Manual Pages for UNIX Operating System command usage for man sem

Headers                                              sem.h(3HEAD)



NAME
     sem.h, sem -  semaphore facility

SYNOPSIS
     #include 


DESCRIPTION
     The  header defines the following  constants  and
     structures.


     Semaphore operation flags:

     SEM_UNDO    Set up adjust on exit entry.



     Command definitions for the semctl() function  are  provided
     as listed below. See semctl(2).

     GETNCNT    Get semncnt.


     GETPID     Get sempid.


     GETVAL     Get semval.


     GETALL     Get all cases of semval.


     GETZCNT    Get semzcnt.


     SETVAL     Set semval.


     SETALL     Set all cases of semval.



     The semid_ds structure contains the following members:

       struct ipc_perm sem_perm     /* operation permission structure */
       unsigned short  sem_nsems    /* number of semaphores in set */
       time_t          sem_otime    /* last semop() time */
       time_t          sem_ctime    /* last time changed by semctl() */






SunOS 5.11          Last change: 10 Sep 2004                    1






Headers                                              sem.h(3HEAD)



     The pid_t, time_t, key_t, and size_t types  are  defined  as
     described in . See types.h(3HEAD).


     A semaphore is represented by an  anonymous  structure  con-
     taining the following members:

       unsigned short semval     /* semaphore value */
       pid_t          sempid     /* process ID of last operation */
       unsigned short semncnt    /* number of processes waiting for semval
                                    to become greater than current value */
       unsigned short semzcnt    /* number of processes waiting for semval
                                    to become 0 */



     The sembuf structure contains the following members:

       unsigned short sem_num     /* semaphore number */
       short          sem_op      /* semaphore operation */
       short          sem_flg     /* operation flags */



     All of the symbols from  are  defined  when  this
     header is included. See ipc.h(3HEAD).

ATTRIBUTES
     See attributes(5) for descriptions of the  following  attri-
     butes:



     ____________________________________________________________
    |       ATTRIBUTE TYPE        |       ATTRIBUTE VALUE       |
    |_____________________________|_____________________________|
    | Interface Stability         | Committed                   |
    |_____________________________|_____________________________|
    | Standard                    | See standards(5).           |
    |_____________________________|_____________________________|


SEE ALSO
     semctl(2),      semget(2),      semop(2),      ipc.h(3HEAD),
     types.h(3HEAD), attributes(5), standards(5)










SunOS 5.11          Last change: 10 Sep 2004                    2