diff --git a/dotdrop/comparator.py b/dotdrop/comparator.py
new file mode 100644
index 0000000..91d6429
--- /dev/null
+++ b/dotdrop/comparator.py
@@ -0,0 +1,90 @@
+"""
+author: deadc0de6 (https://github.com/deadc0de6)
+Copyright (c) 2017, deadc0de6
+
+handle the comparison of dotfiles and local deployment
+"""
+
+import os
+import shutil
+import filecmp
+
+# local imports
+from dotdrop.logger import Logger
+import dotdrop.utils as utils
+
+
+class Comparator:
+
+    def __init__(self, diffopts='', ignore=[], debug=False):
+        self.diffopts = diffopts
+        self.ignore = [os.path.expanduser(i) for i in ignore]
+        self.debug = debug
+        self.log = Logger()
+
+    def compare(self, left, right):
+        """diff left (dotdrop dotfile) and right (deployed file)"""
+        left = os.path.expanduser(left)
+        right = os.path.expanduser(right)
+        if not os.path.isdir(left):
+            return self._comp_file(left, right)
+        return self._comp_dir(left, right)
+
+    def _comp_file(self, left, right):
+        """compare a file"""
+        if left in self.ignore or right in self.ignore:
+            if self.debug:
+                self.log.dbg('ignoring diff {} and {}'.format(left, right))
+            return ''
+        return self._diff(left, right)
+
+    def _comp_dir(self, left, right):
+        """compare a directory"""
+        if left in self.ignore or right in self.ignore:
+            if self.debug:
+                self.log.dbg('ignoring diff {} and {}'.format(left, right))
+            return ''
+        if self.debug:
+            self.log.dbg('compare {} and {}'.format(left, right))
+        ret = []
+        comp = filecmp.dircmp(left, right, ignore=self.ignore)
+        # handle files only in deployed file
+        for i in comp.left_only:
+            if os.path.join(left, i) in self.ignore:
+                continue
+            ret.append('only in left: \"{}\"\n'.format(i))
+        for i in comp.right_only:
+            if os.path.join(right, i) in self.ignore:
+                continue
+            ret.append('only in right: \"{}\"\n'.format(i))
+
+        # same left and right but different type
+        funny = comp.common_funny
+        for i in funny:
+            lfile = os.path.join(left, i)
+            rfile = os.path.join(right, i)
+            short = os.path.basename(lfile)
+            # file vs dir
+            ret.append('different type: \"{}\"\n'.format(short))
+
+        # content is different
+        funny = comp.diff_files
+        funny.extend(comp.funny_files)
+        funny = list(set(funny))
+        for i in funny:
+            lfile = os.path.join(left, i)
+            rfile = os.path.join(right, i)
+            diff = self._diff(lfile, rfile, header=True)
+            ret.append(diff)
+
+        return ''.join(ret)
+
+    def _diff(self, left, right, header=False):
+        """diff using the unix tool diff"""
+        diff = utils.diff(left, right, raw=False,
+                          opts=self.diffopts, debug=self.debug)
+        if header:
+            lshort = os.path.basename(left)
+            rshort = os.path.basename(right)
+            diff = 'diff \"{}\":\n{}'.format(lshort, diff)
+        return diff
diff --git a/dotdrop/dotdrop.py b/dotdrop/dotdrop.py
index 10bccaa..b1af45f 100644
--- a/dotdrop/dotdrop.py
+++ b/dotdrop/dotdrop.py
@@ -16,6 +16,7 @@ from dotdrop.logger import Logger
 from dotdrop.templategen import Templategen
 from dotdrop.installer import Installer
 from dotdrop.updater import Updater
+from dotdrop.comparator import Comparator
 from dotdrop.dotfile import Dotfile
 from dotdrop.config import Cfg
 from dotdrop.utils import *
@@ -39,8 +40,9 @@ Usage:
   dotdrop install   [-fndVb] [-c <path>] [-p <profile>]
   dotdrop import    [-ldVb]  [-c <path>] [-p <profile>] <paths>...
   dotdrop compare   [-Vb]    [-c <path>] [-p <profile>]
-                             [-o <opts>] [--files=<files>]
-  dotdrop update    [-fdVb]  [-c <path>] [-p <profile>] <paths>...
+                             [-o <opts>] [-i <name>...]
+                             [--files=<files>]
+  dotdrop update    [-fdVb]  [-c <path>] <path>
   dotdrop listfiles [-Vb]    [-c <path>] [-p <profile>]
   dotdrop list      [-Vb]    [-c <path>]
   dotdrop --help
@@ -50,6 +52,7 @@ Options:
   -p --profile=<profile>  Specify the profile to use [default: {}].
   -c --cfg=<path>         Path to the config [default: config.yaml].
   --files=<files>         Comma separated list of files to compare.
+  -i --ignore=<name>      File name to ignore when diffing.
   -o --dopts=<opts>       Diff options [default: ].
   -n --nodiff             Do not diff when installing.
   -l --link               Import and link.
@@ -161,45 +164,57 @@ def _select(selections, dotfiles):
     return selected, ret
 
 
-def compare(opts, conf, tmp, focus=None):
+def compare(opts, conf, tmp, focus=None, ignore=[]):
     """compare dotfiles and return True if all identical"""
     dotfiles = conf.get_dotfiles(opts['profile'])
     if dotfiles == []:
         msg = 'no dotfiles defined for this profile (\"{}\")'
         LOG.err(msg.format(opts['profile']))
         return True
-    t = Templategen(base=opts['dotpath'], debug=opts['debug'])
-    inst = Installer(create=opts['create'], backup=opts['backup'],
-                     dry=opts['dry'], base=opts['dotpath'],
-                     debug=opts['debug'])
-
     # compare only specific files
-    ret = True
+    same = True
     selected = dotfiles
     if focus:
         selected, ret = _select(focus.replace(' ', '').split(','), dotfiles)
 
     if len(selected) < 1:
-        return ret
+        return False
+
+    t = Templategen(base=opts['dotpath'], debug=opts['debug'])
+    inst = Installer(create=opts['create'], backup=opts['backup'],
+                     dry=opts['dry'], base=opts['dotpath'],
+                     debug=opts['debug'])
+    comp = Comparator(diffopts=opts['dopts'], debug=opts['debug'],
+                      ignore=ignore)
 
     for dotfile in selected:
         if opts['debug']:
             LOG.dbg('comparing {}'.format(dotfile))
         src = dotfile.src
+        if not os.path.lexists(os.path.expanduser(dotfile.dst)):
+            LOG.emph('\"{}\" does not exist on local\n'.format(dotfile.dst))
+
         tmpsrc = None
         if dotfile.trans:
+            # apply transformation
             tmpsrc = apply_trans(opts, dotfile)
             if not tmpsrc:
+                # could not apply trans
                 continue
             src = tmpsrc
-            # create a fake dotfile which is the result of the transformation
-        same, diff = inst.compare(t, tmp, opts['profile'],
-                                  src, dotfile.dst, opts=opts['dopts'])
+        # install dotfile to temporary dir
+        ret, insttmp = inst.install_to_temp(t, tmp, opts['profile'],
+                                            src, dotfile.dst)
+        if not ret:
+            # failed to install to tmp
+            continue
+        diff = comp.compare(insttmp, dotfile.dst)
         if tmpsrc:
+            # clean tmp transformed dotfile if any
             tmpsrc = os.path.join(opts['dotpath'], tmpsrc)
             if os.path.exists(tmpsrc):
                 remove(tmpsrc)
-        if same:
+        if diff == '':
             if opts['debug']:
                 LOG.dbg('diffing \"{}\" VS \"{}\"'.format(dotfile.key,
                                                           dotfile.dst))
@@ -208,9 +223,9 @@ def compare(opts, conf, tmp, focus=None):
             LOG.log('diffing \"{}\" VS \"{}\"'.format(dotfile.key,
                                                       dotfile.dst))
             LOG.emph(diff)
-            ret = False
+            same = False
 
-    return ret
+    return same
 
 
 def update(opts, conf, paths):
@@ -345,7 +360,7 @@ def main():
             # compare local dotfiles with dotfiles stored in dotdrop
             tmp = get_tmpdir()
             opts['dopts'] = args['--dopts']
-            ret = compare(opts, conf, tmp, args['--files'])
+            ret = compare(opts, conf, tmp, args['--files'], args['--ignore'])
             if os.listdir(tmp):
                 LOG.raw('\ntemporary files available under {}'.format(tmp))
             else:
diff --git a/dotdrop/installer.py b/dotdrop/installer.py
index d95d8e2..0fa986b 100644
--- a/dotdrop/installer.py
+++ b/dotdrop/installer.py
@@ -9,6 +9,7 @@ import os
 
 # local imports
 from dotdrop.logger import Logger
+from dotdrop.comparator import Comparator
 import dotdrop.utils as utils
 
 
@@ -193,11 +194,12 @@ class Installer:
         tmpdst = os.path.join(tmpdir, sub)
         return self.install(templater, profile, src, tmpdst), tmpdst
 
-    def compare(self, templater, tmpdir, profile, src, dst, opts=''):
+    def install_to_temp(self, templater, tmpdir, profile, src, dst):
         """compare a temporary generated dotfile with the local one"""
+        ret = False
+        tmpdst = ''
         # saved some flags while comparing
         self.comparing = True
-        retval = False, ''
         drysaved = self.dry
         self.dry = False
         diffsaved = self.diff
@@ -208,26 +210,15 @@ class Installer:
         src = os.path.expanduser(src)
         dst = os.path.expanduser(dst)
         if self.debug:
-            self.log.dbg('comparing {} and {}'.format(src, dst))
-        if not os.path.lexists(dst):
-            # destination dotfile does not exist
-            retval = False, '\"{}\" does not exist on local\n'.format(dst)
-        else:
-            # install the dotfile to a temp directory for comparing
-            ret, tmpdst = self._install_to_temp(templater, profile,
-                                                src, dst, tmpdir)
-            if ret:
-                if self.debug:
-                    self.log.dbg('diffing {} and {}'.format(tmpdst, dst))
-                diff = utils.diff(tmpdst, dst, raw=False,
-                                  opts=opts, debug=self.debug)
-                if diff == '':
-                    retval = True, ''
-                else:
-                    retval = False, diff
+            self.log.dbg('tmp install {} to {}'.format(src, dst))
+        # install the dotfile to a temp directory for comparing
+        ret, tmpdst = self._install_to_temp(templater, profile,
+                                            src, dst, tmpdir)
+        if self.debug:
+            self.log.dbg('tmp installed in {}'.format(tmpdst))
         # reset flags
         self.dry = drysaved
         self.diff = diffsaved
         self.comparing = False
         self.create = createsaved
-        return retval
+        return ret, tmpdst
diff --git a/tests-ng/compare-ignore.sh b/tests-ng/compare-ignore.sh
new file mode 100755
index 0000000..1141c82
--- /dev/null
+++ b/tests-ng/compare-ignore.sh
@@ -0,0 +1,100 @@
+#!/usr/bin/env bash
+# author: deadc0de6 (https://github.com/deadc0de6)
+# Copyright (c) 2017, deadc0de6
+#
+# test updates
+# returns 1 in case of error
+#
+
+# exit on first error
+#set -e
+
+# all this crap to get current path
+rl="readlink -f"
+if ! ${rl} "${0}" >/dev/null 2>&1; then
+  rl="realpath"
+
+  if ! hash ${rl}; then
+    echo "\"${rl}\" not found !" && exit 1
+  fi
+fi
+cur=$(dirname "$(${rl} "${0}")")
+
+#hash dotdrop >/dev/null 2>&1
+#[ "$?" != "0" ] && echo "install dotdrop to run tests" && exit 1
+
+#echo "called with ${1}"
+
+# dotdrop path can be pass as argument
+ddpath="${cur}/../"
+[ "${1}" != "" ] && ddpath="${1}"
+[ ! -d ${ddpath} ] && echo "ddpath \"${ddpath}\" is not a directory" && exit 1
+
+export PYTHONPATH="${ddpath}:${PYTHONPATH}"
+bin="python3 -m dotdrop.dotdrop"
+
+echo "dotdrop path: ${ddpath}"
+echo "pythonpath: ${PYTHONPATH}"
+
+# get the helpers
+source ${cur}/helpers
+
+echo "RUNNING $(basename $BASH_SOURCE)"
+
+################################################################
+# this is the test
+################################################################
+
+# dotdrop directory
+basedir=`mktemp -d`
+echo "[+] dotdrop dir: ${basedir}"
+echo "[+] dotpath dir: ${basedir}/dotfiles"
+
+# the dotfile to be imported
+tmpd=`mktemp -d`
+
+# some files
+mkdir -p ${tmpd}/{program,config}
+touch ${tmpd}/program/a
+touch ${tmpd}/config/a
+
+# create the config file
+cfg="${basedir}/config.yaml"
+create_conf ${cfg} # sets token
+
+# import
+echo "[+] import"
+cd ${ddpath} | ${bin} import -c ${cfg} ${tmpd}/program
+cd ${ddpath} | ${bin} import -c ${cfg} ${tmpd}/config
+
+# add files
+echo "[+] add files"
+touch ${tmpd}/program/b
+touch ${tmpd}/config/b
+
+# expects diff
+echo "[+] comparing normal"
+set +e
+cd ${ddpath} | ${bin} compare -c ${cfg} --verbose
+[ "$?" = "0" ] && exit 1
+set -e
+
+# expects one diff
+echo "[+] comparing with ignore"
+set +e
+cd ${ddpath} | ${bin} compare -c ${cfg} --verbose --ignore=${tmpd}/config/b
+[ "$?" = "0" ] && exit 1
+set -e
+
+# expects no diff
+echo "[+] comparing with ignore pattern"
+set +e
+cd ${ddpath} | ${bin} compare -c ${cfg} --verbose --ignore=b
+[ "$?" != "0" ] && exit 1
+set -e
+
+## CLEANING
+rm -rf ${basedir} ${tmpd}
+
+echo "OK"
+exit 0
diff --git a/tests-ng/compare.sh b/tests-ng/compare.sh
new file mode 100755
index 0000000..86b4a85
--- /dev/null
+++ b/tests-ng/compare.sh
@@ -0,0 +1,120 @@
+#!/usr/bin/env bash
+# author: deadc0de6 (https://github.com/deadc0de6)
+# Copyright (c) 2017, deadc0de6
+#
+# test updates
+# returns 1 in case of error
+#
+
+# exit on first error
+set -e
+
+# all this crap to get current path
+rl="readlink -f"
+if ! ${rl} "${0}" >/dev/null 2>&1; then
+  rl="realpath"
+
+  if ! hash ${rl}; then
+    echo "\"${rl}\" not found !" && exit 1
+  fi
+fi
+cur=$(dirname "$(${rl} "${0}")")
+
+#hash dotdrop >/dev/null 2>&1
+#[ "$?" != "0" ] && echo "install dotdrop to run tests" && exit 1
+
+#echo "called with ${1}"
+
+# dotdrop path can be pass as argument
+ddpath="${cur}/../"
+[ "${1}" != "" ] && ddpath="${1}"
+[ ! -d ${ddpath} ] && echo "ddpath \"${ddpath}\" is not a directory" && exit 1
+
+export PYTHONPATH="${ddpath}:${PYTHONPATH}"
+bin="python3 -m dotdrop.dotdrop"
+
+echo "dotdrop path: ${ddpath}"
+echo "pythonpath: ${PYTHONPATH}"
+
+# get the helpers
+source ${cur}/helpers
+
+echo "RUNNING $(basename $BASH_SOURCE)"
+
+################################################################
+# this is the test
+################################################################
+
+# dotdrop directory
+basedir=`mktemp -d`
+echo "[+] dotdrop dir: ${basedir}"
+echo "[+] dotpath dir: ${basedir}/dotfiles"
+
+# the dotfile to be imported
+tmpd=`mktemp -d`
+
+# single file
+echo 'unique' > ${tmpd}/uniquefile
+
+# hierarchy from https://pymotw.com/2/filecmp/
+# create the hierarchy
+# for dir1 (originally imported directory))))
+mkdir ${tmpd}/dir1
+touch ${tmpd}/dir1/file_only_in_dir1
+mkdir -p ${tmpd}/dir1/dir_only_in_dir1
+mkdir -p ${tmpd}/dir1/common_dir
+echo 'this file is the same' > ${tmpd}/dir1/common_file
+echo 'in dir1' > ${tmpd}/dir1/not_the_same
+echo 'This is a file in dir1' > ${tmpd}/dir1/file_in_dir1
+mkdir -p ${tmpd}/dir1/sub/sub2
+mkdir -p ${tmpd}/dir1/notindir2/notindir2
+echo 'first' > ${tmpd}/dir1/sub/sub2/different
+#tree ${tmpd}/dir1
+
+# create the hierarchy
+# for dir2 (modified original for update)
+mkdir ${tmpd}/dir2
+touch ${tmpd}/dir2/file_only_in_dir2
+mkdir -p ${tmpd}/dir2/dir_only_in_dir2
+mkdir -p ${tmpd}/dir2/common_dir
+echo 'this file is the same' > ${tmpd}/dir2/common_file
+echo 'in dir2' > ${tmpd}/dir2/not_the_same
+mkdir -p ${tmpd}/dir2/file_in_dir1
+mkdir -p ${tmpd}/dir2/sub/sub2
+echo 'modified' > ${tmpd}/dir2/sub/sub2/different
+mkdir -p ${tmpd}/dir2/new/new2
+#tree ${tmpd}/dir2
+
+# create the config file
+cfg="${basedir}/config.yaml"
+create_conf ${cfg} # sets token
+
+# import dir1
+echo "[+] import"
+cd ${ddpath} | ${bin} import -c ${cfg} ${tmpd}/dir1
+cd ${ddpath} | ${bin} import -c ${cfg} ${tmpd}/uniquefile
+
+# let's see the dotpath
+#tree ${basedir}/dotfiles
+
+# change dir1 to dir2 in deployed
+echo "[+] change dir"
+rm -rf ${tmpd}/dir1
+mv ${tmpd}/dir2 ${tmpd}/dir1
+#tree ${tmpd}/dir1
+
+# change unique file
+echo 'changed' > ${tmpd}/uniquefile
+
+# compare
+echo "[+] comparing"
+set +e
+cd ${ddpath} | ${bin} compare -c ${cfg} --verbose
+[ "$?" = "0" ] && exit 1
+set -e
+
+## CLEANING
+rm -rf ${basedir} ${tmpd}
+
+echo "OK"
+exit 0
diff --git a/tests/test_compare.py b/tests/test_compare.py
index efa2f99..41ae303 100644
--- a/tests/test_compare.py
+++ b/tests/test_compare.py
@@ -14,6 +14,7 @@ from dotdrop.dotdrop import importer
 from dotdrop.dotdrop import compare
 from dotdrop.dotfile import Dotfile
 from dotdrop.installer import Installer
+from dotdrop.comparator import Comparator
 from dotdrop.templategen import Templategen
 
 from tests.helpers import *
@@ -32,12 +33,20 @@ class TestCompare(unittest.TestCase):
         t = Templategen(base=opts['dotpath'], debug=True)
         inst = Installer(create=opts['create'], backup=opts['backup'],
                          dry=opts['dry'], base=opts['dotpath'], debug=True)
+        comp = Comparator()
         results = {}
         for dotfile in dotfiles:
-            same, _ = inst.compare(t, tmp, opts['profile'],
-                                   dotfile.src, dotfile.dst)
+            ret, insttmp = inst.install_to_temp(t, tmp, opts['profile'],
+                                                dotfile.src, dotfile.dst)
+            if not ret:
+                results[path] = False
+                continue
+            diff = comp.compare(insttmp, dotfile.dst)
+            print('XXXX diff for {} and {}:\n{}'.format(dotfile.src,
+                                                        dotfile.dst,
+                                                        diff))
             path = os.path.expanduser(dotfile.dst)
-            results[path] = same
+            results[path] = diff == ''
         return results
 
     def edit_content(self, path, newcontent, binary=False):