How do I iterate over all lines of files passed on the command line?

Question

I usually do this in Perl:

whatever.pl

while(<>) {
    #do whatever;
}

then cat foo.txt | whatever.pl

Now, I

Answer 1

I hate to beat a dead horse, but may I suggest using a pure function?

import sys

def main(stdin):
  for line in stdin:
    print("You said: " + line.strip())

if __name__ == "__main__":
  main(sys.stdin)

This approach is nice because main is dependent purely on its input and you can unit test it with anything that obeys the line-delimited input stream paradigm.