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  4.15  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)