how to redirect `cat` to simulate user input in linux

Question

I began a project. In the instruction, it is written that we could test our program with this command line :

cat test.txt > test.py

But I have no output. As I understood, it is supposed to give me an output.

test.txt file looks like :

And the test.py file looks like :

for i in range(16):
    var=raw_input("type something : ")
    print var

I was excepting this command line to redirect the content of the test.txt file to the test.py file while it was running.

I have already read the documentation about the cat command.

Could you help me please ?

In other words, how the cat command is supposed to simulate the user ? I think I have to change something in my python file.

Thank in advance, Mff

you just blew away test.py... you want to use "|" rather than ">" — sjr, Oct 15 '12 at 00:19
have you tried searching? http://stackoverflow.com/questions/9708484/python-use-input-from-another-command?rq=1 — muratgu, Oct 15 '12 at 00:19
Yep, that's it. I'm sorry I wasn't able to figurate this by myself :). Thank you ! — Malik Fassi, Oct 15 '12 at 00:26

score 6 · Accepted Answer · answered Oct 15 '12 at 00:21

The problem here is that you want cat test.txt | test.py rather than >. | sends the output of one command (cat test.txt) to the input of the other (test.py) whereas > sends the output to a file (which probably means you've overwritten test.py with the contents of test.txt).

how to redirect `cat` to simulate user input in linux

1 Answers1