1MS_LOG(3) Library Functions Manual MS_LOG(3)
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6 ms_log - Central logging facility for libmseed
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10 #include <libmseed.h>
11 int ms_log (int level, const char *format, ...);
13 int ms_log_l (MSLogParam *logp, int level, const char *format, ...);
15 void ms_loginit (void (*log_print)(char*), const char *logprefix,
17 void (*diag_print)(char*), const char *errprefix);
18 MSLogParam * ms_loginit_l (MSLogParam *logp,
20 void (*log_print)(char*), const char *logprefix,
21 void (*diag_print)(char*), const char *errprefix);
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24 The ms_log functions are the central logging facility for all output
25 from libmseed functions. They are also intended to be used by libmseed
26 based programs if desired.
27 Three message levels are recognized:
29 0 : Normal log messgaes, printed using log_print with logprefix
30 1 : Diagnostic messages, printed using diag_print with logprefix
31 2+ : Error messages, printed using diag_print with errprefix
32 It is the task of the ms_log functions to format a message using printf
34 conventions and pass the formatted string to the appropriate printing
35 function (log_print or diag_print)
36 ms_log will process messages using the global logging parameters.
38 ms_log_l is a reentrant version of ms_log. It will use the logging
40 parameters specified in the supplied MSLogParam struct. If logp is
41 NULL global parameters will be used, this would be equivalent to a call
42 to ms_log(). This is intended for use only when complicated logging
43 schemes are desired, e.g. in a threaded application. Note that it is
44 not possible to set thread specific logging parameters for the internal
45 library functions because global parameters are used.
46 The ms_loginit functions are used to set the log and error printing
48 functions and the log and error message prefixes used by the ms_log
49 functions.
50 ms_loginit will operate on the global logging parameters.
52 ms_loginit_l is a reentrant version of ms_loginit. It will initialize
54 or change the logging parameters specified in the MSLogParam struct.
55 If logp is NULL a new MSLogParam struct will be allocated. A pointer
56 to the created or re-initialized MSLogParam struct will be returned.
57 The returned pointer is suitable for use with ms_log_l.
58 Use NULL for the print function pointers or the prefixes if they should
60 not be changed from previously set or default values.
61 The default values for the logging parameters are:
63 log_print = fprintf (printing to standard out)
64 log_prefix = ""
65 diag_print = fprintf (printing to standard error)
66 err_prefix = "error: "
67 By setting the printing functions it is possible to re-direct all of
69 the output from these logging routines. This is useful when the libm‐
70 seed based software is embedded in a system with it's own logging
71 facilities.
72 Most of the libmseed internal messages are logged at either the diag‐
74 nostic or error level.
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78 ms_log and ms_log_l return the number of characters formatted on suc‐
79 cess, and a negative value on error.
80 ms_loginit_l returns a pointer to the MSLogParam struct that it oper‐
82 ated on. If the input MSLogParam struct is NULL a new struct will be
83 allocated with malloc().
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87 Unless a complicated logging scheme is needed most uses of this logging
88 facility will be limited to the ms_loginit and ms_log functions.
89 An example of setting the printing functions:
91 #include <libmseed.h>
93 void log_print (const char *message);
95 void diag_print (const char *message);
96 main () {
98 ms_loginit (&log_print, "LOG: ", &diag_print, "ERR: ");
99 /* Normal log message, "LOG: " will be prefixed */
101 ms_log (0, "Normal log message for %s0, argv[0]);
102 /* Diognostic message, "LOG: " will be prefixed */
104 ms_log (1, "Diagnositc message for %s0, argv[0]);
105 /* Error message, "ERR: " will be prefixed */
107 ms_log (2, "Error message for %s0, argv[0]);
108 }
109 void log_print (const char *message) {
111 /* Send message to external log message facility */
112 send_log(message);
113 }
114 void diag_print (const char *message) {
116 /* Send message to external error message facility */
117 send_error(message);
118 }
119
122 Chad Trabant
123 IRIS Data Management Center
124 2014/07/16 MS_LOG(3)