1SD_BUS_MESSAGE_GET_TYPE(3) sd_bus_message_get_type SD_BUS_MESSAGE_GET_TYPE(3)
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6 sd_bus_message_get_type, sd_bus_message_is_signal,
7 sd_bus_message_is_method_call, sd_bus_message_is_method_error - Query
8 bus message addressing metadata
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11 #include <systemd/sd-bus.h>
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13 int sd_bus_message_get_type(sd_bus_message *message, uint8_t *type);
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15 int sd_bus_message_is_signal(sd_bus_message *message,
16 const char *interface,
17 const char *member);
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19 int sd_bus_message_is_method_call(sd_bus_message *message,
20 const char *interface,
21 const char *member);
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23 int sd_bus_message_is_method_error(sd_bus_message *message,
24 const char *name);
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27 sd_bus_message_get_type() returns the type of a message in the output
28 parameter type, one of SD_BUS_MESSAGE_METHOD_CALL,
29 SD_BUS_MESSAGE_METHOD_RETURN, SD_BUS_MESSAGE_METHOD_ERROR,
30 SD_BUS_MESSAGE_SIGNAL. This type is either specified as a parameter
31 when the message is created using sd_bus_set_message_new(3), or is set
32 automatically when the message is created using
33 sd_bus_set_message_new_signal(3),
34 sd_bus_set_message_new_method_call(3),
35 sd_bus_set_message_new_method_error(3) and similar functions.
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37 sd_bus_message_is_signal() checks if message m is a signal message. If
38 interface is non-null, it also checks if the message has the same
39 interface set. If member is non-null, it also checks if the message has
40 the same member set. Also see sd_bus_set_message_new_signal(3). It
41 returns true when all checks pass.
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43 sd_bus_message_is_method_call() checks if message m is a method call
44 message. If interface is non-null, it also checks if the message has
45 the same interface set. If member is non-null, it also checks if the
46 message has the same member set. Also see
47 sd_bus_set_message_new_method_call(3). It returns true when all checks
48 pass.
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50 sd_bus_message_is_method_error() checks if message m is an error reply
51 message. If name is non-null, it also checks if the message has the
52 same error identifier set. Also see
53 sd_bus_set_message_new_method_error(3). It returns true when all checks
54 pass.
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57 On success, those functions return 0 or a positive integer. On failure,
58 it returns a negative errno-style error code.
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60 Errors
61 Returned errors may indicate the following problems:
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63 -EINVAL
64 The message parameter or the output parameter are NULL.
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67 These APIs are implemented as a shared library, which can be compiled
68 and linked to with the libsystemd pkg-config(1) file.
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71 systemd(1), sd-bus(3), sd_bus_message_new(3),
72 sd_bus_message_set_destination(3)
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76systemd 245 SD_BUS_MESSAGE_GET_TYPE(3)