Man page - sd_bus_message_append_string_memfd(3)

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Manual

SD_BUS_MESSAGE_APPEND_STRING_MEMFD

NAME
SYNOPSIS
DESCRIPTION
RETURN VALUE
Errors
NOTES
SEE ALSO
NOTES

NAME

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

SYNOPSIS

#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

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.

RETURN VALUE

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

Errors

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.

NOTES

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.

SEE ALSO

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

NOTES

1.

The D-Bus specification

https://dbus.freedesktop.org/doc/dbus-specification.html