'\" t
.TH "SD_JOURNAL_QUERY_UNIQUE" "3" "" "elogind 246.9.1" "sd_journal_query_unique"
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.SH "NAME"
sd_journal_query_unique, sd_journal_enumerate_unique, sd_journal_enumerate_available_unique, sd_journal_restart_unique, SD_JOURNAL_FOREACH_UNIQUE \- Read unique data fields from the journal
.SH "SYNOPSIS"
.sp
.ft B
.nf
#include <elogind/sd\-journal\&.h>
.fi
.ft
.HP \w'int\ sd_journal_query_unique('u
.BI "int sd_journal_query_unique(sd_journal\ *" "j" ", const\ char\ *" "field" ");"
.HP \w'int\ sd_journal_enumerate_available_unique('u
.BI "int sd_journal_enumerate_available_unique(sd_journal\ *" "j" ", const\ void\ **" "data" ", size_t\ *" "length" ");"
.HP \w'int\ sd_journal_enumerate_unique('u
.BI "int sd_journal_enumerate_unique(sd_journal\ *" "j" ", const\ void\ **" "data" ", size_t\ *" "length" ");"
.HP \w'void\ sd_journal_restart_unique('u
.BI "void sd_journal_restart_unique(sd_journal\ *" "j" ");"
.HP \w'SD_JOURNAL_FOREACH_UNIQUE('u
.BI "SD_JOURNAL_FOREACH_UNIQUE(sd_journal\ *" "j" ", const\ void\ *" "data" ", size_t\ " "length" ");"
.SH "DESCRIPTION"
.PP
\fBsd_journal_query_unique()\fR
is not needed in elogind and does nothing\&.
.PP
\fBsd_journal_enumerate_unique()\fR
can not do anything in elogind, as there is no systemd\-journal on elogind powered systems\&.
.PP
\fBsd_journal_restart_unique()\fR
resets the data enumeration index to the beginning of the list, which effectively does nothing\&.
.PP
Note that the
\fBSD_JOURNAL_FOREACH_UNIQUE()\fR
macro will therefore never do anything\&.
.SH "RETURN VALUE"
.PP
\fBsd_journal_query_unique()\fR
returns 0 on success or a negative errno\-style error code\&.
\fBsd_journal_enumerate_unique()\fR
and and

\fBsd_journal_query_available_unique()\fR
always return 0\&.

\fBsd_journal_restart_unique()\fR
doesn\*(Aqt return anything\&.
.SH "NOTES"
.PP
These APIs are implemented as a shared library, which can be compiled and linked to with the
\fBlibelogind\fR\ \&\fBpkg-config\fR(1)
file\&.
.SH "SEE ALSO"
.PP

\fBelogind\fR(8),
\fBelogind.journal-fields\fR(7),

\fBsd_journal_open\fR(3),
\fBsd_journal_enumerate_fields\fR(3),
\fBsd_journal_get_data\fR(3),
\fBsd_journal_add_match\fR(3)