getmajor(9F)

NAME

     getmajor - get major device number

SYNOPSIS

     #include <sys/types.h>
     #include <sys/mkdev.h>
     #include <sys/ddi.h>

     major_t getmajor(dev_t dev);

INTERFACE LEVEL

     Architecture independent level 1 (DDI/DKI).

PARAMETERS

     dev   Device number.

DESCRIPTION

     getmajor() extracts the major number from a device number.

RETURN VALUES

     The major number.

CONTEXT

     getmajor() can be called from user or interrupt context.

EXAMPLES

     Example 1: Using getmajor()

     The  following  example  shows  both  the   getmajor()   and
     getminor(9F)  functions  used in a debug  cmn_err(9F) state-
     ment to return the major and minor numbers  for  the  device
     supported by the driver.

          dev_t dev;

          #ifdef DEBUG
          cmn_err(CE_NOTE,"Driver Started.  Major# = %d,
               Minor# = %d", getmajor(dev), getminor(dev));
          #endif

SEE ALSO

     cmn_err(9F), getminor(9F), makedevice(9F)

     Writing Device Drivers

WARNINGS

     No validity checking is performed.  If  dev is  invalid,  an
     invalid number is returned.