1COAP_LOGGING(3)                 libcoap Manual                 COAP_LOGGING(3)
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NAME

6       coap_logging, coap_log, coap_get_log_level, coap_set_log_level,
7       coap_set_log_handler, coap_package_name, coap_package_version,
8       coap_set_show_pdu_output, coap_show_pdu - Work with CoAP logging
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SYNOPSIS

11       #include <coap2/coap.h>
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13       void coap_log(coap_log_t level, const char *format, ...);
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15       void coap_set_log_level(coap_log_t level);
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17       coap_log_t coap_get_log_level(void);
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19       void coap_dtls_set_log_level(int level);
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21       int coap_dtls_get_log_level(void);
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23       void coap_set_log_handler(coap_log_handler_t handler);
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25       const char *coap_package_name(void);
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27       const char *coap_package_version(void);
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29       void coap_set_show_pdu_output(int use_fprintf);
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31       void coap_show_pdu(coap_log_t level, const coap_pdu_t *pdu);
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33       const char *coap_endpoint_str(const coap_endpoint_t *endpoint);
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35       const char *coap_session_str(const coap_session_t *session);
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37       Link with -lcoap-2, -lcoap-2-gnutls, -lcoap-2-openssl or
38       -lcoap-2-tinydtls depending on your (D)TLS library type.
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DESCRIPTION

41       The logging sub-system supports logging at different levels, and
42       depending on the selected logging level, outputs the appropriate
43       information.
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45       Logging by default is to stderr or stdout depending on the logging
46       level of the log entry. It ia possible to send the logging information
47       to an application logging call-back handler for processing by the
48       application.
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50       The coap_log() function is used to log information at the appropriate
51       level. The rest of the parameters follow the standard printf() function
52       format.
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54       Logging levels (coap_log_t) are defined by (the same as for syslog()),
55       which are numerically incrementing in value:
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57       LOG_EMERG
58           Emergency level (0).
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60       LOG_ALERT
61           Alert level (1).
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63       LOG_CRIT
64           Critical level (2).
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66       LOG_ERR
67           Error level (3).
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69       LOG_WARNING
70           Warning level (the default) (4).
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72       LOG_NOTICE
73           Notice level (5).
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75       LOG_INFO
76           Information level (6).
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78       LOG_DEBUG
79           Debug level (7).
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81       The coap_set_log_level() function is used to set the current logging
82       level for output by any subsequent coap_log() calls. Output is only
83       logged if the coap_log() level definition is smaller than or equal to
84       the curent logging level.
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86       The coap_get_log_level() function is used to get the current logging
87       level.
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89       The coap_dtls_set_log_level() function is used to set the logging level
90       for output by the DTLS library for specific DTLS information. Usually,
91       both coap_set_log_level() and coap_dtls_set_log_level() would be set to
92       the same level value. If the logging level is set to greater than
93       LOG_DEBUG, the underlying TLS library may get more verbose in its
94       output.
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96       The coap_dtls_get_log_level() function is used to get the current
97       logging level for the DTLS library.
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99       The coap_set_log_handler()* function can be used to define an
100       alternative logging handler for processing the logging messages. The
101       logging handler prototype is defined as:
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103           typedef void (*coap_log_handler_t) (coap_log_t level, const char *message);
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105       The coap_package_name() function returns the name of this library.
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107       The coap_package_version() function returns the version of this
108       library.
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110       The coap_set_show_pdu_output() function defines whether the output from
111       coap_show_pdu() is to be either sent to stdout/stderr, or output using
112       coap_log(). use_fprintf is set to 1 for stdout/stderr (the default),
113       and use_fprintf is set to 0 for coap_log().
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115       The coap_show_pdu() function is used to decode the pdu, outputting as
116       appropriate for logging level. Where the output goes is dependent on
117       coap_set_show_pdu_output().
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119       The coap_endpoint_str() function returns a description string of the
120       endpoint.
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122       The coap_session_str() function is used to get a string containing the
123       information about the session.
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RETURN VALUES

126       The coap_package_name() and coap_package_version() return the
127       appropriate zero-terminated character string.
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129       The coap_get_log_level() function returns the current logging level.
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131       The coap_dtls_get_log_level() function returns the current logging
132       level for the DTLS library specifics.
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134       The coap_endpoint_str() function returns a description string of the
135       endpoint.
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137       The coap_session_str() function returns a description string of the
138       session.
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SEE ALSO

141       coap_context(3) and coap_session(3)
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FURTHER INFORMATION

144       See "RFC7252: The Constrained Application Protocol (CoAP)" for further
145       information.
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BUGS

148       Please report bugs on the mailing list for libcoap:
149       libcoap-developers@lists.sourceforge.net
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AUTHORS

152       The libcoap project <libcoap-developers@lists.sourceforge.net>
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156coap_logging 4.2.1                07/28/2020                   COAP_LOGGING(3)
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