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NAME | SYNOPSIS | DESCRIPTION | RETURN VALUE | NOTES | HISTORY | SEE ALSO | COLOPHON |
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SD_BUS_M...IGNATURE(3) sd_bus_message_get_signatureSD_BUS_M...IGNATURE(3)
sd_bus_message_get_signature, sd_bus_message_is_empty,
sd_bus_message_has_signature - Query bus message signature
#include <systemd/sd-bus.h>
const char* sd_bus_message_get_signature(sd_bus_message *message,
int complete);
int sd_bus_message_is_empty(sd_bus_message *message);
int sd_bus_message_has_signature(sd_bus_message *message,
const char *signature);
sd_bus_message_get_signature() returns the signature of message
message. If complete is true, the signature of the whole message
is returned, and just the signature of the currently open
container otherwise.
sd_bus_message_is_empty() returns true if the message is empty,
i.e. when its signature is empty.
sd_bus_message_has_signature() returns true if the signature of
the message message matches given signature. Parameter signature
may be NULL, this is treated the same as an empty string, which is
equivalent to calling sd_bus_message_is_empty().
On success, sd_bus_message_get_signature() returns the signature,
and NULL on error.
The other functions return 0 or a positive integer on success. On
failure, they return a negative errno-style error code.
Errors
Returned errors may indicate the following problems:
-EINVAL
The message parameter is NULL.
NULL
The message parameter is NULL.
Functions described here are available as a shared library, which
can be compiled against and linked to with the
libsystemd pkg-config(1) file.
The code described here uses getenv(3), which is declared to be
not multi-thread-safe. This means that the code calling the
functions described here must not call setenv(3) from a parallel
thread. It is recommended to only do calls to setenv() from an
early phase of the program when no other threads have been
started.
sd_bus_message_get_signature(), sd_bus_message_is_empty(), and
sd_bus_message_has_signature() were added in version 240.
systemd(1), sd-bus(3), sd_bus_message_new(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 2025-08-11. (At that
time, the date of the most recent commit that was found in the
repository was 2025-08-11.) 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~rc2 SD_BUS_M...IGNATURE(3)
Pages that refer to this page: sd-bus(3), systemd.directives(7), systemd.index(7)
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HTML rendering created 2025-09-06 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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