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ssignal(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  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 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 4.09 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/.

                              2016-03-15                        GSIGNAL(3)



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