How can I use a variable in a system function?
i.e. I want to make a simple little program that you can put an IP address into the program and it will ping it for you. I would do something like this:
Where would I put the variable IP?Code:int main() { double IP = 0.0; cout << "Please Enter the IP Address you Wish to Ping: "; cin >> IP; system("ping"); }
Also, would the IP be a double, seeing as there are more than one decimal place?
It wouldn't work using a variable of type double since an IP contains more than one dot, which doesn't fit the format of a double. You want to use a string instead. As for the command, you should use a string containing "ping your_ip_address".
What exactly would I do with that string?
Simply printing it out in the console won't do anything... or would it..?
You want to create buffer
command[MAX_COMMAND_LEN] of the enough lenght to store the whole command
Then you will use sprintf to build the string
sprintf(command,"ping %s", ip_address);
where ip_address is a string with desired IP
and call
system(command)
Instead of sprintf you can use snprintf (_snprintf on MSVC) to prevent buffer overflow or allocated command buffer dynamically based on the resulting command len
Or you can use some socket library (like winsock2) and build a ping packet by yourself
All problems in computer science can be solved by another level of indirection,
except for the problem of too many layers of indirection.
– David J. Wheeler
Recently asked - http://cboard.cprogramming.com/showt...ghlight=system
If you dance barefoot on the broken glass of undefined behaviour, you've got to expect the occasional cut.
If at first you don't succeed, try writing your phone number on the exam paper.
OK, thanks. I did use the search but just for this section. Also, I am using this in C++ and I see that that thread is in the C Programming section. There must be a difference.
Only in the way(s) you can construct the string to send to system().
If you dance barefoot on the broken glass of undefined behaviour, you've got to expect the occasional cut.
If at first you don't succeed, try writing your phone number on the exam paper.
