Improve logic

lib/python/rose/popen.py

@@ -190,6 +190,33 @@ def run_bg(self, *args, **kwargs):
             raise RosePopenError(args, 1, "", str(exc))
         return proc
 
+    def run_nohup_gui(self, cmd):
+        """Launch+detach a GUI command with nohup.
+
+        Launch the GUI command with `nohup bash -c 'exec ...'` redirecting
+        standard input and outputs from and to `/dev/null`, and setting it to
+        become a process group leader. Equivalent to a double fork.
+
+        Arguments:
+            cmd (str): command string of the GUI.
+
+        Return (subprocess.Popen):
+            Return the process object for the "nohup" command.
+            Return None if no DISPLAY is set.
+        """
+        if 'DISPLAY' not in os.environ:
+            return
+        return self.run_bg(
+            r'nohup',
+            r'bash',
+            r'-c',
+            r'exec ' + cmd + r' <"/dev/null" >"/dev/null" 2>&1',
+            preexec_fn=os.setpgrp,
+            stdin=open(os.devnull),
+            stdout=open(os.devnull, "wb"),
+            stderr=open(os.devnull, "wb"),
+        )
+
     def run_ok(self, *args, **kwargs):
         """Same as RosePopener.run, but raise RosePopenError if ret_code != 1.
 

lib/python/rose/suite_engine_procs/cylc.py

@@ -132,39 +132,18 @@ def cmp_suite_conf(
 
     def gcontrol(self, suite_name, args=None):
         """Launch control GUI for a suite_name."""
-        if 'DISPLAY' not in os.environ:
-            return
-        cylc_version = (
-            self.get_suite_contact(suite_name).get('CYLC_VERSION', ''))
-        self.popen.run_bg(
-            r'nohup',
-            r'bash',
-            r'-c',
-            (
-                r'exec env CYLC_VERSION=%s cylc gui %s %s' +
-                r' <"/dev/null" >"/dev/null" 2>&1'
-            ) % (cylc_version, suite_name, self.popen.list_to_shell_str(args)),
-            preexec_fn=os.setpgrp,
-            stdin=open(os.devnull),
-            stdout=open(os.devnull, "wb"),
-            stderr=open(os.devnull, "wb"),
+        return self.popen.run_nohup_gui(
+            r'env CYLC_VERSION=%s cylc gui %s %s' % (
+                self.get_suite_contact(suite_name).get('CYLC_VERSION', ''),
+                suite_name,
+                self.popen.list_to_shell_str(args),
+            )
         )
 
     def gscan(self, args=None):
         """Launch suites scan GUI."""
-        if 'DISPLAY' not in os.environ:
-            return
-        args_str = self.popen.list_to_shell_str(args)
-        self.popen.run_bg(
-            r'nohup',
-            r'bash',
-            r'-c',
-            r'exec cylc gscan %s <"/dev/null" >"/dev/null" 2>&1' % (args_str),
-            preexec_fn=os.setpgrp,
-            stdin=open(os.devnull),
-            stdout=open(os.devnull, "wb"),
-            stderr=open(os.devnull, "wb"),
-        )
+        return self.popen.run_nohup_gui(
+            r'cylc gscan %s' % (self.popen.list_to_shell_str(args),))
 
     def get_running_suites(self):
         """Return a list containing the names of running suites."""
@@ -173,7 +152,7 @@ def get_running_suites(self):
         items = []
         for dirpath, dnames, fnames in os.walk(rootd, followlinks=True):
             if dirpath != rootd and any(
-                    name in dnames or name in fnames for name in sub_names):
+                    name in dnames + fnames for name in sub_names):
                 dnames[:] = []
             else:
                 continue