gsignal(3) - Linux manual page (original) (raw)

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 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

DESCRIPTION top

   Don't use these functions under Linux.  Due to a historical
   mistake, under Linux these functions are aliases for [raise(3)](../man3/raise.3.html) and
   [signal(2)](../man2/signal.2.html), respectively.

   Elsewhere, on System V-like systems, these functions implement
   software signaling, entirely independent of the classical
   [signal(2)](../man2/signal.2.html) and [kill(2)](../man2/kill.2.html) 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)](../man7/attributes.7.html).
   ┌──────────────────────────────┬───────────────┬─────────────────┐
   │ **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)](../man2/kill.2.html), [signal(2)](../man2/signal.2.html), [raise(3)](../man3/raise.3.html)

COLOPHON top

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Linux man-pages 6.10 2024-12-13 gsignal(3)