GSIGNAL(3)						     Linux Programmer's Manual							GSIGNAL(3)

NAME

       gsignal, ssignal - software signal facility

SYNOPSIS

       #include <signal.h>

       typedef void (*sighandler_t)(int);

       int gsignal(int signum);

       sighandler_t ssignal(int signum, sighandler_t action);

   Feature Test Macro Requirements for glibc (see feature_test_macros(7)):

       gsignal(), ssignal():
	   Since glibc 2.19:
	       _DEFAULT_SOURCE
	   Glibc 2.19 and earlier:
	       _SVID_SOURCE

DESCRIPTION

       Don't  use  these  functions under Linux.  Due to a historical mistake, under Linux these functions are aliases for raise(3) and signal(2),
       respectively.

       Elsewhere, on System V-like systems, these functions implement software signaling, entirely independent	of  the  classical  signal(2)  and
       kill(2) functions.  The function ssignal() defines the action to take when the software signal with number signum is raised using the func-
       tion gsignal(), and returns the previous such action or SIG_DFL.  The function gsignal() does the following: if no action  (or  the  action
       SIG_DFL)  was specified for signum, then it does nothing and returns 0.	If the action SIG_IGN was specified for signum, then it does noth-
       ing and returns 1.  Otherwise, it resets the action to SIG_DFL and calls the action function with argument signum, and  returns	the  value
       returned by that function.  The range of possible values signum varies (often 1-15 or 1-17).

ATTRIBUTES

       For an explanation of the terms used in this section, see attributes(7).

       +----------+---------------+-----------------+
       |Interface | Attribute	  | Value	    |
       +----------+---------------+-----------------+
       |gsignal() | Thread safety | MT-Safe	    |
       +----------+---------------+-----------------+
       |ssignal() | Thread safety | MT-Safe sigintr |
       +----------+---------------+-----------------+

CONFORMING TO

       These  functions are available under AIX, DG/UX, HP-UX, SCO, Solaris, Tru64.  They are called obsolete under most of these systems, and are
       broken under Linux libc and glibc.  Some systems also have gsignal_r() and ssignal_r().

SEE ALSO

       kill(2), signal(2), raise(3)

COLOPHON

       This page is part of release 4.15 of the Linux man-pages project.  A description of the project, information about reporting bugs, and  the
       latest version of this page, can be found at https://www.kernel.org/doc/man-pages/.

								    2017-09-15								GSIGNAL(3)