'\" t .\" Title: sd_seat_get_active .\" Author: Lennart Poettering .\" Generator: DocBook XSL Stylesheets v1.76.1 .\" Date: 10/07/2013 .\" Manual: sd_seat_get_active .\" Source: systemd .\" Language: English .\" .TH "SD_SEAT_GET_ACTIVE" "3" "10/07/2013" "systemd" "sd_seat_get_active" .\" ----------------------------------------------------------------- .\" * Define some portability stuff .\" ----------------------------------------------------------------- .\" ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ .\" http://bugs.debian.org/507673 .\" http://lists.gnu.org/archive/html/groff/2009-02/msg00013.html .\" ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ .ie \n(.g .ds Aq \(aq .el .ds Aq ' .\" ----------------------------------------------------------------- .\" * set default formatting .\" ----------------------------------------------------------------- .\" disable hyphenation .nh .\" disable justification (adjust text to left margin only) .ad l .\" ----------------------------------------------------------------- .\" * MAIN CONTENT STARTS HERE * .\" ----------------------------------------------------------------- .SH "NAME" sd_seat_get_active, sd_seat_get_sessions, sd_seat_can_multi_session \- Determine state of a specific seat .SH "SYNOPSIS" .sp .ft B .nf #include .fi .ft .HP \w'int\ sd_seat_get_active('u .BI "int sd_seat_get_active(const\ char*\ " "seat" ", char**\ " "session" ", uid_t*\ " "uid" ");" .HP \w'int\ sd_seat_get_sessions('u .BI "int sd_seat_get_sessions(const\ char*\ " "seat" ", char***\ " "sessions" ", uid_t**\ " "uid" ", unsigned*\ " "n_uids" ");" .HP \w'int\ sd_seat_can_multi_session('u .BI "int sd_seat_can_multi_session(const\ char*\ " "seat" ");" .SH "DESCRIPTION" .PP \fBsd_seat_get_active()\fR may be used to determine which session is currently active on a seat, if there is any\&. Returns the session identifier and the user identifier of the Unix user the session is belonging to\&. Either the session or the user identifier parameter can be be passed NULL, in case only one of the parameters shall be queried\&. The returned string needs to be freed with the libc \fBfree\fR(3) call after use\&. .PP \fBsd_seat_get_sessions()\fR may be used to determine all sessions on the specified seat\&. Returns two arrays, one (NULL terminated) with the session identifiers of the sessions and one with the user identifiers of the Unix users the sessions belong to\&. An additional parameter may be used to return the number of entries in the latter array\&. The two arrays and the latter parameter may be passed as NULL in case these values need not to be determined\&. The arrays and the strings referenced by them need to be freed with the libc \fBfree\fR(3) call after use\&. Note that instead of an empty array NULL may be returned and should be considered equivalent to an empty array\&. .PP \fBsd_seat_can_multi_session()\fR may be used to determine whether a specific seat is capable of multi\-session, i\&.e\&. allows multiple login sessions in parallel (whith only one being active at a time)\&. .PP If the seat parameter of any of these functions is passed as NULL the operation is executed for the seat of the session of the calling process, if there is any\&. .SH "RETURN VALUE" .PP On success \fBsd_seat_get_active()\fR return return 0 or a positive integer\&. On success \fBsd_seat_get_sessions()\fR returns the number of entries in the session identifier array\&. If the test succeeds \fBsd_seat_can_multi_session\fR returns a positive integer, if it fails 0\&. On failure, these calls return a negative errno\-style error code\&. .SH "NOTES" .PP The \fBsd_seat_get_active()\fR, \fBsd_seat_get_sessions()\fR, and \fBsd_seat_can_multi_session()\fR interfaces are available as shared library, which can be compiled and linked to with the libsystemd\-login \fBpkg-config\fR(1) file\&. .SH "SEE ALSO" .PP \fBsystemd\fR(1), \fBsd-login\fR(7), \fBsd_session_get_seat\fR(3) .SH "AUTHOR" .PP \fBLennart Poettering\fR <\&lennart@poettering\&.net\&> .RS 4 Developer .RE