The
bsd_signal()
function takes the same arguments, and performs the same task, as
signal(2).
The difference between the two is that
bsd_signal()
is guaranteed to provide reliable signal semantics, that is:
a) the disposition of the signal is not reset to the default
when the handler is invoked;
b) delivery of further instances of the signal is blocked while
the signal handler is executing; and
c) if the handler interrupts a blocking system call,
then the system call is automatically restarted.
A portable application cannot rely on
signal(2)
to provide these guarantees.
RETURN VALUE
The
bsd_signal()
function returns the previous value of the signal handler, or
SIG_ERR
on error.
4.2BSD, POSIX.1-2001.
POSIX.1-2008 removes the specification of
bsd_signal(),
recommending the use of
sigaction(2)
instead.
NOTES
Use of
bsd_signal()
should be avoided; use
sigaction(2)
instead.
On modern Linux systems,
bsd_signal()
and
signal(2)
are equivalent.
But on older systems,
signal(2)
provided unreliable signal semantics; see
signal(2)
for details.
The use of
sighandler_t
is a GNU extension;
this type is only defined if the
_GNU_SOURCE
feature test macro is defined.
This page is part of release 3.27 of the Linux
man-pages
project.
A description of the project,
and information about reporting bugs,
can be found at
http://www.kernel.org/doc/man-pages/.