[pitivi: 17/65] Add a pre-hook commit to check the pep8 compliance of each commit

[Thibault Saunier <tsaunier src gnome org>]

commit 23bed12e31592b6a980459fc4555597587b47730
Author: Thibault Saunier <thibault saunier collabora com>
Date:   Wed Jun 22 23:42:23 2011 -0400

    Add a pre-hook commit to check the pep8 compliance of each commit

 autogen.sh      |    7 +++++++
 pre-commit.hook |   50 ++++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 57 insertions(+), 0 deletions(-)
---
diff --git a/autogen.sh b/autogen.sh
index 6270007..f0157a8 100755
--- a/autogen.sh
+++ b/autogen.sh
@@ -42,6 +42,13 @@ autoheader_check || DIE=1
 
 die_check $DIE
 
+# install pre-commit hook for doing clean commits
+if test ! \( -x .git/hooks/pre-commit -a -L .git/hooks/pre-commit \);
+then
+    rm -f .git/hooks/pre-commit
+    ln -s ../../pre-commit.hook .git/hooks/pre-commit
+fi
+
 # if no arguments specified then this will be printed
 if test -z "$*"; then
   echo "+ checking for autogen.sh options"
diff --git a/pre-commit.hook b/pre-commit.hook
new file mode 100755
index 0000000..238b322
--- /dev/null
+++ b/pre-commit.hook
@@ -0,0 +1,50 @@
+#!/usr/bin/env python
+from __future__ import with_statement
+import os
+import re
+import shutil
+import subprocess
+import sys
+import tempfile
+
+
+def system(*args, **kwargs):
+    kwargs.setdefault('stdout', subprocess.PIPE)
+    proc = subprocess.Popen(args, **kwargs)
+    out, err = proc.communicate()
+    return out
+
+
+def main():
+    modified = re.compile('^[AM]+\s+(?P<name>.*\.py)', re.MULTILINE)
+    files = system('git', 'status', '--porcelain')
+    files = modified.findall(files)
+
+    tempdir = tempfile.mkdtemp()
+    for name in files:
+        filename = os.path.join(tempdir, name)
+        filepath = os.path.dirname(filename)
+        if not os.path.exists(filepath):
+            os.makedirs(filepath)
+        with file(filename, 'w') as f:
+            system('git', 'show', ':' + name, stdout=f)
+    try:
+        output = system('pep8', '.', cwd=tempdir)
+    except OSError:
+        output =  "You should install the pep8 style checker to be able"\
+              " to commit in this repo.\nIt allow us to garantee that "\
+              "anything that is commited respects the pep8 coding style "\
+              "standard.\nYou can install it:\n"\
+              "  * on ubuntu, debian: $sudo apt-get install pep8 \n"\
+              "  * on fedora: #yum install python-pep8 \n"\
+              "  * Or add the official pep8 from http://www.python.org/dev/peps/pep-0008/"\
+              " in your $PATH"
+
+    shutil.rmtree(tempdir)
+    if output:
+        print output,
+        sys.exit(1)
+
+
+if __name__ == '__main__':
+    main()