signal(3)signal(3)NAMEsignal - Modifies signal functions
SYNOPSIS
#include <signal.h>
void (*signal(
int sig,
void (*function)(int)) (int) );
LIBRARY
SVR4 Library (libsvr4)
PARAMETERS
Defines the signal. All signals are valid with the exception of
SIGKILL and SIGSTOP. Specifies the address of a signal handler.
DESCRIPTION
The signal() function provides compatibility for older versions of the
operating system whose function is a subset of the sigaction() func‐
tion. The signal() function sets the action associated with a signal.
The function parameter uses the values SIG_DFL, SIG_IGN, or it can
point to an address of a signal handler.
A SIG_DFL value specifies the default action that is to be taken when
the signal is delivered. A value of SIG_IGN specifies that the signal
has no effect on the receiving process. A pointer to a function
requests that the signal be caught; that is, the signal should cause
the function to be called. These actions are more fully described in
the <signal.h> file.
NOTES
[Tru64 UNIX] The specified signal is not blocked from delivery when
the handler is entered, and the disposition of the signal reverts to
SIG_DFL when the signal is delivered.
RETURN VALUES
Upon successful completion of the signal() function, the value of the
previous signal action is returned. Otherwise, SIG_ERR is returned and
errno is set to indicate the error.
ERRORS
The signal() function sets errno to the specified values for the fol‐
lowing conditions: The sig parameter is not a valid signal number or an
attempt was made to catch a signal that cannot be caught or to ignore a
signal that cannot be ignored.
RELATED INFORMATION
Commands: kill(1)
Functions: acct(2), bsd_signal(2), exit(2), kill(2), ptrace(2), sigac‐
tion(2), sigblock(2), sigprocmask(2), sigstack(2), sigsuspend(2),
sigvec(2), umask(2), wait(2), pause(3), setjmp(3), sigpause(3)
Files: signal(4)signal(3)
