#!/usr/bin/python3

import sys

def _help():
    res = """Usage:
 more [options] <file>...

A file perusal filter for CRT viewing.

Options:
 -s          squeeze multiple blank lines into one
 +<number>   display file beginning from line number
 -V          display version information and exit
"""
    return res

def more(options, fname):
    exit_options = {
        '-V': lambda: 'more from util-linux 2.27'
    }
    for option in options:
        if option in exit_options:
            return exit_options[option]()
    output_options = {
        '-s': lambda s: '\n'.join([line for line in s.split('\n') if line])
    }
    with open(fname, 'r') as f:
        res = f.read()
    for option in options:
        if option in output_options:
            res = output_options[option](res)
    lines = res.split('\n')
    for i in range(0, len(lines), 30):
        print('\n'.join(lines[i:i + 30]))
        input('')
    return None

if __name__ == '__main__':
    res = None
    if len(sys.argv) < 2:
        res = _help()
    else:
        options = []
        for token in sys.argv[1:]:
            if token.startswith('-'):
                options = options + [token]
        fname = sys.argv[-1]
        res = more(options, fname)
    if res:
        print(res)