1SD_BUS_IS_OPEN(3)               sd_bus_is_open               SD_BUS_IS_OPEN(3)
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NAME

6       sd_bus_is_open, sd_bus_is_ready - Check whether the bus connection is
7       open or ready
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SYNOPSIS

10       #include <systemd/sd-bus.h>
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12       int sd_bus_is_open(sd_bus *bus);
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14       int sd_bus_is_ready(sd_bus *bus);
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DESCRIPTION

17       sd_bus_is_open() checks whether the specified bus connection is open,
18       i.e. in the process of being established, already established or in the
19       process of being torn down. It returns zero when the connection has not
20       been started yet (i.e.  sd_bus_start(3) or some equivalent call has not
21       been invoked yet), or is fully terminated again (for example after
22       sd_bus_close(3)), it returns positive otherwise.
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24       sd_bus_is_ready() checks whether the specified connection is fully
25       established, i.e. completed the connection and authentication phases of
26       the protocol and received the Hello() method call response, and is not
27       in the process of being torn down again. It returns zero outside of
28       this state, and positive otherwise. Effectively, this function returns
29       positive while regular messages can be sent or received on the
30       connection.
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32       The bus argument may be NULL, zero is also returned in that case.
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34       To be notified when the connection is fully established, use
35       sd_bus_set_connected_signal(3) and install a match for the Connected()
36       signal on the "org.freedesktop.DBus.Local" interface. To be notified
37       when the connection is torn down again, install a match for the
38       Disconnected() signal on the "org.freedesktop.DBus.Local" interface.
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RETURN VALUE

41       Those functions return 0 if the bus is not in the given state, and a
42       positive integer when it is. On failure, a negative errno-style error
43       code is returned.
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45   Errors
46       Returned errors may indicate the following problems:
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48       -ECHILD
49           The bus connection has been created in a different process, library
50           or module instance.
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NOTES

53       Functions described here are available as a shared library, which can
54       be compiled against and linked to with the libsystemd pkg-config(1)
55       file.
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57       The code described here uses getenv(3), which is declared to be not
58       multi-thread-safe. This means that the code calling the functions
59       described here must not call setenv(3) from a parallel thread. It is
60       recommended to only do calls to setenv() from an early phase of the
61       program when no other threads have been started.
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SEE ALSO

64       systemd(1), sd-bus(3), sd_bus_start(3), sd_bus_close(3),
65       sd_bus_set_connected_signal(3)
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69systemd 254                                                  SD_BUS_IS_OPEN(3)
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