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SD_BUS_MESSAGE_APPEND_STRING_MEMFD(3) sd_bus_message_append_string_memfd SD_BUS_MESSAGE_APPEND_STRING_MEMFD(3)

sd_bus_message_append_string_memfd, sd_bus_message_append_string_iovec, sd_bus_message_append_string_space - Attach a string to a message

#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);

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 call.

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.

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:

-EINVAL

Specified parameter is invalid.

-EPERM

Message has been sealed.

-ESTALE

Message is in invalid state.

-ENXIO

Message cannot be appended to.

-ENOMEM

Memory allocation failed.

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

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

1.
The D-Bus specification
http://dbus.freedesktop.org/doc/dbus-specification.html
systemd 244