diff --git a/python/install.py b/python/install.py
index c1e62fc853174175e0575584d328edb509bebe89..e1fa4612b4fa4adfc51532f1a7addd5655955f9e 100644
--- a/python/install.py
+++ b/python/install.py
@@ -1,52 +1,67 @@
-#!/usr/bin/env python
+#!/usr/local/bin/python
 
-instructions = """copy LAMMPS shared library src/liblammps.so and lammps.py to system dirs
-Syntax: python install.py [libdir] [pydir]
-    libdir = target dir for src/liblammps.so, default = /usr/local/lib, or the first
-        item in LD_LIBRARY_PATH if it doesn't exist.
-    pydir = target dir for lammps.py, default = Python site-packages, via distutils."""
+# copy LAMMPS src/liblammps.so and lammps.py to system dirs
 
-import sys, shutil, os
+instructions = """
+Syntax: python install.py [-h] [libdir] [pydir]
+        libdir = target dir for src/liblammps.so, default = /usr/local/lib
+        pydir = target dir for lammps.py, default = Python site-packages dir
+"""
 
-if len(sys.argv) > 3:
+import sys,os,commands
+
+if (len(sys.argv) > 1 and sys.argv[1] == "-h") or len(sys.argv) > 3:
   print instructions
   sys.exit()
 
-# verify that our user-specified path is in LD_LIBRARY_PATH
-# since if not, the install won't work
-  
-libdir = "/usr/local/lib"
-libpaths = os.environ['LD_LIBRARY_PATH'].split(':')
-if not libdir in libpaths:
-    libdir = libpaths[0]
+if len(sys.argv) >= 2: libdir = sys.argv[1]
+else: libdir = "/usr/local/lib"
+
+if len(sys.argv) == 3: pydir = sys.argv[2]
+else: pydir = ""
 
-pydir = False
-try:
-    libdir = sys.argv[1]
-    pydir = sys.argv[2]
-except IndexError:
-    pass
+# copy C lib to libdir if it exists
+# warn if not in LD_LIBRARY_PATH or LD_LIBRARY_PATH is undefined
 
-# copy the C library into place
+if not os.path.isdir(libdir):
+  print "ERROR: libdir %s does not exist" % libdir
+  sys.exit()
+  
+if "LD_LIBRARY_PATH" not in os.environ:
+  print "WARNING: LD_LIBRARY_PATH undefined, cannot check libdir %s" % libdir
+else:
+  libpaths = os.environ['LD_LIBRARY_PATH'].split(':')
+  if libdir not in libpaths:
+    print "WARNING: libdir %s not in LD_LIBRARY_PATH" % libdir
 
-shutil.copy('../src/liblammps.so', libdir)
+str = "cp ../src/liblammps.so %s" % libdir
+print str
+outstr = commands.getoutput(str)
+if len(outstr.strip()): print outstr
 
-# if user-specified, copy lammps.py into directory
-# else invoke setup from Distutils to add to site-packages
+# copy lammps.py to pydir if it exists
+# if pydir not specified, install in site-packages via distutils setup()
 
 if pydir:
-    shutil.copy('../python/lammps.py', pydir)
+  if not os.path.isdir(pydir):
+    print "ERROR: pydir %s does not exist" % pydir
     sys.exit()
+  str = "cp ../python/lammps.py %s" % pydir
+  print str
+  outstr = commands.getoutput(str)
+  if len(outstr.strip()): print outstr
+  sys.exit()
+  
+print "installing lammps.py in Python site-packages dir"
 
-from distutils.core import setup
-
-os.chdir('../python')
+os.chdir('../python')                # in case invoked via make in src dir
 
+from distutils.core import setup
+sys.argv = ["setup.py","install"]    # as if had run "python setup.py install"
 setup(name = "lammps",
-    version = "15Aug12",
-    author = "Steve Plimpton",
-    author_email = "sjplimp@sandia.gov",
-    url = "http://lammps.sandia.gov",
-    description = """LAMMPS molecular dynamics library""",
-    py_modules = ["lammps"]
-)
+      version = "15Aug12",
+      author = "Steve Plimpton",
+      author_email = "sjplimp@sandia.gov",
+      url = "http://lammps.sandia.gov",
+      description = "LAMMPS molecular dynamics library",
+      py_modules = ["lammps"])