gsignal, ssignal - software signal facility
Contents
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 │
└─────────────────────────────────────────────────────────────────────┴───────────────┴─────────────────┘
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).
History
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().
Library
Standard C library (libc, -lc)
Name
gsignal, ssignal - software signal facility
See Also
kill(2), signal(2), raise(3) Linux man-pages 6.9.1 2024-05-02 gsignal(3)
Standards
None.
Synopsis
#include<signal.h>typedefvoid(*sighandler_t)(int);[[deprecated]]intgsignal(intsignum);[[deprecated]]sighandler_tssignal(intsignum,sighandler_taction); 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
