clickinout.py

import click

@click.command()
@click.argument('input', type=click.File('rb'), nargs=-1)
@click.argument('output', type=click.File('wb'))
def cli(input, output):
    for f in input:
        while True:
            chunk = f.read(1024)
            if not chunk:
                break
            output.write(chunk)
            output.flush()
            
if __name__ == '__main__':
    cli()

docoptinout.py

"""Inout

Usage:
  inout.py <output> <input>...

Options:
  --help  Show this message and exit.
"""
import sys
import docopt

def cli():
    x = docopt.docopt(__doc__)
    if x['<output>'] == '-':
        out = sys.stdout
        close_out = False
    else:
        try:
            out = open(x['<output>'])
        except OSError as e:
            print 'error: %s' % e
            sys.exit(1)
        close_out = True
    
    try:
        for filename in x['<input>']:
            if filename == '-':
                f = sys.stdin
                close_f = False
            else:
                try:
                    f = open(x['<input>'])
                except OSError as e:
                    print 'error: %s' % e
                    sys.exit(1)
                close_f = True
    
            try:
                while True:
                    chunk = f.read(1024)
                    if not chunk:
                        break
                    out.write(chunk)
                    out.flush()
            finally:
                if close_f:
                    f.close()
    finally:
        if close_out:
            out.close()

if __name__ == '__main__':
    cli()