sigsend(2)                                                       sigsend(2)




 NAME    [Toc]    [Back]
      sigsend(), sigsendset() - send a signal to a process or a group of
      processes

 SYNOPSIS    [Toc]    [Back]
      #include <sys/signal.h>

      #include <sys/procset.h>

      int sigsend (idtype_t idtype, id_t id, int sig);

      int sigsendset (const procset_t *psp, int sig);

 DESCRIPTION    [Toc]    [Back]
      The sigsend() system call sends a signal to a process or a group of
      processes.  The process or group of processes to which the signal is
      to be sent is specified by id and idtype.  The signal to be sent is
      specified by sig and is either one from the list given in signal()
      (see signal(2)) or 0.

      If sig is equal to zero (the null signal), error checking is performed
      but no signal is actually sent.  This can be used to check the
      validity of id and idtype.

      The real or effective user ID of the sending process must match the
      real or effective user ID of the receiving process, unless the process
      has appropriate privileges, or sig is SIGCONT and the sending process
      has the same session ID as the receiving process.

      idtype and id work together as follows:

           +  If idtype is P_PID, sig will be sent to the process with a
              process ID equal to (pid_t)id.

           +  If idtype is P_PGID, sig will be sent to any process with a
              process group ID equal to (pid_t)id.

           +  If idtype is P_SID, sig will be sent to any process with a
              session ID equal to (pid_t)id.

           +  If idtype is P_UID, sig will be sent to any process with an
              effective user ID equal to (uid_t)id.

           +  If idtype is P_GID, sig will be sent to any process with an
              effective group ID equal to (gid_t)id.

           +  If idtype is P_ALL, sig will be sent to all processes and id
              will be ignored.

           +  If id is P_MYID, the value of id is taken from the calling
              process.



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 sigsend(2)                                                       sigsend(2)




      The process with a process ID of 0 is always excluded.  The process
      with a process ID of 1 is included only if idtype is equal to P_PID.

      sigsendset() provides an alternate interface for sending signals to a
      set of processes.

      psp is a pointer to a structure that includes the following members:

           idop       p_op;
           idtype_t   p_lidtype;
           id_t       p_lid;
           idtype_t   p_ridtype;
           id_t       p_rid;

      The structure defines a set of processes as the result of a set
      operation (difference, union, intersection, or exclusion) on two
      operands (idtype/id pairs).  The left (right) operand is specified by
      p_lid (p_rid) and p_lidtype (p_ridtype).  p_lid (p_rid) takes the
      values specified by id and p_lidtype (p_ridtype) takes the values
      specified by idtype in the sigsend() system call defined above.  p_op
      specifies the operand, and takes one of the following values:

           POP_DIFF       Set difference.  The resultant set consists of the
                          processes that are in the left operand and not in
                          the right operand.

           POP_AND        Set intersection.  The resultant set consists of
                          the processes that are in both the left and right
                          operands.

           POP_OR         Set union.  The resultant set consists of the
                          processes that are in either the left or right
                          operand or both.

           POP_XOR        Set exclusive OR.  The resultant set consists of
                          the processes that are in either the left or right
                          operand but not in both.

 RETURN VALUE    [Toc]    [Back]
      Upon successful completion, sigsend() returns a value of 0.
      Otherwise, it returns a value of -1 and sets errno to indicate the
      error.

 ERRORS    [Toc]    [Back]
      If sigsend() fails, it sets errno (see errno(2)) to one of the
      following values:

           [EINVAL]       sig is neither a valid signal number nor zero.

           [EINVAL]       idtype is not a valid value.




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 sigsend(2)                                                       sigsend(2)




           [EINVAL]       sig is SIGKILL, idtype is P_PID, and id is 1.

           [ESRCH]        No process can be found corresponding to that
                          specified by id and idtype.

           [EPERM]        The user ID of the sending process is not 0, and
                          its real or effective user ID does not match the
                          real or effective user ID of the receiving
                          process, and the calling process is not sending
                          SIGCONT to a process that shares the same session
                          ID.

 SEE ALSO    [Toc]    [Back]
      kill(2), signal(2).


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