The call to PSX_MALLOC allocates twenty bytes of storage. The subsequent call to PSX_REALLOC extends this area to forty bytes. The pointer to this storage is then passed to subroutine SUB1, where it is accessed as an array of INTEGERs. We assume SUB1 returns without action if STATUS is bad.
Note that in this case the program needs to know that an INTEGER variable is stored in four bytes. This is not portable. In such a case it is better to use the symbolic constants NUM_NB<T> defined in the file PRM_PAR to determine the number of bytes per unit of storage. (See SUN/39 for a description of these constants).
PSX POSIX interface routines