1sg_init(3)                                                          sg_init(3)
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NAME

6       sg_init, sg_snapshot, sg_shutdown, sg_drop_privileges - initialise lib‐
7       statgrab
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SYNOPSIS

10       #include <statgrab.h>
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13       void sg_log_init (const char *properties_pfx, const char *env_name,
14                        const char *argv0);
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16       sg_error sg_init (int ignore_init_errors);
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18       sg_error sg_snapshot (void);
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20       sg_error sg_shutdown (void);
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22       sg_error sg_drop_privileges (void);
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DESCRIPTION

25       sg_init() either initialises the statgrab library and sets the initial‐
26       isation counter to 1, if not already done, or increases the initialisa‐
27       tion  counter.   If  called for the first time (in fact: if called when
28       the initialisation counter is 0), the constructor (initialisation  rou‐
29       tine)  of  each  registered component is invoked, some global variables
30       are initialised, requested mutual exclusion semaphores are  initialised
31       and so on.  sg_init() is protected by the mutex named "statgrab".
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33       sg_log_init() allows some application-individual logging configuration.
34       It's intended for projects with several applications or commands  which
35       might  have  different appenders.  Mind that sg_log_init must be called
36       before sg_init, but after your application initialized  logging  frame‐
37       work.
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39       sg_snapshot() is Win32 only and will probably disappear.
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41       sg_shutdown()  decrements  the  initialisation  counter. If the counter
42       reaches zero, components' destructors are called, mutual exclusion sem‐
43       aphores  (exept  "statgrab")  are destroyed etc.  sg_shutdown() is pro‐
44       tected by the mutex named "statgrab".
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46       sg_drop_privileges() drops elevated privileges.
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RETURN VALUES

49       All functions return a statgrab error code. Either  SG_ERROR_NONE  when
50       everything was ok or the appropriate error code from an constructor/de‐
51       structor.
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EXAMPLE

54       Typical  initialization/deinitialization  sequence  when   using   with
55       log4cplus:
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57       static void *l4cplus_initializer;
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59       static void
60       cleanup_logging(void)
61       {
62              log4cplus_deinitialize(l4cplus_initializer);
63       }
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65       int
66       main(int argc, char const *argv[])
67       {
68           l4cplus_initializer = log4cplus_initialize();
69           atexit((void (*)(void))cleanup_logging);
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71           sg_log_init("saidar", "SAIDAR_LOG_PROPERTIES", argv[0]);
72           sg_init(1);
73           if(sg_drop_privileges() != 0) {
74            die("Failed to drop setuid/setgid privileges");
75           }
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77           do_something();
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79           sg_shutdown();
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81           return 0;
82       }
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84

SEE ALSO

86       statgrab(3)
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WEBSITE

89       ⟨https://libstatgrab.org/⟩
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93libstatgrab                       2019-03-24                        sg_init(3)
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