[devtools] script support for managing source file copyright headers

Three subcommands to this script:

1) ./copyright_header.py report

Examines git-tracked files with extensions that match:

INCLUDE = ['*.h', '*.cpp', '*.cc', '*.c', '*.py']

Helps to:

-> Identify source files without copyright
-> Identify source files added with something other than "The Bitcoin Core
developers" holder so we can be sure it is appropriate
-> Identify unintentional typos in the copyright line

2) ./copyright_header.py update

Replaces fix-copyright-headers.py. It does file editing in native python
rather than subprocessing out to perl as was the case with
fix-copyright-headers.py. It also shares code with the 'report' functions.

3) ./copyright_header.py insert

Inserts a copyright header into a source file with the proper format and
dates.

3 files changed, 662 insertions, 76 deletions

diff --git a/contrib/devtools/README.md b/contrib/devtools/README.md
index af5c000b03..b13dc6d3f0 100644
--- a/contrib/devtools/README.md
+++ b/contrib/devtools/README.md
@@ -24,21 +24,64 @@ the script should be called from the git root folder as follows.
 ```
 git diff -U0 HEAD~1.. | ./contrib/devtools/clang-format-diff.py -p1 -i -v
 ```
+copyright\_header.py
+====================
 
-fix-copyright-headers.py
-========================
+Provides utilities for managing copyright headers of `The Bitcoin Core
+developers` in repository source files. It has three subcommands:
 
-Every year newly updated files need to have its copyright headers updated to reflect the current year.
-If you run this script from the root folder it will automatically update the year on the copyright header for all
-source files if these have a git commit from the current year.
+```
+$ ./copyright_header.py report <base_directory> [verbose]
+$ ./copyright_header.py update <base_directory>
+$ ./copyright_header.py insert <file>
+```
+Running these subcommands without arguments displays a usage string.
 
-For example a file changed in 2015 (with 2015 being the current year):
+copyright\_header.py report \<base\_directory\> [verbose]
+---------------------------------------------------------
 
-```// Copyright (c) 2009-2013 The Bitcoin Core developers```
+Produces a report of all copyright header notices found inside the source files
+of a repository. Useful to quickly visualize the state of the headers.
+Specifying `verbose` will list the full filenames of files of each category.
 
-would be changed to:
+copyright\_header.py update \<base\_directory\> [verbose]
+---------------------------------------------------------
+Updates all the copyright headers of `The Bitcoin Core developers` which were
+changed in a year more recent than is listed. For example:
+```
+// Copyright (c) <firstYear>-<lastYear> The Bitcoin Core developers
+```
+will be updated to:
+```
+// Copyright (c) <firstYear>-<lastModifiedYear> The Bitcoin Core developers
+```
+where `<lastModifiedYear>` is obtained from the `git log` history.
 
-```// Copyright (c) 2009-2015 The Bitcoin Core developers```
+This subcommand also handles copyright headers that have only a single year. In
+those cases:
+```
+// Copyright (c) <year> The Bitcoin Core developers
+```
+will be updated to:
+```
+// Copyright (c) <year>-<lastModifiedYear> The Bitcoin Core developers
+```
+where the update is appropriate.
+
+copyright\_header.py insert \<file\>
+------------------------------------
+Inserts a copyright header for `The Bitcoin Core developers` at the top of the
+file in either Python or C++ style as determined by the file extension. If the
+file is a Python file and it has  `#!` starting the first line, the header is
+inserted in the line below it.
+
+The copyright dates will be set to be `<year_introduced>-<current_year>` where
+`<year_introduced>` is according to the `git log` history. If
+`<year_introduced>` is equal to `<current_year>`, it will be set as a single
+year rather than two hyphenated years.
+
+If the file already has a copyright for `The Bitcoin Core developers`, the
+script will exit.
 
 git-subtree-check.sh
 ====================
diff --git a/contrib/devtools/copyright_header.py b/contrib/devtools/copyright_header.py
new file mode 100755
index 0000000000..9f35c378bf
--- /dev/null
+++ b/contrib/devtools/copyright_header.py
@@ -0,0 +1,610 @@
+#!/usr/bin/env python3
+# Copyright (c) 2016 The Bitcoin Core developers
+# Distributed under the MIT software license, see the accompanying
+# file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+import re
+import fnmatch
+import sys
+import subprocess
+import datetime
+import os
+
+################################################################################
+# file filtering
+################################################################################
+
+EXCLUDE = [
+    # libsecp256k1:
+    'src/secp256k1/include/secp256k1.h',
+    'src/secp256k1/include/secp256k1_ecdh.h',
+    'src/secp256k1/include/secp256k1_recovery.h',
+    'src/secp256k1/include/secp256k1_schnorr.h',
+    'src/secp256k1/src/java/org_bitcoin_NativeSecp256k1.c',
+    'src/secp256k1/src/java/org_bitcoin_NativeSecp256k1.h',
+    'src/secp256k1/src/java/org_bitcoin_Secp256k1Context.c',
+    'src/secp256k1/src/java/org_bitcoin_Secp256k1Context.h',
+    # auto generated:
+    'src/univalue/lib/univalue_escapes.h',
+    'src/qt/bitcoinstrings.cpp',
+    'src/chainparamsseeds.h',
+    # other external copyrights:
+    'src/tinyformat.h',
+    'src/leveldb/util/env_win.cc',
+    'src/crypto/ctaes/bench.c',
+    'qa/rpc-tests/test_framework/bignum.py',
+    # python init:
+    '*__init__.py',
+]
+EXCLUDE_COMPILED = re.compile('|'.join([fnmatch.translate(m) for m in EXCLUDE]))
+
+INCLUDE = ['*.h', '*.cpp', '*.cc', '*.c', '*.py']
+INCLUDE_COMPILED = re.compile('|'.join([fnmatch.translate(m) for m in INCLUDE]))
+
+def applies_to_file(filename):
+    return ((EXCLUDE_COMPILED.match(filename) is None) and
+            (INCLUDE_COMPILED.match(filename) is not None))
+
+################################################################################
+# obtain list of files in repo according to INCLUDE and EXCLUDE
+################################################################################
+
+GIT_LS_CMD = 'git ls-files'
+
+def call_git_ls():
+    out = subprocess.check_output(GIT_LS_CMD.split(' '))
+    return [f for f in out.decode("utf-8").split('\n') if f != '']
+
+def get_filenames_to_examine():
+    filenames = call_git_ls()
+    return sorted([filename for filename in filenames if
+                   applies_to_file(filename)])
+
+################################################################################
+# define and compile regexes for the patterns we are looking for
+################################################################################
+
+
+COPYRIGHT_WITH_C = 'Copyright \(c\)'
+COPYRIGHT_WITHOUT_C = 'Copyright'
+ANY_COPYRIGHT_STYLE = '(%s|%s)' % (COPYRIGHT_WITH_C, COPYRIGHT_WITHOUT_C)
+
+YEAR = "20[0-9][0-9]"
+YEAR_RANGE = '(%s)(-%s)?' % (YEAR, YEAR)
+YEAR_LIST = '(%s)(, %s)+' % (YEAR, YEAR)
+ANY_YEAR_STYLE = '(%s|%s)' % (YEAR_RANGE, YEAR_LIST)
+ANY_COPYRIGHT_STYLE_OR_YEAR_STYLE = ("%s %s" % (ANY_COPYRIGHT_STYLE,
+                                                ANY_YEAR_STYLE))
+
+ANY_COPYRIGHT_COMPILED = re.compile(ANY_COPYRIGHT_STYLE_OR_YEAR_STYLE)
+
+def compile_copyright_regex(copyright_style, year_style, name):
+    return re.compile('%s %s %s' % (copyright_style, year_style, name))
+
+EXPECTED_HOLDER_NAMES = [
+    "Satoshi Nakamoto\n",
+    "The Bitcoin Core developers\n",
+    "The Bitcoin Core developers \n",
+    "Bitcoin Core Developers\n",
+    "the Bitcoin Core developers\n",
+    "The Bitcoin developers\n",
+    "The LevelDB Authors\. All rights reserved\.\n",
+    "BitPay Inc\.\n",
+    "BitPay, Inc\.\n",
+    "University of Illinois at Urbana-Champaign\.\n",
+    "MarcoFalke\n",
+    "Pieter Wuille\n",
+    "Pieter Wuille +\*\n",
+    "Pieter Wuille, Gregory Maxwell +\*\n",
+    "Pieter Wuille, Andrew Poelstra +\*\n",
+    "Andrew Poelstra +\*\n",
+    "Wladimir J. van der Laan\n",
+    "Jeff Garzik\n",
+    "Diederik Huys, Pieter Wuille +\*\n",
+    "Thomas Daede, Cory Fields +\*\n",
+    "Jan-Klaas Kollhof\n",
+    "Sam Rushing\n",
+    "ArtForz -- public domain half-a-node\n",
+]
+
+DOMINANT_STYLE_COMPILED = {}
+YEAR_LIST_STYLE_COMPILED = {}
+WITHOUT_C_STYLE_COMPILED = {}
+
+for holder_name in EXPECTED_HOLDER_NAMES:
+    DOMINANT_STYLE_COMPILED[holder_name] = (
+        compile_copyright_regex(COPYRIGHT_WITH_C, YEAR_RANGE, holder_name))
+    YEAR_LIST_STYLE_COMPILED[holder_name] = (
+        compile_copyright_regex(COPYRIGHT_WITH_C, YEAR_LIST, holder_name))
+    WITHOUT_C_STYLE_COMPILED[holder_name] = (
+        compile_copyright_regex(COPYRIGHT_WITHOUT_C, ANY_YEAR_STYLE,
+                                holder_name))
+
+################################################################################
+# search file contents for copyright message of particular category
+################################################################################
+
+def get_count_of_copyrights_of_any_style_any_holder(contents):
+    return len(ANY_COPYRIGHT_COMPILED.findall(contents))
+
+def file_has_dominant_style_copyright_for_holder(contents, holder_name):
+    match = DOMINANT_STYLE_COMPILED[holder_name].search(contents)
+    return match is not None
+
+def file_has_year_list_style_copyright_for_holder(contents, holder_name):
+    match = YEAR_LIST_STYLE_COMPILED[holder_name].search(contents)
+    return match is not None
+
+def file_has_without_c_style_copyright_for_holder(contents, holder_name):
+    match = WITHOUT_C_STYLE_COMPILED[holder_name].search(contents)
+    return match is not None
+
+################################################################################
+# get file info
+################################################################################
+
+def read_file(filename):
+    return open(os.path.abspath(filename), 'r').read()
+
+def gather_file_info(filename):
+    info = {}
+    info['filename'] = filename
+    c = read_file(filename)
+    info['contents'] = c
+
+    info['all_copyrights'] = get_count_of_copyrights_of_any_style_any_holder(c)
+
+    info['classified_copyrights'] = 0
+    info['dominant_style'] = {}
+    info['year_list_style'] = {}
+    info['without_c_style'] = {}
+    for holder_name in EXPECTED_HOLDER_NAMES:
+        has_dominant_style = (
+            file_has_dominant_style_copyright_for_holder(c, holder_name))
+        has_year_list_style = (
+            file_has_year_list_style_copyright_for_holder(c, holder_name))
+        has_without_c_style = (
+            file_has_without_c_style_copyright_for_holder(c, holder_name))
+        info['dominant_style'][holder_name] = has_dominant_style
+        info['year_list_style'][holder_name] = has_year_list_style
+        info['without_c_style'][holder_name] = has_without_c_style
+        if has_dominant_style or has_year_list_style or has_without_c_style:
+            info['classified_copyrights'] = info['classified_copyrights'] + 1
+    return info
+
+################################################################################
+# report execution
+################################################################################
+
+SEPARATOR = '-'.join(['' for _ in range(80)])
+
+def print_filenames(filenames, verbose):
+    if not verbose:
+        return
+    for filename in filenames:
+        print("\t%s" % filename)
+
+def print_report(file_infos, verbose):
+    print(SEPARATOR)
+    examined = [i['filename'] for i in file_infos]
+    print("%d files examined according to INCLUDE and EXCLUDE fnmatch rules" %
+          len(examined))
+    print_filenames(examined, verbose)
+
+    print(SEPARATOR)
+    print('')
+    zero_copyrights = [i['filename'] for i in file_infos if
+                       i['all_copyrights'] == 0]
+    print("%4d with zero copyrights" % len(zero_copyrights))
+    print_filenames(zero_copyrights, verbose)
+    one_copyright = [i['filename'] for i in file_infos if
+                     i['all_copyrights'] == 1]
+    print("%4d with one copyright" % len(one_copyright))
+    print_filenames(one_copyright, verbose)
+    two_copyrights = [i['filename'] for i in file_infos if
+                      i['all_copyrights'] == 2]
+    print("%4d with two copyrights" % len(two_copyrights))
+    print_filenames(two_copyrights, verbose)
+    three_copyrights = [i['filename'] for i in file_infos if
+                        i['all_copyrights'] == 3]
+    print("%4d with three copyrights" % len(three_copyrights))
+    print_filenames(three_copyrights, verbose)
+    four_or_more_copyrights = [i['filename'] for i in file_infos if
+                               i['all_copyrights'] >= 4]
+    print("%4d with four or more copyrights" % len(four_or_more_copyrights))
+    print_filenames(four_or_more_copyrights, verbose)
+    print('')
+    print(SEPARATOR)
+    print('Copyrights with dominant style:\ne.g. "Copyright (c)" and '
+          '"<year>" or "<startYear>-<endYear>":\n')
+    for holder_name in EXPECTED_HOLDER_NAMES:
+        dominant_style = [i['filename'] for i in file_infos if
+                          i['dominant_style'][holder_name]]
+        if len(dominant_style) > 0:
+            print("%4d with '%s'" % (len(dominant_style),
+                                     holder_name.replace('\n', '\\n')))
+            print_filenames(dominant_style, verbose)
+    print('')
+    print(SEPARATOR)
+    print('Copyrights with year list style:\ne.g. "Copyright (c)" and '
+          '"<year1>, <year2>, ...":\n')
+    for holder_name in EXPECTED_HOLDER_NAMES:
+        year_list_style = [i['filename'] for i in file_infos if
+                           i['year_list_style'][holder_name]]
+        if len(year_list_style) > 0:
+            print("%4d with '%s'" % (len(year_list_style),
+                                     holder_name.replace('\n', '\\n')))
+            print_filenames(year_list_style, verbose)
+    print('')
+    print(SEPARATOR)
+    print('Copyrights with no "(c)" style:\ne.g. "Copyright" and "<year>" or '
+          '"<startYear>-<endYear>":\n')
+    for holder_name in EXPECTED_HOLDER_NAMES:
+        without_c_style = [i['filename'] for i in file_infos if
+                           i['without_c_style'][holder_name]]
+        if len(without_c_style) > 0:
+            print("%4d with '%s'" % (len(without_c_style),
+                                     holder_name.replace('\n', '\\n')))
+            print_filenames(without_c_style, verbose)
+
+    print('')
+    print(SEPARATOR)
+
+    unclassified_copyrights = [i['filename'] for i in file_infos if
+                               i['classified_copyrights'] < i['all_copyrights']]
+    print("%d with unexpected copyright holder names" %
+          len(unclassified_copyrights))
+    print_filenames(unclassified_copyrights, verbose)
+    print(SEPARATOR)
+
+def exec_report(base_directory, verbose):
+    original_cwd = os.getcwd()
+    os.chdir(base_directory)
+    filenames = get_filenames_to_examine()
+    file_infos = [gather_file_info(f) for f in filenames]
+    print_report(file_infos, verbose)
+    os.chdir(original_cwd)
+
+################################################################################
+# report cmd
+################################################################################
+
+REPORT_USAGE = """
+Produces a report of all copyright header notices found inside the source files
+of a repository.
+
+Usage:
+    $ ./copyright_header.py report <base_directory> [verbose]
+
+Arguments:
+    <base_directory> - The base directory of a bitcoin source code repository.
+    [verbose] - Includes a list of every file of each subcategory in the report.
+"""
+
+def report_cmd(argv):
+    if len(argv) == 2:
+        sys.exit(REPORT_USAGE)
+        
+    base_directory = argv[2]
+    if not os.path.exists(base_directory):
+        sys.exit("*** bad <base_directory>: %s" % base_directory)
+
+    if len(argv) == 3:
+        verbose = False
+    elif argv[3] == 'verbose':
+        verbose = True
+    else:
+        sys.exit("*** unknown argument: %s" % argv[2])
+
+    exec_report(base_directory, verbose)
+
+################################################################################
+# query git for year of last change
+################################################################################
+
+GIT_LOG_CMD = "git log --pretty=format:%%ai %s"
+
+def call_git_log(filename):
+    out = subprocess.check_output((GIT_LOG_CMD % filename).split(' '))
+    return out.decode("utf-8").split('\n')
+
+def get_git_change_years(filename):
+    git_log_lines = call_git_log(filename)
+    if len(git_log_lines) == 0:
+        return [datetime.date.today().year]
+    # timestamp is in ISO 8601 format. e.g. "2016-09-05 14:25:32 -0600"
+    return [line.split(' ')[0].split('-')[0] for line in git_log_lines]
+
+def get_most_recent_git_change_year(filename):
+    return max(get_git_change_years(filename))
+
+################################################################################
+# read and write to file
+################################################################################
+
+def read_file_lines(filename):
+    f = open(os.path.abspath(filename), 'r')
+    file_lines = f.readlines()
+    f.close()
+    return file_lines
+
+def write_file_lines(filename, file_lines):
+    f = open(os.path.abspath(filename), 'w')
+    f.write(''.join(file_lines))
+    f.close()
+
+################################################################################
+# update header years execution
+################################################################################
+
+COPYRIGHT = 'Copyright \(c\)'
+YEAR = "20[0-9][0-9]"
+YEAR_RANGE = '(%s)(-%s)?' % (YEAR, YEAR)
+HOLDER = 'The Bitcoin Core developers'
+UPDATEABLE_LINE_COMPILED = re.compile(' '.join([COPYRIGHT, YEAR_RANGE, HOLDER]))
+
+def get_updatable_copyright_line(file_lines):
+    index = 0
+    for line in file_lines:
+        if UPDATEABLE_LINE_COMPILED.search(line) is not None:
+            return index, line
+        index = index + 1
+    return None, None
+
+def parse_year_range(year_range):
+    year_split = year_range.split('-')
+    start_year = year_split[0]
+    if len(year_split) == 1:
+        return start_year, start_year
+    return start_year, year_split[1]
+
+def year_range_to_str(start_year, end_year):
+    if start_year == end_year:
+        return start_year
+    return "%s-%s" % (start_year, end_year)
+
+def create_updated_copyright_line(line, last_git_change_year):
+    copyright_splitter = 'Copyright (c) '
+    copyright_split = line.split(copyright_splitter)
+    # Preserve characters on line that are ahead of the start of the copyright
+    # notice - they are part of the comment block and vary from file-to-file.
+    before_copyright = copyright_split[0]
+    after_copyright = copyright_split[1]
+
+    space_split = after_copyright.split(' ')
+    year_range = space_split[0]
+    start_year, end_year = parse_year_range(year_range)
+    if end_year == last_git_change_year:
+        return line
+    return (before_copyright + copyright_splitter +
+            year_range_to_str(start_year, last_git_change_year) + ' ' +
+            ' '.join(space_split[1:]))
+
+def update_updatable_copyright(filename):
+    file_lines = read_file_lines(filename)
+    index, line = get_updatable_copyright_line(file_lines)
+    if not line:
+        print_file_action_message(filename, "No updatable copyright.")
+        return
+    last_git_change_year = get_most_recent_git_change_year(filename)
+    new_line = create_updated_copyright_line(line, last_git_change_year)
+    if line == new_line:
+        print_file_action_message(filename, "Copyright up-to-date.")
+        return
+    file_lines[index] = new_line
+    write_file_lines(filename, file_lines)
+    print_file_action_message(filename,
+                              "Copyright updated! -> %s" % last_git_change_year)
+
+def exec_update_header_year(base_directory):
+    original_cwd = os.getcwd()
+    os.chdir(base_directory)
+    for filename in get_filenames_to_examine():
+        update_updatable_copyright(filename)
+    os.chdir(original_cwd)
+
+################################################################################
+# update cmd
+################################################################################
+
+UPDATE_USAGE = """
+Updates all the copyright headers of "The Bitcoin Core developers" which were
+changed in a year more recent than is listed. For example:
+
+// Copyright (c) <firstYear>-<lastYear> The Bitcoin Core developers
+
+will be updated to:
+
+// Copyright (c) <firstYear>-<lastModifiedYear> The Bitcoin Core developers
+
+where <lastModifiedYear> is obtained from the 'git log' history.
+
+This subcommand also handles copyright headers that have only a single year. In those cases:
+
+// Copyright (c) <year> The Bitcoin Core developers
+
+will be updated to:
+
+// Copyright (c) <year>-<lastModifiedYear> The Bitcoin Core developers
+
+where the update is appropriate.
+
+Usage:
+    $ ./copyright_header.py update <base_directory>
+
+Arguments:
+    <base_directory> - The base directory of a bitcoin source code repository.
+"""
+
+def print_file_action_message(filename, action):
+    print("%-52s %s" % (filename, action))
+
+def update_cmd(argv):
+    if len(argv) != 3:
+        sys.exit(UPDATE_USAGE)
+    
+    base_directory = argv[2]
+    if not os.path.exists(base_directory):
+        sys.exit("*** bad base_directory: %s" % base_directory)
+    exec_update_header_year(base_directory)
+
+################################################################################
+# inserted copyright header format
+################################################################################
+
+def get_header_lines(header, start_year, end_year):
+    lines = header.split('\n')[1:-1]
+    lines[0] = lines[0] % year_range_to_str(start_year, end_year)
+    return [line + '\n' for line in lines]
+
+CPP_HEADER = '''
+// Copyright (c) %s The Bitcoin Core developers
+// Distributed under the MIT software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+'''
+
+def get_cpp_header_lines_to_insert(start_year, end_year):
+    return reversed(get_header_lines(CPP_HEADER, start_year, end_year))
+
+PYTHON_HEADER = '''
+# Copyright (c) %s The Bitcoin Core developers
+# Distributed under the MIT software license, see the accompanying
+# file COPYING or http://www.opensource.org/licenses/mit-license.php.
+'''
+
+def get_python_header_lines_to_insert(start_year, end_year):
+    return reversed(get_header_lines(PYTHON_HEADER, start_year, end_year))
+
+################################################################################
+# query git for year of last change
+################################################################################
+
+def get_git_change_year_range(filename):
+    years = get_git_change_years(filename)
+    return min(years), max(years)
+
+################################################################################
+# check for existing core copyright
+################################################################################
+
+def file_already_has_core_copyright(file_lines):
+    index, _ = get_updatable_copyright_line(file_lines)
+    return index != None
+
+################################################################################
+# insert header execution
+################################################################################
+
+def file_has_hashbang(file_lines):
+    if len(file_lines) < 1:
+        return False
+    if len(file_lines[0]) <= 2:
+        return False
+    return file_lines[0][:2] == '#!'
+
+def insert_python_header(filename, file_lines, start_year, end_year):
+    if file_has_hashbang(file_lines):
+        insert_idx = 1 
+    else:
+        insert_idx = 0
+    header_lines = get_python_header_lines_to_insert(start_year, end_year)
+    for line in header_lines:
+        file_lines.insert(insert_idx, line)
+    write_file_lines(filename, file_lines)
+
+def insert_cpp_header(filename, file_lines, start_year, end_year):
+    header_lines = get_cpp_header_lines_to_insert(start_year, end_year)
+    for line in header_lines:
+        file_lines.insert(0, line)
+    write_file_lines(filename, file_lines)
+
+def exec_insert_header(filename, style):
+    file_lines = read_file_lines(filename)
+    if file_already_has_core_copyright(file_lines):
+        sys.exit('*** %s already has a copyright by The Bitcoin Core developers'
+                 % (filename))
+    start_year, end_year = get_git_change_year_range(filename)
+    if style == 'python':
+        insert_python_header(filename, file_lines, start_year, end_year)
+    else:
+        insert_cpp_header(filename, file_lines, start_year, end_year)
+
+################################################################################
+# insert cmd
+################################################################################
+
+INSERT_USAGE = """
+Inserts a copyright header for "The Bitcoin Core developers" at the top of the
+file in either Python or C++ style as determined by the file extension. If the
+file is a Python file and it has a '#!' starting the first line, the header is
+inserted in the line below it.
+
+The copyright dates will be set to be:
+
+"<year_introduced>-<current_year>"
+
+where <year_introduced> is according to the 'git log' history. If
+<year_introduced> is equal to <current_year>, the date will be set to be:
+
+"<current_year>"
+
+If the file already has a copyright for "The Bitcoin Core developers", the
+script will exit.
+
+Usage:
+    $ ./copyright_header.py insert <file>
+
+Arguments:
+    <file> - A source file in the bitcoin repository.
+"""
+
+def insert_cmd(argv):
+    if len(argv) != 3:
+        sys.exit(INSERT_USAGE)
+
+    filename = argv[2]
+    if not os.path.isfile(filename):
+        sys.exit("*** bad filename: %s" % filename)
+    _, extension = os.path.splitext(filename)
+    if extension not in ['.h', '.cpp', '.cc', '.c', '.py']:
+        sys.exit("*** cannot insert for file extension %s" % extension)
+   
+    if extension == '.py': 
+        style = 'python'
+    else:
+        style = 'cpp'
+    exec_insert_header(filename, style)
+         
+################################################################################
+# UI
+################################################################################
+
+USAGE = """
+copyright_header.py - utilities for managing copyright headers of 'The Bitcoin
+Core developers' in repository source files.
+
+Usage:
+    $ ./copyright_header <subcommand>
+
+Subcommands:
+    report
+    update
+    insert
+
+To see subcommand usage, run them without arguments.
+"""
+
+SUBCOMMANDS = ['report', 'update', 'insert']
+
+if __name__ == "__main__":
+    if len(sys.argv) == 1:
+        sys.exit(USAGE)
+    subcommand = sys.argv[1]
+    if subcommand not in SUBCOMMANDS:
+        sys.exit(USAGE)
+    if subcommand == 'report':
+        report_cmd(sys.argv)
+    elif subcommand == 'update':
+        update_cmd(sys.argv)
+    elif subcommand == 'insert':
+        insert_cmd(sys.argv)
diff --git a/contrib/devtools/fix-copyright-headers.py b/contrib/devtools/fix-copyright-headers.py
deleted file mode 100755
index 54836bd83f..0000000000
--- a/contrib/devtools/fix-copyright-headers.py
+++ /dev/null
@@ -1,67 +0,0 @@
-#!/usr/bin/env python3
-"""
-Run this script to update all the copyright headers of files
-that were changed this year.
-
-For example:
-
-// Copyright (c) 2009-2012 The Bitcoin Core developers
-
-it will change it to
-
-// Copyright (c) 2009-2015 The Bitcoin Core developers
-"""
-import subprocess
-import time
-import re
-
-CMD_GIT_LIST_FILES = ['git', 'ls-files']
-CMD_GIT_DATE = ['git', 'log', '--format=%ad', '--date=short', '-1']
-CMD_PERL_REGEX = ['perl', '-pi', '-e']
-REGEX_TEMPLATE = 's/(20\\d\\d)(?:-20\\d\\d)? The Bitcoin/$1-%s The Bitcoin/'
-
-FOLDERS = ["qa/", "src/"]
-EXTENSIONS = [".cpp",".h", ".py"]
-
-
-def get_git_date(file_path):
-    d = subprocess.run(CMD_GIT_DATE + [file_path],
-                       stdout=subprocess.PIPE,
-                       check=True,
-                       universal_newlines=True).stdout
-    # yyyy-mm-dd
-    return d.split('-')[0]
-
-
-def skip_file(file_path):
-    for ext in EXTENSIONS:
-        if file_path.endswith(ext):
-            return False
-    else:
-        return True
-
-if __name__ == "__main__":
-    year = str(time.gmtime()[0])
-    regex_current = re.compile("%s The Bitcoin" % year)
-    n = 1
-    for folder in FOLDERS:
-        for file_path in subprocess.run(
-            CMD_GIT_LIST_FILES + [folder],
-            stdout=subprocess.PIPE,
-            check=True,
-            universal_newlines=True
-        ).stdout.split("\n"):
-            if skip_file(file_path):
-                # print(file_path, "(skip)")
-                continue
-            git_date = get_git_date(file_path)
-            if not year == git_date:
-                # print(file_path, year, "(skip)")
-                continue
-            if regex_current.search(open(file_path, "r").read()) is not None:
-                # already up to date
-                # print(file_path, year, "(skip)")
-                continue
-            print(n, file_path, "(update to %s)" % year)
-            subprocess.run(CMD_PERL_REGEX + [REGEX_TEMPLATE % year, file_path], check=True)
-            n = n + 1