UNIX for Dummies Questions & Answers

Hello!
I have an application that needs user input.
For testing, I created a text file and redirected it as input for the application.
# test_app < input.txt
This works, but never ends(keeps on getting last char), and it goes too fast.
I would like to create a script that pushes characters "somewhere", at a controlled rate, and then redirect this "somewhere" as input for the app. How do I do this?
TY!

its been a long time since i done this but think this may work in the script.

test_app < input.txt
read $variable

i dont know, you get the idea right?

Not sure I understand entirely, but the following will send your input file through a newly opened file descriptor 3 (ie. "somewhere"), then redirect it into your application at a rate of one line per second....

Code:

while read -u3 LINE
do
   echo $LINE
   sleep 1
done 3< input.txt | test_app

Hi Ygor,
I'll have to dig it a little bit but it does exactly what I need!
One thing though: I'm feeding test_app with characters, so input.txt has 1 char per line. Works good. But once input.txt has been read, test_app keeps on getting the last character. How to avoid that?
And one more question: I thought that "somewhere" could be some kind of virtual device (bridge) that I could use this way:

$ test_app < bridge

and then:
$ echo v > bridge
$ echo f > bridge
And so on, using a script.
Am I dreaming?

Thanks for your help!

"test_app keeps on getting the last character. How to avoid that?" Fix test_app. It is not detecting detecting end of file.

Is test_app a program that was written to use a tty interface? If so, you should be using "expect".

A fifo will behave more or less like the "bridge" you are describing.

"goes too fast"??? What does that mean??

test_app only uses "cin" for user input. It has not been written to be used with a file at first, I want to use a file to automate user input for testing purposes. It is intented to test the communication with a serial device. It has not been written to use the tty interface. Unfortunately, I don't know what this means.
"Going too fast" means that I want to simulate user input, so I don't want test_app to grab characters from input.txt at a very high rate. Instead, I want to feed it with characters at a fixed rate, say 1 sec.
Hope this helps helping me!
TY!

"It is intented to test the communication with a serial device. It has not been written to use the tty interface. Unfortunately, I don't know what this means."

Those first two sentences probably cannot be true at the same time. And this is probably the crux of your problem. It is probably trying to configure the tty to set baud rate, parity, flow control and stuff like that. The tty driver controls an interface that is indeed serial. And one of the options is how end of file is indicated.

What kind of serial device would the app normally talk to? And where does the user come in? Is the serial device a a terminal with a keyboard?