X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?a=blobdiff_plain;ds=sidebyside;f=src%2Fsystemctl.c;h=4f4ee961726ed7a6595bab372cc21f2294771e4d;hb=5f7c426e2a7f72c473f98be9978d243db79d8910;hp=585f1dc5fee1d56670a9c0089187a78ead227013;hpb=0736af98c6fae9c7d31e3dd17589421b7e883ef5;p=elogind.git

diff --git a/src/systemctl.c b/src/systemctl.c
index 585f1dc5f..4f4ee9617 100644
--- a/src/systemctl.c
+++ b/src/systemctl.c
@@ -110,11 +110,20 @@ static enum dot {
 
 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;
 
@@ -419,6 +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",
@@ -765,6 +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",
@@ -2475,6 +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 */
@@ -2858,6 +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",
@@ -3220,6 +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",
@@ -4251,7 +4271,7 @@ static int systemctl_parse_argv(int argc, char *argv[]) {
                 ARG_SYSTEM,
                 ARG_GLOBAL,
                 ARG_NO_BLOCK,
-		ARG_NO_PAGER,
+                ARG_NO_PAGER,
                 ARG_NO_WALL,
                 ARG_ORDER,
                 ARG_REQUIRE,
@@ -4352,9 +4372,9 @@ static int systemctl_parse_argv(int argc, char *argv[]) {
                         arg_no_block = true;
                         break;
 
-		case ARG_NO_PAGER:
-			arg_no_pager = true;
-			break;
+                case ARG_NO_PAGER:
+                        arg_no_pager = true;
+                        break;
 
                 case ARG_NO_WALL:
                         arg_no_wall = true;
@@ -5283,45 +5303,78 @@ static int runlevel_main(void) {
 }
 
 static void pager_open(void) {
-	pid_t pid;
-	int fd[2];
-	const char *pager = getenv("PAGER");
-
-	if (!on_tty() || arg_no_pager)
-		return;
-	if (!pager)
-		pager = "less";
-	else if (!*pager || !strcmp(pager, "cat"))
-		return;
-
-	if (pipe(fd) < 0)
-		return;
-	pid = fork();
-	if (pid < 0) {
-		close(fd[0]);
-		close(fd[1]);
-		return;
-	}
-
-	/* Return in the child */
-	if (!pid) {
-		dup2(fd[1], 1);
-		close(fd[0]);
-		close(fd[1]);
-		return;
-	}
-
-	/* The original process turns into the PAGER */
-	dup2(fd[0], 0);
-	close(fd[0]);
-	close(fd[1]);
-
-	setenv("LESS", "FRSX", 0);
-	execlp(pager, pager, NULL);
-	execl("/bin/sh", "sh", "-c", pager, NULL);
-
-	log_error("unable to execute pager '%s'", pager);
-	_exit(EXIT_FAILURE);
+        int fd[2];
+        const char *pager;
+
+        if (pager_pid > 0)
+                return;
+
+        if (!on_tty() || arg_no_pager)
+                return;
+
+        if ((pager = getenv("PAGER")))
+                if (!*pager || streq(pager, "cat"))
+                        return;
+
+        if (pipe(fd) < 0) {
+                log_error("Failed to create pager pipe: %m");
+                return;
+        }
+
+        pager_pid = fork();
+        if (pager_pid < 0) {
+                log_error("Failed to fork pager: %m");
+                close_pipe(fd);
+                return;
+        }
+
+        /* In the child start the pager */
+        if (pager_pid == 0) {
+
+                dup2(fd[0], STDIN_FILENO);
+                close_pipe(fd);
+
+                setenv("LESS", "FRSX", 0);
+
+                prctl(PR_SET_PDEATHSIG, SIGTERM);
+
+                if (pager) {
+                        execlp(pager, pager, NULL);
+                        execl("/bin/sh", "sh", "-c", pager, NULL);
+                } else {
+                        /* 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);
+                }
+
+                log_error("Unable to execute pager: %m");
+                _exit(EXIT_FAILURE);
+        }
+
+        /* Return in the parent */
+        if (dup2(fd[1], STDOUT_FILENO) < 0)
+                log_error("Failed to duplicate pager pipe: %m");
+
+        close_pipe(fd);
+}
+
+static void pager_close(void) {
+        siginfo_t dummy;
+
+        if (pager_pid <= 0)
+                return;
+
+        /* Inform pager that we are done */
+        fclose(stdout);
+        wait_for_terminate(pager_pid, &dummy);
+        pager_pid = 0;
 }
 
 int main(int argc, char*argv[]) {
@@ -5341,8 +5394,6 @@ 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) {
@@ -5406,5 +5457,7 @@ finish:
 
         strv_free(arg_property);
 
+        pager_close();
+
         return retval;
 }