new_header

#!/usr/bin/env python
import sys
import os.path

DEFAULT_HEADER_EXT = '.h'

# used for header include guard #ifndef PREFIX_THE_HEADER_POSTFIX [...]
HEADER_GUARD_PREFIX = 'CACHELOT_'
HEADER_GUARD_POSTFIX = '_H_INCLUDED'

NAMESPACE_NAME = 'cachelot'

# HEADER FILE TEMPLATE ##################################################
def HEADER_FILE_TEMPLATE(guard):
    if (NAMESPACE_NAME != ''):
        namespace_decl = """\
namespace {namespace} {{

    // Just write code

}} // namespace {namespace}""".format(namespace = NAMESPACE_NAME)
    else:
        namespace_decl = """   // Write whatever you want here"""

    return """\
#ifndef {guard}
#define {guard}

//
//  (C) Copyright 2015 Iurii Krasnoshchok
//
//  Distributed under the terms of Simplified BSD License
//  see LICENSE file


/// @ingroup <?doxygroup?>
/// @{{

{optional_namespace_declaration}

/// @}}

#endif // {guard}
""".format(guard = guard, optional_namespace_declaration = namespace_decl)
#########################################################################

def validate_filename(filename):
    import string
    valid_chars = frozenset('-_.{ascii}{digits}'.format(ascii = string.ascii_letters, digits = string.digits))
    for char in filename:
        if (not char in valid_chars): raise ValueError('Invalid character "%c" in filename' % (char,))

def case2underscore(src):
    from re import findall
    fres = findall('([a-z])([A-Z][a-z])', src)
    result = src
    for r in fres:
        s = r[0] + r[1]
        result = result.replace(r[0] + r[1], r[0]+'_'+r[1].lower())
    return result.rstrip('\n')

def guard_from_filename(header_fname):
    guard = header_fname.strip('_ ')
    guard = case2underscore(guard)
    return HEADER_GUARD_PREFIX + guard.upper() + HEADER_GUARD_POSTFIX

def generate_cxx_header(fullname):
    directory = os.path.dirname(fullname)
    filename = os.path.basename(fullname)
    validate_filename(filename)
    filename, ext = os.path.splitext(filename)
    if not ext:
        ext = DEFAULT_HEADER_EXT
    guard = guard_from_filename(filename)
    filename += ext
    return (os.path.join(directory, filename), HEADER_FILE_TEMPLATE(guard))

def usage():
    my_name = os.path.basename(sys.argv[0])
    print('usage: ' + my_name + ' HeaderName ')
    sys.exit(1)

def main():
    if len(sys.argv) != 2:
        usage()

    filename, filedata = generate_cxx_header(sys.argv[1])
    try:
        if (os.path.exists(filename)):
            sys.stderr.write('Error: file "%s" already exists' % (filename))
            sys.exit(1)
        f = open(filename, 'w')
        f.write(filedata)
        f.close()
    except IOError as e:
        sys.stderr.write( 'Error: failed to open file "%s" for write (%s)\n' % (filename, str(e)) )

if __name__ == "__main__":
    main()