[systemd-devel] [PATCH v2] sd-login: add a public accessor for the VT number

[Giovanni Campagna]

From: Giovanni Campagna <gcampagn at redhat.com>

The VT number was already part of the DBus API, but was not
exposed in the C API.
---
 man/sd_session_is_active.xml   | 13 +++++++++++++
 src/login/libsystemd-login.sym |  5 +++++
 src/login/sd-login.c           | 18 ++++++++++++++++++
 src/systemd/sd-login.h         |  3 +++
 4 files changed, 39 insertions(+)

diff --git a/man/sd_session_is_active.xml b/man/sd_session_is_active.xml
index e89117d..9362fbc 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 0720704..7512ef5 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_206 {
+global:
+        sd_session_get_vt;
+} LIBSYSTEMD_LOGIN_205;
\ No newline at end of file
diff --git a/src/login/sd-login.c b/src/login/sd-login.c
index 0658792..6a6e04e 100644
--- a/src/login/sd-login.c
+++ b/src/login/sd-login.c
@@ -347,6 +347,24 @@ _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;
+        char *end;
+        int r;
+        unsigned long v;
+
+        r = session_get_string(session, "VTNr", &vtnr_string);
+        if (r < 0)
+                return r;
+
+        v = strtoul(vtnr_string, &end, 10);
+        if (end == vtnr_string || *end)
+                return -EINVAL;
+
+        *vtnr = v;
+        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 e37aeda..c5837f0 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);
 
-- 
1.8.3.1