Use argparse.ArgumentParser for mklog.

2019-09-04  Martin Liska  <mliska@suse.cz>

	* mklog: Use argparse instead of getopt.

From-SVN: r275367

contrib/ChangeLog

+2019-09-04  Martin Liska  <mliska@suse.cz>
+
+	* mklog: Use argparse instead of getopt.
+
 2019-09-03  Ulrich Weigand  <uweigand@de.ibm.com>
 
 	* compare-all-tests (all_targets): Remove references to spu.

contrib/mklog

@@ -28,11 +28,11 @@
 #
 # Author: Yury Gribov <tetra2005@gmail.com>
 
+import argparse
 import sys
 import re
 import os.path
 import os
-import getopt
 import tempfile
 import time
 import shutil
@@ -66,21 +66,6 @@ class RegexCache(object):
 
 cache = RegexCache()
 
-def print_help_and_exit():
-    print("""\
-Usage: %s [-i | --inline] [PATCH]
-Generate ChangeLog template for PATCH.
-PATCH must be generated using diff(1)'s -up or -cp options
-(or their equivalent in Subversion/git).
-
-When PATCH is - or missing, read standard input.
-
-When -i is used, prepends ChangeLog to PATCH.
-If PATCH is not stdin, modifies PATCH in-place, otherwise writes
-to stdout.
-""" % me)
-    sys.exit(1)
-
 def run(cmd, die_on_error):
   """Simple wrapper for Popen."""
   proc = Popen(cmd.split(' '), stderr = PIPE, stdout = PIPE)
@@ -356,38 +341,30 @@ def parse_patch(contents):
 def main():
   name, email = read_user_info()
 
-  try:
-    opts, args = getopt.getopt(sys.argv[1:], 'hiv', ['help', 'verbose', 'inline'])
-  except getopt.GetoptError as err:
-    error(str(err))
-
-  inline = False
-  verbose = 0
-
-  for o, a in opts:
-    if o in ('-h', '--help'):
-      print_help_and_exit()
-    elif o in ('-i', '--inline'):
-      inline = True
-    elif o in ('-v', '--verbose'):
-      verbose += 1
-    else:
-      assert False, "unhandled option"
-
-  if len(args) == 0:
-    args = ['-']
+  help_message =  """\
+Generate ChangeLog template for PATCH.
+PATCH must be generated using diff(1)'s -up or -cp options
+(or their equivalent in Subversion/git).
+"""
 
-  if len(args) == 1 and args[0] == '-':
-    input = sys.stdin
-  elif len(args) == 1:
-    input = open(args[0])
-  else:
-    error("too many arguments; for more details run with -h")
+  inline_message = """\
+Prepends ChangeLog to PATCH.
+If PATCH is not stdin, modifies PATCH in-place,
+otherwise writes to stdout.'
+"""
 
+  parser = argparse.ArgumentParser(description = help_message)
+  parser.add_argument('-v', '--verbose', action = 'store_true', help = 'Verbose messages')
+  parser.add_argument('-i', '--inline', action = 'store_true', help = inline_message)
+  parser.add_argument('input', nargs = '?', help = 'Patch file (or missing, read standard input)')
+  args = parser.parse_args()
+  if args.input == '-':
+      args.input = None
+  input = open(args.input) if args.input else sys.stdin
   contents = input.read()
   diffs = parse_patch(contents)
 
-  if verbose:
+  if args.verbose:
     print("Parse results:")
     for d in diffs:
       d.dump()
@@ -431,7 +408,7 @@ def main():
 
     logs[log_name] += change_msg if change_msg else ":\n"
 
-  if inline and args[0] != '-':
+  if args.inline and args.input:
     # Get a temp filename, rather than an open filehandle, because we use
     # the open to truncate.
     fd, tmp = tempfile.mkstemp("tmp.XXXXXXXX")
@@ -439,7 +416,7 @@ def main():
 
     # Copy permissions to temp file
     # (old Pythons do not support shutil.copymode)
-    shutil.copymode(args[0], tmp)
+    shutil.copymode(args.input, tmp)
 
     # Open the temp file, clearing contents.
     out = open(tmp, 'w')
@@ -457,14 +434,14 @@ def main():
 
 %s\n""" % (log_name, date, name, email, msg))
 
-  if inline:
+  if args.inline:
     # Append patch body
     out.write(contents)
 
-    if args[0] != '-':
+    if args.input:
       # Write new contents atomically
       out.close()
-      shutil.move(tmp, args[0])
+      shutil.move(tmp, args.input)
 
 if __name__ == '__main__':
     main()