sd-login: add a public accessor for the VT number

The VT number was already part of the DBus API, but was not
exposed in the C API.

5 files changed, 43 insertions, 0 deletions

diff --git a/Makefile-man.am b/Makefile-man.am
index 1c264fa3fb..1f635956e2 100644
--- a/Makefile-man.am
+++ b/Makefile-man.am
@@ -854,6 +854,7 @@ MANPAGES_ALIAS += \
 	man/sd_session_get_tty.3 \
 	man/sd_session_get_type.3 \
 	man/sd_session_get_uid.3 \
+	man/sd_session_get_vt.3 \
 	man/sd_uid_get_seats.3 \
 	man/sd_uid_get_sessions.3 \
 	man/sd_uid_is_on_seat.3 \
@@ -882,6 +883,7 @@ man/sd_session_get_state.3: man/sd_session_is_active.3
 man/sd_session_get_tty.3: man/sd_session_is_active.3
 man/sd_session_get_type.3: man/sd_session_is_active.3
 man/sd_session_get_uid.3: man/sd_session_is_active.3
+man/sd_session_get_vt.3: man/sd_session_is_active.3
 man/sd_uid_get_seats.3: man/sd_uid_get_state.3
 man/sd_uid_get_sessions.3: man/sd_uid_get_state.3
 man/sd_uid_is_on_seat.3: man/sd_uid_get_state.3
@@ -958,6 +960,9 @@ man/sd_session_get_type.html: man/sd_session_is_active.html
 man/sd_session_get_uid.html: man/sd_session_is_active.html
 	$(html-alias)
 
+man/sd_session_get_vt.html: man/sd_session_is_active.html
+	$(html-alias)
+
 man/sd_uid_get_seats.html: man/sd_uid_get_state.html
 	$(html-alias)
 
diff --git a/man/sd_session_is_active.xml b/man/sd_session_is_active.xml
index e89117d990..9362fbcc55 100644
--- a/man/sd_session_is_active.xml
+++ b/man/sd_session_is_active.xml
@@ -52,6 +52,7 @@
                 <refname>sd_session_get_class</refname>
                 <refname>sd_session_get_display</refname>
                 <refname>sd_session_get_tty</refname>
+                <refname>sd_session_get_vt</refname>
                 <refpurpose>Determine state of a specific session</refpurpose>
         </refnamediv>
 
@@ -111,6 +112,12 @@
                                 <paramdef>const char* <parameter>session</parameter></paramdef>
                                 <paramdef>char** <parameter>tty</parameter></paramdef>
                         </funcprototype>
+
+                        <funcprototype>
+                                <funcdef>int <function>sd_session_get_vt</function></funcdef>
+                                <paramdef>const char* <parameter>session</parameter></paramdef>
+                                <paramdef>unsigned* <parameter>vt</parameter></paramdef>
+                        </funcprototype>
                 </funcsynopsis>
         </refsynopsisdiv>
 
@@ -202,6 +209,12 @@
                 <citerefentry><refentrytitle>free</refentrytitle><manvolnum>3</manvolnum></citerefentry>
                 call after use.</para>
 
+                <para><function>sd_session_get_vt()</function>
+                may be used to determine the VT number of the
+                session identified by the specified session
+                identifier. This function will return an error if
+                the seat does not support VTs.</para>
+
                 <para>If the <varname>session</varname> parameter of
                 any of these functions is passed as
                 <constant>NULL</constant> the operation is executed
diff --git a/src/login/libsystemd-login.sym b/src/login/libsystemd-login.sym
index 0720704dbf..54aa91c609 100644
--- a/src/login/libsystemd-login.sym
+++ b/src/login/libsystemd-login.sym
@@ -80,3 +80,8 @@ LIBSYSTEMD_LOGIN_205 {
 global:
         sd_pid_get_slice;
 } LIBSYSTEMD_LOGIN_203;
+
+LIBSYSTEMD_LOGIN_207 {
+global:
+        sd_session_get_vt;
+} LIBSYSTEMD_LOGIN_205;
diff --git a/src/login/sd-login.c b/src/login/sd-login.c
index 06587921cd..8a7838d566 100644
--- a/src/login/sd-login.c
+++ b/src/login/sd-login.c
@@ -347,6 +347,23 @@ _public_ int sd_session_get_tty(const char *session, char **tty) {
         return session_get_string(session, "TTY", tty);
 }
 
+_public_ int sd_session_get_vt(const char *session, unsigned *vtnr) {
+        _cleanup_free_ char *vtnr_string;
+        unsigned u;
+        int r;
+
+        r = session_get_string(session, "VTNr", &vtnr_string);
+        if (r < 0)
+                return r;
+
+        r = safe_atou(vtnr_string, &u);
+        if (r < 0)
+                return r;
+
+        *vtnr = u;
+        return 0;
+}
+
 _public_ int sd_session_get_service(const char *session, char **service) {
         return session_get_string(session, "SERVICE", service);
 }
diff --git a/src/systemd/sd-login.h b/src/systemd/sd-login.h
index e37aeda2bb..c5837f0ca0 100644
--- a/src/systemd/sd-login.h
+++ b/src/systemd/sd-login.h
@@ -124,6 +124,9 @@ int sd_session_get_display(const char *session, char **display);
 /* Determine the TTY of this session. */
 int sd_session_get_tty(const char *session, char **display);
 
+/* Determine the VT number of this session. */
+int sd_session_get_vt(const char *session, unsigned *vtnr);
+
 /* Return active session and user of seat */
 int sd_seat_get_active(const char *seat, char **session, uid_t *uid);