SIGPROCMASK(2) 1990 SIGPROCMASK(2) NNAAMMEE sigprocmask - manipulate current signal mask SSYYNNOOPPSSIISS ##iinncclluuddee <<ssiiggnnaall..hh>> ssiiggpprrooccmmaasskk((hhooww,, sseett,, oosseett));; iinntt hhooww;; ssiiggsseett__tt **sseett,, **oosseett;; mmaasskk == ssiiggmmaasskk((ssiiggnnuumm)) DDEESSCCRRIIPPTTIIOONN The _s_i_g_s_e_t_m_a_s_k function examines and/or the current signal mask (those signals that are blocked from delivery). Sig- nals are blocked if they are members of the current signal mask set. If _s_e_t is not null, the action of _s_i_g_s_e_t_m_a_s_k depends on the value of the parameter _h_o_w. The signal mask is changed as a function of the specified _s_e_t and the current mask. The function is specified by _h_o_w using one of the following values from <signal.h>: SIG_BLOCK The new mask is the union of the current mask and the specified _s_e_t. SIG_UNBLOCK The new mask is the intersection of the current mask and the complement of the specified _s_e_t. SIG_SETMASK The current mask is replaced by the specified _s_e_t. If _o_s_e_t is not null, the previous value of the signal mask. When _s_e_t is null, this provides a way to examine the signal mask without changing it. The system quietly disallows SIGKILL or SIGSTOP to be blocked. RREETTUURRNN VVAALLUUEE A 0 value indicated that the call succeeded. A -1 return value indicates an error occurred and _e_r_r_n_o is set to indi- cated the reason. EERRRROORRSS The _s_i_g_p_r_o_c_m_a_s_k call will fail and the signal mask will be unchanged if one of the following occurs: [EINVAL] _h_o_w has a value other than those listed here. Printed 7/27/90 July 1 SIGPROCMASK(2) 1990 SIGPROCMASK(2) SSEEEE AALLSSOO kill(2), sigaction(2), sigsetops(2), sigsuspend(2) Printed 7/27/90 July 2