How can I run an executable program and send it input in one line on command line?

Question

Say, I have a program called "tree". It takes as input a text file containing some dictionary of English words, call it engDict.txt.

In my terminal, I would execute this program using the following command:

>> ./tree engDict.txt

Assuming this program automatically reads in the file and processed it. Then, it prompts the user: Would you like to exit the program (y/n)?

Now, my question is:

How can I send input to this program in one line?

For example, I tried the following, but it doesn't do what I'd like.

>> ./tree engDict.txt | n

or

>> ./tree engDict.txt ; n

You don't really need the c++ tag there. This is basically a nix question. — Matt
– Matt, Commented Aug 22, 2017 at 21:42

Walter A · Accepted Answer · 2017-08-22 21:41:46Z

2

Close. The letter n should be written to the input.

  echo n | ./tree engDict.txt

answered Aug 22, 2017 at 21:41

Walter A

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