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 function 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 nothing 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  glibc.  Some systems also have gsignal_r() and
       ssignal_r().

SEE ALSO

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

COLOPHON

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       information   about   reporting   bugs,   and   the  latest  version  of  this  page,  can  be  found  at
       https://www.kernel.org/doc/man-pages/.

                                                   2020-04-11                                         GSIGNAL(3)