| NAME | LIBRARY | SYNOPSIS | DESCRIPTION | ATTRIBUTES | STANDARDS | HISTORY | SEE ALSO | COLOPHON | |
|  | 
gsignal(3)               Library Functions Manual              gsignal(3)
       gsignal, ssignal - software signal facility
       Standard C library (libc, -lc)
       #include <signal.h>
       typedef typeof(void (int))  *sighandler_t;
       [[deprecated]] int gsignal(int signum);
       [[deprecated]] 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
       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).
       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 │
       └──────────────────────────────┴───────────────┴─────────────────┘
       None.
       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().
       kill(2), signal(2), raise(3)
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Linux man-pages 6.15            2025-05-17                     gsignal(3)