sigaction(3)

NAME

sigaction − software signal facilities (POSIX)

SYNTAX

#include <signal.h>

struct sigaction {
void (*sa_handler)();
sigset_t sa_mask;
int sa_flags;
};

int sigaction(sig, vec, ovec)
int sig;
struct sigaction *vec, *ovec;

DESCRIPTION

The siagaction call is the POSIX equivalent to the sigvec() system call. This call behaves as described on the sigvec() reference page with the following modifications:

•The signal mask is manipulated using the sigsetops() functions.

•A process can supress the generation of the SIGCHLD when a child stops by setting the SA_NOCLDSTOP bit in sa_flags.

•The SV_INTERRUPT flag is always set by the system when using sigaction() in POSIX mode.

RETURN VALUE

A 0 return value indicated that the call succeeded. A −1 return value indicates an error occurred and errno is set to indicated the reason.

DIAGNOSTICS

The sigaction system call fails and a new signal handler is not installed if one of the following occurs:

[EFAULT] Either vec or ovec points to memory which is not a valid part of the process address space.

[EINVAL] Sig is not a valid signal number.

[EINVAL] An attempt is made to ignore or supply a handler for SIGKILL or SIGSTOP.

[EINVAL] An attempt is made to ignore SIGCONT (by default SIGCONT is ignored).

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