new convenience utility: scripts/gendiff.py

scripts/gendiff.py

@@ -0,0 +1,44 @@
+#!/usr/bin/env python3
+
+"""
+Clean up control characters and trailing whitespace in the listed source files
+and create a unified diff between them.
+
+If more or less than two files are listed on the command line, the cleanup is
+performed on all files, but no diff is created.
+
+The source files are assumed to be terminal output captured by the `script`
+command.
+
+The original source files are backed up with the .orig extension.
+"""
+
+import sys,re
+from difflib import unified_diff
+
+fns = sys.argv[1:]
+
+translate = {
+	'\r': '[CR]\n',
+	'\b': '[BS]',
+}
+
+def cleanup_file(fn):
+	data = open(fn).read()
+	def gen_text():
+		for line in data.splitlines():
+			line = re.sub('\r\n','\n',line) # DOS CRLF to Unix LF
+			line = line.translate({ord(a):b for a,b in translate.items()})
+			line = re.sub(r'\s+$','',line)  # trailing whitespace
+			yield line
+	ret = list(gen_text())
+	open(fn+'.orig','w').write(data)
+	open(fn,'w').write('\n'.join(ret))
+	return ret
+
+cleaned_texts = [cleanup_file(fn) for fn in fns]
+
+if len(fns) == 2:
+	print('\n'.join(unified_diff(*cleaned_texts)))
+else:
+	print(f'{len(fns)} input files.  Not generating diff.')