crude script that generates shebang fixing rules

diff --git a/check-shebang.py b/check-shebang.py
new file mode 100755 (executable)
index 0000000..9d0ad86
--- /dev/null
+++ b/check-shebang.py
@@ -0,0 +1,57 @@
+#!/usr/bin/python3
+
+import io
+import os
+import re
+import sys
+
+rep = {
+    'python2': [],
+    'python3': [],
+    'perl': [],
+}
+
+skip_files = [".h", ".c", ".cc", ".gif", ".png", ".jpg"]
+
+for root, dirs, files in os.walk(sys.argv[1]):
+    for name in files:
+        fname, fext = os.path.splitext(name)
+        if fext in skip_files:
+            continue
+
+        fpath = os.path.join(root, name)
+        with open(fpath, 'rt', encoding='utf-8', errors='replace') as f:
+            try:
+                fline = f.read(128)
+                f = io.StringIO(fline)
+                shebang = f.readline()
+            except UnicodeDecodeError as e:
+                print("%s: skipping file `%s': %s" % (sys.argv[0], fpath, e), file=sys.stderr)
+                continue
+            if re.compile(r'^#!/usr/bin/env python\s').match(shebang) \
+                    or re.compile(r'^#!/usr/bin/env python2\s').match(shebang) \
+                    or re.compile(r'^#!/usr/bin/python\s').match(shebang):
+                rep['python2'].append(fpath)
+            elif re.compile(r'^#!/usr/bin/env python3\s').match(shebang):
+                rep['python3'].append(fpath)
+            elif re.compile(r'^#!/usr/bin/env perl\s').match(shebang):
+                rep['perl'].append(fpath)
+
+def gf(files):
+    files.sort()
+    for i in range(0, len(files) - 1):
+        print("\t%s \\\n" % files[i], end='')
+    print("\t%s\n" % files[len(files) - 1])
+
+
+if rep['python2']:
+    print("sed -i -e '1s,#!/usr/bin/env python2,%{__python},' -e '1s,#!/usr/bin/env python,%{__python},' -e '1s,#!/usr/bin/python,%{__python},' \\")
+    gf(rep['python2'])
+
+if rep['python3']:
+    print("sed -i -e '1s,#!/usr/bin/env python3,%{__python3},' \\")
+    gf(rep['python3'])
+
+if rep['perl']:
+    print("sed -i -e '1s,#!/usr/bin/env perl,%{__perl},' \\")
+    gf(rep['perl'])