systemctl: before spawning pager cache number of columns

[elogind.git] / src / systemctl.c

diff --git a/src/systemctl.c b/src/systemctl.c
index 59ea7490e767dfa879e3673a7875a9d4b2654e77..2c8c2cf61d5165036beffe54ec8784a67dc0a2e1 100644 (file)
--- a/src/systemctl.c
+++ b/src/systemctl.c
@@ -113,10 +113,17 @@ static bool private_bus = false;
 static pid_t pager_pid = 0;
 
 static int daemon_reload(DBusConnection *bus, char **args, unsigned n);
+static void pager_open(void);
 
 static bool on_tty(void) {
         static int t = -1;
 
+        /* Note that this is invoked relatively early, before we start
+         * the pager. That means the value we return reflects whether
+         * we originally were started on a tty, not if we currently
+         * are. But this is intended, since we want color, and so on
+         * when run in our own pager. */
+
         if (_unlikely_(t < 0))
                 t = isatty(STDOUT_FILENO) > 0;
 
@@ -421,6 +428,8 @@ static int list_units(DBusConnection *bus, char **args, unsigned n) {
 
         assert(bus);
 
+        pager_open();
+
         if (!(m = dbus_message_new_method_call(
                               "org.freedesktop.systemd1",
                               "/org/freedesktop/systemd1",
@@ -767,6 +776,8 @@ static int list_jobs(DBusConnection *bus, char **args, unsigned n) {
 
         assert(bus);
 
+        pager_open();
+
         if (!(m = dbus_message_new_method_call(
                               "org.freedesktop.systemd1",
                               "/org/freedesktop/systemd1",
@@ -2477,6 +2488,9 @@ static int show(DBusConnection *bus, char **args, unsigned n) {
 
         show_properties = !streq(args[0], "status");
 
+        if (show_properties)
+                pager_open();
+
         if (show_properties && n <= 1) {
                 /* If not argument is specified inspect the manager
                  * itself */
@@ -2860,6 +2874,8 @@ static int dump(DBusConnection *bus, char **args, unsigned n) {
 
         dbus_error_init(&error);
 
+        pager_open();
+
         if (!(m = dbus_message_new_method_call(
                               "org.freedesktop.systemd1",
                               "/org/freedesktop/systemd1",
@@ -3222,6 +3238,8 @@ static int show_enviroment(DBusConnection *bus, char **args, unsigned n) {
 
         dbus_error_init(&error);
 
+        pager_open();
+
         if (!(m = dbus_message_new_method_call(
                               "org.freedesktop.systemd1",
                               "/org/freedesktop/systemd1",
@@ -5298,6 +5316,10 @@ static void pager_open(void) {
                 if (!*pager || streq(pager, "cat"))
                         return;
 
+        /* Determine and cache number of columns before we spawn the
+         * pager so that we get the value from the actual tty */
+        columns();
+
         if (pipe(fd) < 0) {
                 log_error("Failed to create pager pipe: %m");
                 return;
@@ -5316,8 +5338,7 @@ static void pager_open(void) {
                 dup2(fd[0], STDIN_FILENO);
                 close_pipe(fd);
 
-                if (!getenv("LESS"))
-                        setenv("LESS", "FRSX", 0);
+                setenv("LESS", "FRSX", 0);
 
                 prctl(PR_SET_PDEATHSIG, SIGTERM);
 
@@ -5325,7 +5346,14 @@ static void pager_open(void) {
                         execlp(pager, pager, NULL);
                         execl("/bin/sh", "sh", "-c", pager, NULL);
                 } else {
-                        execlp("sensible-pager", "sensible-pager", NULL);
+                        /* Debian's alternatives command for pagers is
+                         * called 'pager'. Note that we do not call
+                         * sensible-pagers here, since that is just a
+                         * shell script that implements a logic that
+                         * is similar to this one anyway, but is
+                         * Debian-specific. */
+                        execlp("pager", "pager", NULL);
+
                         execlp("less", "less", NULL);
                         execlp("more", "more", NULL);
                 }
@@ -5370,8 +5398,6 @@ int main(int argc, char*argv[]) {
                 goto finish;
         }
 
-        pager_open();
-
         /* /sbin/runlevel doesn't need to communicate via D-Bus, so
          * let's shortcut this */
         if (arg_action == ACTION_RUNLEVEL) {