CODEWITHSUNDEEP
c++terminalxtermgnome-terminal
user2351509
user2351509

Reputation: 51

How to copy and run command in different terminal

I have a simple program, e.g. in C++

#include<iostream>
using namespace std;

int main()
{
    int a, b, c;
    cin >> a >> b;
    c = a + b;
    cout << c;
}

Here i need to give a and b as inputs at the time of execution.

I need to write a script to auto type value of a (say 5) and b (say 7) into the first terminal.

Upvotes: 0

Views: 388

Answers (3)

code_dredd
code_dredd

Reputation: 6085

Instead of trying to write a program that interacts with multiple terminals or works with pipes, which might be more complicated, I'd recommend making your program simpler by having it handle command-line arguments. You can re-write your C++ program as follows:

#include <iostream>
#include <cstdlib>    // for atoi function

using namespace std;

int main(int argc, char* argv[])  // to accept CLI inputs
{
    // argv[0] has path/name to this program
    // argv[1] has 1st argument, if provided
    // argv[2] has 2nd argument, if provided
    // if argc != 3, then we don't have everything we expected, and we bail
    if(argc != 3) {
        cerr << "usage: " << argv[0] << " arg1 arg2" << endl;
        return -1;
    }

    // for simplicity, we assume that you won't get letters, only numbers
    int a = atoi(argv[1]);
    int b = atoi(argv[2]);
    cout << (a + b);

    return 0;
}

You can then write a simple shell script to launch your program with whatever arguments you want. For example, if your built program is called test (use g++ -o test test.cpp to build), then you can use this example launcher.bash script:

#!/bin/bash

for i in {0..10}
do
    ./test $i $i
    echo
done

The script produces the following output:

/tmp ❯ ./launcher.bash
0
2
4
6
8
10
12
14
16
18
20

Upvotes: 1

Md Shibbir Hossen
Md Shibbir Hossen

Reputation: 338

I think you have to change something to do so, as you want to pass the arguments from the script. C++ program main.cpp:

 #include <iostream>
#include <stdlib.h>
using namespace std;
int main(int argc,char *argv[])
{
  if(argc==1)
   {
    exit(1);
   }
  int a=atoi(argv[1]);
   int b=atoi(argv[2]);
  cout<<a+b<<endl;
return 0;
}

and shell script will be :

 #!/bin/bash

    g++ temp.cpp -o out
    a=5
    b=2
    ./out "${a}" "${b}"

You should see here for passing variables.And see this also

Upvotes: 1

ivand58
ivand58

Reputation: 811

If the executable is a.out then you can use

a=5;b=7;echo $a $b | ./a.out

Btw, in your example the namespace for cout/cin is missing (for e.g. add using namespace std; after the #include).

Upvotes: 0

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