Like sort(1), only in Python, and capable of sorting by line length.

hsort.py

#!/usr/bin/env python
import argparse
import os
import random
import re
import string
import sys
 
 
def number_or_zero(x):
    try:
        return float(x)
    except ValueError:
        return 0.0
 
# reduce(lambda arg, func: func(arg), [arg] + funcs)
def apply_funcs(funcs, arg):
    result = arg
    for func in funcs:
        result = func(result)
    return result
 
def main(args):
    status = os.EX_OK
    lines = []
    reverse = args.reverse
 
    for input_file in args.FILE:
        if input_file == "-":
            input_file = sys.stdin
        else:
            input_file = open(input_file, 'r')
        lines.extend(line.rstrip('\n') for line in input_file)
 
    prefilters = []
    if args.ignore_leading_blanks:
        prefilters.append(lambda x: x.lstrip())
    if args.dictionary_order:
        prefilters.append(lambda x: re.sub(
                '[^' + string.letters + string.whitespace + string.digits + ']+',
                '',
                x
            ))
    if args.ignore_case:
        prefilters.append(lambda x: x.upper())
    if args.ignore_nonprinting:
        prefilters.append(lambda x: re.sub(
                '[^' + string.printable + ']+',
                '',
                x
            ))
 
    comparison = lambda x: x
    if args.length:
        comparison = lambda x: len(x)
    elif args.numeric_sort:
        comparison = lambda x: number_or_zero(x)
 
    if args.random_sort:
        random.shuffle(lines)
    else:
        lines.sort(key=lambda line: comparison(apply_funcs(prefilters, line)), reverse=reverse)
    print("\n".join(lines))
     
    return status
 
 
if __name__ == "__main__":
    exit_code = os.EX_OK
 
    parser = argparse.ArgumentParser(
            description="Sort lines of text",
            usage="%(prog)s [OPTION]... [FILE]..."
        )
    comparison_args = parser.add_mutually_exclusive_group()
    comparison_args.add_argument('-l', '--length', help="compare by the length of each line ", action="store_true")
    comparison_args.add_argument('-n', '--numeric-sort', help="compare according to string numerical value", action="store_true")
    comparison_args.add_argument('-R', '--random-sort', help="shuffle the input, rather than sorting", action="store_true")
 
    parser.add_argument('-b', '--ignore-leading-blanks', help="ignore leading blanks", action="store_true")
    parser.add_argument('-d', '--dictionary-order', help="consider only blanks and alphanumeric characters", action="store_true")
    parser.add_argument('-f', '--ignore-case', help="fold lower case to upper case characters", action="store_true")
    parser.add_argument('-r', '--reverse', help="reverse the result of comparisons", action="store_true")
    parser.add_argument('-i', '--ignore-nonprinting', help="consider only printable characters", action="store_true")
 
    parser.add_argument('-V', '--version', action='version', version='%(prog)s 0.2')
    parser.add_argument('FILE', nargs="*", default=['-'], help="The files to be sorted. If unsupplied, or '-', reads from standard input.")
    args = parser.parse_args()
    try:
        exit_code = main(args)
    except KeyboardInterrupt:
        pass
    sys.exit(exit_code)