Using C++ to run a Console APP?

I'd like to use C++ to run a console app (telnet), but to change the input everytime. I want to do this to speed up the manual input (typing) into the program. Pseudocode for this would be

Code:

---

int TRY=1;
char YN

do
{
Run Program Telnet
Input "o" into Telnet
Input 'ENTER' into Telnet
Input "111.111.111.111"<<TRY  into Telnet
TRY++
Ask to do again
}while (YN='y')

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How would I accomplish this?

You want to look into piping, me thinks. You can call a program from the command line, and specify a file to be used as the standard input from the program. Instead of waiting for input for the keyboard, it will take the next piece of data from the file and use that instead. The same rules apply for getting data. If a function you use to get data from the keyboard would stop at a white space character or a new line, it would stop at the same character in the file.

You can run the program and pipe input to it using the system command. Like this (been a while since I piped - this is just a general idea - research it for your OS first).

Code:

---

#include <cstdio>
...
    system("Telnet | input.txt");

---

There's a similar method for specifying a file to be used as output. You can also have one program use another output for input and vice-versa. Very fun stuff.

Quote:

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Originally Posted by sean_mackrory

You want to look into piping, me thinks. You can call a program from the command line, and specify a file to be used as the standard input from the program. Instead of waiting for input for the keyboard, it will take the next piece of data from the file and use that instead. The same rules apply for getting data. If a function you use to get data from the keyboard would stop at a white space character or a new line, it would stop at the same character in the file.

You can run the program and pipe input to it using the system command. Like this (been a while since I piped - this is just a general idea - research it for your OS first).

Code:

---

#include <cstdio>
...
    system("Telnet | input.txt");

---

There's a similar method for specifying a file to be used as output. You can also have one program use another output for input and vice-versa. Very fun stuff.

---

Isn't it:

Code:

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system("Telnet < input.txt");

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that redirects input to come from the file "input.txt"? The other way will not do anything, maybe an error since input.txt is not a program that can be piped to ("'input.txt' is not recognized as an internal or external command, operable program or batch file" is the message I get on my machine WinXP).

On POSIX, popen would be what you're looking for to dynamically create input and examine output (as you'd probably want in an interactive GUI frontend to a console app). On Windows, I think popen doesn't exist. CreateProcess can redirect the standard streams, though.

Quote:

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Originally Posted by CornedBee

On Windows, I think popen doesn't exist. CreateProcess can redirect the standard streams, though.

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Although I believe _popen does exist (never used it personally).