1GSIGNAL(3) Linux Programmer's Manual GSIGNAL(3)
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6 gsignal, ssignal - software signal facility
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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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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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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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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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62 kill(2), signal(2), raise(3)
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65 This page is part of release 5.10 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 2020-04-11 GSIGNAL(3)