1GSIGNAL(3)                 Linux Programmer's Manual                GSIGNAL(3)
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NAME

6       gsignal, ssignal - software signal facility
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SYNOPSIS

9       #include <signal.h>
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11       typedef void (*sighandler_t)(int);
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13       int gsignal(int signum);
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15       sighandler_t ssignal(int signum, sighandler_t action);
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17   Feature Test Macro Requirements for glibc (see feature_test_macros(7)):
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19       gsignal(), ssignal():
20           Since glibc 2.19:
21               _DEFAULT_SOURCE
22           Glibc 2.19 and earlier:
23               _SVID_SOURCE
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DESCRIPTION

26       Don't  use  these  functions under Linux.  Due to a historical mistake,
27       under Linux these functions are aliases for raise(3) and signal(2), re‐
28       spectively.
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30       Elsewhere, on System V-like systems, these functions implement software
31       signaling, entirely independent of the classical signal(2) and  kill(2)
32       functions.   The function ssignal() defines the action to take when the
33       software signal with number signum is raised using the  function  gsig‐
34       nal(),  and  returns the previous such action or SIG_DFL.  The function
35       gsignal() does the following: if no action (or the action SIG_DFL)  was
36       specified  for  signum, then it does nothing and returns 0.  If the ac‐
37       tion SIG_IGN was specified for signum, then it does nothing and returns
38       1.   Otherwise,  it  resets  the action to SIG_DFL and calls the action
39       function with argument signum, and returns the value returned  by  that
40       function.   The  range  of possible values signum varies (often 1–15 or
41       1–17).
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ATTRIBUTES

44       For an  explanation  of  the  terms  used  in  this  section,  see  at‐
45       tributes(7).
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47       ┌────────────────────────────────────┬───────────────┬─────────────────┐
48       │Interface                           │ Attribute     │ Value           │
49       ├────────────────────────────────────┼───────────────┼─────────────────┤
50       │gsignal()                           │ Thread safety │ MT-Safe         │
51       ├────────────────────────────────────┼───────────────┼─────────────────┤
52       │ssignal()                           │ Thread safety │ MT-Safe sigintr │
53       └────────────────────────────────────┴───────────────┴─────────────────┘
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CONFORMING TO

56       These  functions  are  available under AIX, DG/UX, HP-UX, SCO, Solaris,
57       Tru64.  They are called obsolete under most of these systems,  and  are
58       broken  under  glibc.   Some  systems  also  have gsignal_r() and ssig‐
59       nal_r().
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SEE ALSO

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

65       This page is part of release 5.12 of the Linux  man-pages  project.   A
66       description  of  the project, information about reporting bugs, and the
67       latest    version    of    this    page,    can     be     found     at
68       https://www.kernel.org/doc/man-pages/.
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72                                  2021-03-22                        GSIGNAL(3)