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NAME |SYNOPSIS |DESCRIPTION |RETURN VALUE |NOTES |SEE ALSO |NOTES |COLOPHON | |
SD_BUS..._MEMFD(3) sd_bus_message_append_string_memfdSD_BUS..._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,intmemfd);int sd_bus_message_append_string_iovec(sd_bus_message *m,const struct iovec *iov,unsignedn);int sd_bus_message_append_string_space(sd_bus_message *m,size_tsize, char **s);
The functionssd_bus_message_append_string_memfd()andsd_bus_message_append_string_iovec()can be used to append a single string (item of type "s") to messagem. In case ofsd_bus_message_append_string_memfd(), the contents ofmemfd are the string. They must satisfy the same constraints as described for the "s" type insd_bus_message_append_basic(3). In case ofsd_bus_message_append_string_iovec(), the payload ofiov is the string. It must satisfy the same constraints as described for the "s" type insd_bus_message_append_basic(3). Theiov argument must point ton 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 byiov may be changed after this call. Thesd_bus_message_append_string_space()function appends space for a string to messagem. It behaves similar tosd_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 pointerp. Space for the string of lengthsize plus the terminatingNULis allocated.
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.
Functions described here are available as a shared library, which can be compiled against and linked to with thelibsystemd pkg-config(1) file. The code described here usesgetenv(3), which is declared to be not multi-thread-safe. This means that the code calling the functions described here must not callsetenv(3) from a parallel thread. It is recommended to only do calls tosetenv()from an early phase of the program when no other threads have been started.
systemd(1),sd-bus(3),sd_bus_message_append_basic(3),The D-Busspecification[1]
1. The D-Bus specificationhttps://dbus.freedesktop.org/doc/dbus-specification.html
This page is part of thesystemd (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 isnot part of the original manual page), send a mail to man-pages@man7.orgsystemd 258~rc2SD_BUS..._MEMFD(3)Pages that refer to this page:sd-bus(3), systemd.directives(7), systemd.index(7)
HTML rendering created 2025-09-06 byMichael Kerrisk, author ofThe Linux Programming Interface. For details of in-depthLinux/UNIX system programming training courses that I teach, lookhere. Hosting byjambit GmbH. | |