eof_to_mbx_example.c         */

       #include <errno.h>
       #include <stdio.h>
       #include <string.h>

       #include <fcntl.h>
       #include <unistd.h>
       #include <unixio.h>

       #include <descrip.h>
       #include <ssdef.h>
       #include <starlet.h>

       int decc$write_eof_to_mbx( int );

       main()
       {
         int status, nbytes, failed = 0;
         int fd, fd2[2];
         short int channel;
         $DESCRIPTOR(mbxname_dsc, "TEST_MBX");
         char c;

         /* first try a mailbox created by SYS$CREMBX        */

       status = sys$crembx(0, &channel, 0, 0, 0, 0, &mbxname_dsc, 0, 0);
       if ( status != SS$_NORMAL ) {
            printf("sys$crembx failed: %s\n",strerror(EVMSERR, status));
            failed = 1;
         }

        if ( (fd = open(mbxname_dsc.dsc$a_pointer, O_RDWR, 0)) == -1) {
             perror("? open mailbox");
             failed = 1;
         }

         if ( decc$write_eof_to_mbx(fd) == -1 ) {
             perror("?  decc$write_eof_to_mbx to mailbox");
             failed = 1;
         }

         if ( (nbytes = read(fd, &c, 1)) != 0 || errno != 0 ) {
             perror("? read mailbox");
             printf("? nbytes = %d\n", nbytes);
             failed = 1;
         }

         if ( close(fd) == -1 ) {
             perror("? close mailbox");
             failed = 1;
         }

         /* Now do the same thing with a pipe                */

         errno = 0;           /* Clear errno for consistency */

         if ( pipe(fd2) == -1 ) {
             perror("? opening pipe");
             failed = 1;
         }

         if ( decc$write_eof_to_mbx(fd2[1]) == -1 ) {
             perror("? decc$write_eof_to_mbx to pipe");
             failed = 1;
         }

         if ( (nbytes = read(fd2[0], &c, 1)) != 0 || errno != 0 ) {
             perror("? read pipe");
             printf("? nbytes = %d\n", nbytes);
             failed = 1;
         }

         /* Close both file descriptors involved with the pipe    */

         if ( close(fd2[0]) == -1 ) {
             perror("close(fd2[0])");
             failed = 1;
         }

         if ( close(fd2[1]) == -1 ) {
             perror("close(fd2[1])");
             failed = 1;
         }

         if ( failed )
             puts("?Example program failed");
         else
             puts("Example ran to completion");
       }

     This example program produces the following result:

       Example ran to completion