sd_bus_message_append_string_memfd(3) — Linux manual page



NAME         top

       sd_bus_message_append_string_space - Attach a string to a message

SYNOPSIS         top

       #include <systemd/sd-bus.h>

       int sd_bus_message_append_string_memfd(sd_bus_message *m,
                                              int memfd);

       int sd_bus_message_append_string_iovec(sd_bus_message *m,
                                              const struct iovec *iov,
                                              unsigned n);

       int sd_bus_message_append_string_space(sd_bus_message *m,
                                              size_t size, char **s);

DESCRIPTION         top

       The functions sd_bus_message_append_string_memfd() and
       sd_bus_message_append_string_iovec() can be used to append a
       single string (item of type "s") to message m.

       In case of sd_bus_message_append_string_memfd(), the contents of
       memfd are the string. They must satisfy the same constraints as
       described for the "s" type in sd_bus_message_append_basic(3).

       In case of sd_bus_message_append_string_iovec(), the payload of
       iov is the string. It must satisfy the same constraints as
       described for the "s" type in sd_bus_message_append_basic(3).

       The iov argument must point to n struct iovec structures. Each
       structure may have the iov_base field set, in which case the
       memory pointed to will be copied into the message, or unset, in
       which case a block of spaces (ASCII 32) of length iov_len will be
       inserted. The memory pointed at by iov may be changed after this

       The sd_bus_message_append_string_space() function appends space
       for a string to message m. It behaves similar to
       sd_bus_message_append_basic() with type "s", but instead of
       copying a string into the message, it returns a pointer to the
       destination area to the caller in pointer p. Space for the string
       of length size plus the terminating NUL is allocated.

RETURN VALUE         top

       On success, those calls return 0 or a positive integer. On
       failure, they return a negative errno-style error code.

       Returned errors may indicate the following problems:

           Specified parameter is invalid.

           Message has been sealed.

           Message is in invalid state.

           Message cannot be appended to.

           Memory allocation failed.

NOTES         top

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

SEE ALSO         top

       systemd(1), sd-bus(3), sd_bus_message_append_basic(3), The D-Bus

NOTES         top

        1. The D-Bus specification

COLOPHON         top

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systemd 249                        SD_BUS_MESSAGE_APPEND_STRING_MEMFD(3)

Pages that refer to this page: sd-bus(3)