shakeit.py

#!/usr/bin/env python
# encoding: utf-8

import random
import fileinput


def shakeit(word):
    if len(word) < 3:
        return word
    middle = list(word[1:-1])
    random.shuffle(middle)
    return word[0] + ''.join(middle) + word[-1]


for line in fileinput.input():
    print ' '.join((shakeit(word) for word in line.strip().split(' ')))

echo 'shake this'| ./shakeit.py
./shakeit.py < file.txt
./shakeit.py file1.txt file2.txt file3.txt