Content-type: text/html Man page of sigemptyset

sigemptyset

Section: C Library Functions (3)
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NAME

sigemptyset, sigfillset, sigaddset, sigdelset, sigismember - Creates and manipulates signal masks  

LIBRARY

Standard C Library (libc.so, libc.a)  

SYNOPSIS

#include <signal.h>

int sigemptyset (
        sigset_t *set);

int sigfillset (
        sigset_t *set);

int sigaddset (
        sigset_t *set,
        int sig_number );

int sigdelset (
        sigset_t *set,
        int sig_number );

int sigismember (
        sigset_t *set,
        int sig_number );  

STANDARDS

Interfaces documented on this reference page conform to industry standards as follows:

sigemptyset(), sigfillset(), sigaddset(), sigdelset() sigismember():  XPG4, XPG4-UNIX

Refer to the standards(5) reference page for more information about industry standards and associated tags.  

PARAMETERS

Specifies the signal set. Specifies the individual signal.  

DESCRIPTION

The sigemptyset(), sigfillset(), sigaddset(), sigdelset(), and sigismember() functions manipulate sets of signals. These functions operate on data objects that can be addressed by the application, not on any set of signals known to the system, such as the set blocked from delivery to a process or the set pending for a process.

The sigemptyset() function initializes the signal set pointed to by the set parameter such that all signals are excluded. The sigfillset() function initializes the signal set pointed to by the set parameter such that all signals are included. A call to either the sigfillset() or sigemptyset() function must be made at least once for each object of the type sigset_t prior to any other use of that object.

The sigaddset() and sigdelset() functions respectively add and delete the individual signal specified by the sig_number parameter from the signal set specified by the set parameter. The sigismember() function tests whether the sig_number parameter is a member of the signal set pointed to by the set parameter.  

EXAMPLES

To generate and use a signal mask that blocks only the SIGINT signal from delivery, enter: #include <signal.h> int return_value; sigset_t newset; . . .   sigemptyset(&newset); sigaddset(&newset, SIGINT); return_value = sigprocmask (SIG_SETMASK, &newset, NULL);  

RETURN VALUES

Upon successful completion, the sigismember() function returns a value of 1 if the specified signal is a member of the specified set, or a value of 0 (zero) if it is not. Upon successful completion, the other functions return a value of 0. For all the preceding functions, if an error is detected, a value of -1 is returned and errno is set to indicate the error.  

ERRORS

The sigfillset(), sigdelset(), sigismember(), and sigaddset() functions set errno to the specified values for the following conditions: The value of the sig_number parameter is not a valid signal number.  

RELATED INFORMATION

Functions: sigaction(2), sigprocmask(2), sigsuspend(2), sigvec(2)

Files: signal(4)

Standards: standards(5) delim off


 

Index

NAME
LIBRARY
SYNOPSIS
STANDARDS
PARAMETERS
DESCRIPTION
EXAMPLES
RETURN VALUES
ERRORS
RELATED INFORMATION

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Time: 02:42:18 GMT, October 02, 2010