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pythonechostdin

python cat (echo) equivalent for stdin

I thought this program will echo my console input line by line:

import os, sys

for line in sys.stdin:
    print line

Unfortunately it waits for EOF (Ctrl + D) and then it produces output. How should I modify my program to get output line by line?

Solution

  • Python 2.x:

    for line in iter(sys.stdin.readline, ''):
    print line,

    Python 3.x:

    for line in iter(sys.stdin.readline, ''):
    print(line, end='')

    See the documentation on iter() with two arguments, it actually has reading from a file like this as one of the examples.