Checking the Major/Minor Return Code

If your program processes display, ICF, or printer files as stream files, you can check the external variable _C_Maj_Min_rc, which is defined in <stdio.h>. The following figure shows the definition of this structure.

typedef struct _Major_Minor_rc
{
    char major_rc[2];
    char minor_rc[2];
}  _Major_Minor_rc;
extern _Major_Minor_rc _C_Maj_Min_rc;