sigaction(3)sigaction(3)NAMEsigaction - Specifies the action to take upon delivery of a signal
SYNOPSIS
#include <sys/signal.h>
int sigaction(
int sig,
const struct sigaction *sa,
struct sigaction *osa);
LIBRARY
SVR4 Library (libsvr4)
PARAMETERS
Defines the signal. Points to a sigaction structure that describes the
action to be taken upon receipt of the signal specified by the sig
parameter. Points to a sigaction structure. When the sigaction()
function returns from a call, the action previously attached to the
specified sig is stored in this structure.
DESCRIPTION
When a process requests the sigaction() function, the process can both
examine or specify what action is to be performed when the specified
signal is delivered. The parameters determine the behavior of the
sigaction() function as follows: Specifying the sig parameter identi‐
fies the signal that is to be affected. Specifying the sa parameter,
if not null, points to a sigaction structure that defines what action
is to be performed when the signal is received. If the sa parameter is
null, signal handling remains unchanged; thus the call can be used to
inquire about the current handling of the signal. Specifying the osa
parameter, if not null, points to a sigaction structure that contains
the action previously attached to the specified signal.
Once an action is installed for a specific signal, it remains installed
until one of the following events occurs: A sigaction() call that
explicitly requests a different action. A call to one of the exec*
functions.
The sig parameter can be any one of the signal values defined in the
signal.h header file, except SIGKILL and SIGSTOP.
NOTES
This version of sigaction exists only to call __Esigaction in libc.
This is required to ensure that System V signal handlers passed a ucon‐
text_t ptr instead of a struct sigcontext ptr.
RETURN VALUES
Upon successful completion of the sigaction() function, a value of zero
(0) is returned. If the sigaction() function fails, a value of -1 is
returned and errno is set to indicate the error.
ERRORS
If the sigaction() function fails, no new signal handler is installed
and errno may be set to one of the following values: The sa or osa
parameter points to a location outside of the allocated address space
of the process. The sig parameter is not a valid signal number.
RELATED INFORMATION
Commands: kill(1)
Functions: acct(2), exit(2), kill(2), ptrace(2), sigblock(2), sigproc‐
mask(2), sigstack(2), sigsuspend(2), sigvec(2), umask(2), wait(2),
pause(3), setjmp(3), sigpause(3)
Files: signal(4)
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sigaction(3)
