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NAME | SYNOPSIS | DESCRIPTION | RETURN VALUE | HISTORY | SEE ALSO | COLOPHON |
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SD_BUS_M...EAD_ARRAY(3) sd_bus_message_read_array SD_BUS_M...EAD_ARRAY(3)
sd_bus_message_read_array - Access an array of elements in a
message
#include <systemd/sd-bus.h>
int sd_bus_message_read_array(sd_bus_message *m, char type,
const void **ptr, size_t *size);
sd_bus_message_read_array() provides access to an array elements
in the bus message m. The "read pointer" in the message must be
right before an array of type type. As a special case, type may be
NUL, in which case any trivial type is acceptable. A pointer to
the array data is returned in the parameter ptr and the size of
array data (in bytes) is returned in the parameter size. If the
returned size parameter is 0, a valid non-null pointer will be
returned as ptr, but it may not be dereferenced. The data is
aligned as appropriate for the data type. The data is part of the
message — it may not be modified and is valid only as long as the
message is referenced. After this function returns, the "read
pointer" points at the next element after the array.
Note that this function only supports arrays of trivial types,
i.e. arrays of booleans, the various integer types, as well as
floating point numbers. In particular it may not be used for
arrays of strings, structures or similar.
On success and when an array was read, sd_bus_message_read_array()
returns an integer greater than zero. If invoked while inside a
container element (such as an array, e.g. when operating on an
array of arrays) and the final element of the outer container has
been read already and the read pointer is thus behind the last
element of the outer container this call returns 0 (and the
returned pointer will be NULL and the size will be 0). On failure,
it returns a negative errno-style error code.
Errors
Returned errors may indicate the following problems:
-EINVAL
Specified type is invalid or not a trivial type (see above),
or the message parameter or one of the output parameters are
NULL.
-EOPNOTSUPP
The byte order in the message is different than native byte
order.
-EPERM
The message is not sealed.
-EBADMSG
The message cannot be parsed.
sd_bus_message_read_array() was added in version 240.
systemd(1), sd-bus(3), sd_bus_message_read(3),
sd_bus_message_read_strv(3)
This page is part of the systemd (systemd system and service
manager) project. Information about the project can be found at
⟨http://www.freedesktop.org/wiki/Software/systemd⟩. If you have a
bug report for this manual page, see
⟨http://www.freedesktop.org/wiki/Software/systemd/#bugreports⟩.
This page was obtained from the project's upstream Git repository
⟨https://github.com/systemd/systemd.git⟩ on 2025-02-02. (At that
time, the date of the most recent commit that was found in the
repository was 2025-02-02.) If you discover any rendering
problems in this HTML version of the page, or you believe there is
a better or more up-to-date source for the page, or you have
corrections or improvements to the information in this COLOPHON
(which is not part of the original manual page), send a mail to
man-pages@man7.org
systemd 258~devel SD_BUS_M...EAD_ARRAY(3)
Pages that refer to this page: sd-bus(3), systemd.directives(7), systemd.index(7)
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HTML rendering created 2025-02-02 by Michael Kerrisk, author of The Linux Programming Interface. For details of in-depth Linux/UNIX system programming training courses that I teach, look here. Hosting by jambit GmbH. |
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