1SD_BUS_WAIT(3)                    sd_bus_wait                   SD_BUS_WAIT(3)
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NAME

6       sd_bus_wait - Wait for I/O on a bus connection
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SYNOPSIS

9       #include <systemd/sd-bus.h>
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11       int sd_bus_wait(sd_bus *bus, uint64_t timeout_usec);
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DESCRIPTION

14       sd_bus_wait() synchronously waits for I/O on the specified bus
15       connection object. This function is supposed to be called whenever
16       sd_bus_process(3) returns zero, indicating that no work is pending on
17       the connection. Internally, this call invokes ppoll(2), to wait for I/O
18       on the bus connection. If the timeout_usec parameter is specified, the
19       call will block at most for the specified amount of time in µs. Pass
20       UINT64_MAX to permit it to sleep indefinitely.
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22       After each invocation of sd_bus_wait() the sd_bus_process() call should
23       be invoked in order to process any now pending I/O work.
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25       Note that sd_bus_wait() is suitable only for simple programs as it does
26       not permit waiting for other I/O events. For more complex programs
27       either connect the bus connection object to an external event loop
28       using sd_bus_get_fd(3) or to an sd-event(3) event loop using
29       sd_bus_attach_event(3).
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RETURN VALUE

32       If any I/O was seen, a positive value is returned, zero otherwise. If
33       an error occurs, a negative errno-style error code is returned.
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35   Errors
36       Returned errors may indicate the following problems:
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38       -EINVAL
39           An invalid bus object was passed.
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41       -ECHILD
42           The bus connection was allocated in a parent process and is being
43           reused in a child process after fork().
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45       -ENOTCONN
46           The bus connection has been terminated already.
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NOTES

49       These APIs are implemented as a shared library, which can be compiled
50       and linked to with the libsystemd pkg-config(1) file.
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SEE ALSO

53       systemd(1), sd-bus(3), sd_bus_process(3), sd_bus_get_fd(3), sd-
54       event(3), sd_bus_attach_event(3)
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58systemd 253                                                     SD_BUS_WAIT(3)
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