| SD_BUS_MESSAGE_READ_STRV(3) | sd_bus_message_read_strv | SD_BUS_MESSAGE_READ_STRV(3) |
.SH "NAME" sd_bus_message_read_strv,
sd_bus_message_read_strv_extend - Access an array of strings in a
message
.SH "SYNOPSIS"
#include <systemd/sd-bus.h>
.HP 696u int
sd_bus_message_read_strv(sd_bus_message *m,
char ***l);
.HP 864u int
sd_bus_message_read_strv_extend(sd_bus_message *m,
char ***l);
.SH "DESCRIPTION"
.PP sd_bus_message_read_strv() reads an array of string-like items
from the message m. The "read pointer" in the message must
be right before an array of strings (D-Bus type as), object paths (D-Bus
type ao), or signatures (D-Bus type ag). On success, a pointer to a
NULL-terminated array of strings (strv) is returned in the output
parameter l. Note that ownership of this array is transferred to the
caller. Hence, the caller is responsible for freeing this array and its
contents. Also note that as a matter of optimization, if an empty array is
encountered a NULL pointer might be returned here, and should be
considered equivalent to an array with zero entries.
.PP sd_bus_message_read_strv_extend() is similar, but the second
parameter is an input-output parameter. If *l is NULL, if
behaves identically to sd_bus_message_read_strv(). Otherwise,
*l must point to a strv, which will be reallocated and extended with
additional strings. This function is particularly useful when combining
multiple lists of strings in a message or messages into a single array of
strings.
.SH "RETURN VALUE"
.PP On success, these functions return a non-negative integer. On failure,
they return a negative errno-style error code.
.SS "Errors"
.PP Returned errors may indicate the following problems:
.PP -EINVAL
m or l are NULL.
Added in version 246.
.RE
.PP -EPERM
The message is not sealed.
Added in version 246.
.RE
.PP -EBADMSG
The message cannot be parsed.
Added in version 246.
.RE
.PP -ENXIO
The message "read pointer" is not right before an array of the
appropriate type.
Added in version 248.
.RE
.SH "NOTES"
.PP Functions described here are available as a shared library, which can be
compiled against and linked to with the
libsystemd pkg-config(1) file.
.PP All functions listed here are thread-agnostic and only a single thread
may operate on a given object at any given time. Different threads may
access the same object at different times. Multiple independent objects may
be used from different threads in parallel.
.PP 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.
.SH "HISTORY"
.PP sd_bus_message_read_strv() was added in version 246.
.PP sd_bus_message_read_strv_extend() was added in version 252.
.SH "SEE ALSO"
| systemd 262.2 |