check whether xvfb is installed

finstrip_wrapper/core/main.py

@@ -6,6 +6,11 @@ import commands
 import sys
 
 
+def cmd_exists(cmd):
+    return subprocess.call("type " + cmd, shell=True,
+                           stdout=subprocess.PIPE, stderr=subprocess.PIPE) == 0
+
+
 class FINSTRIPWrapper(object):
     '''
     A basic wrapper for FINSTRIP that provides three primary functionalities:
@@ -76,6 +81,11 @@ class FINSTRIPWrapper(object):
         '''
         status('FINSTRIPWrapper: Start FINSTRIP execution')
 
+        # check if xvfb is installed
+        if not cmd_exists('xvfb-run'):
+            raise RuntimeError(
+                'xvfb is not installed on the system. Please do sudo apt-get install xvfb')
+
         self.finstrip_work_dir = os.getcwd()
         # create execution command
         cmd_list = [