gsignal(3) — Linux manual page

NAME | LIBRARY | SYNOPSIS | DESCRIPTION | ATTRIBUTES | STANDARDS | HISTORY | SEE ALSO

gsignal(3)              Library Functions Manual              gsignal(3)

NAME         top

       gsignal, ssignal - software signal facility

LIBRARY         top

       Standard C library (libc, -lc)

SYNOPSIS         top

       #include <signal.h>

       typedef void (*sighandler_t)(int);

       [[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

DESCRIPTION         top

       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         top

       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 │
       └─────────────────────────────┴───────────────┴─────────────────┘

STANDARDS         top

       None.

HISTORY         top

       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         top

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

Linux man-pages (unreleased)     (date)                       gsignal(3)