I'm trying to read from stdin. Here I simulate a process that slowly
outputs data to stdout:
steve@runes:~$ cat out.py
import time
print "Hello..."
time.sleep(10)
print "World!"
time.sleep(10)
print "Goodbye!"
and another process that reads from stdin:
steve@runes:~$ cat slurp.py
import sys
import time
for line in sys.stdin:
print time.ctime(), line
When I pipe one to the other, I expect each line to be printed as they
arrive, but instead they all queue up and happen at once:
steve@runes:~$ python out.py | python slurp.py
Wed Aug 27 15:13:44 2014 Hello...
Wed Aug 27 15:13:44 2014 World!
Wed Aug 27 15:13:44 2014 Goodbye!
(Note how the time stamps are all together, instead of ten seconds apart.)
Why is this happening?
How can I read from sys.stdin "on the fly", so to speak, without waiting
for the first process to end?
Is there established terminology for talking about this sort of thing?
--
Steven
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