Passing Arguments Through system() in C++

Question

How would I pass a command line variable though a system() command in c++. I have tried using:

string i;
i = system("./findName.sh");
i += argv[1];
cout << i;

But when i run this it gives me my condition for wrong number of arguments i have written in my shell script.

This is the output I received when running my program with "./findName brandonw". Which is my executable file ran with the argument i want my shell script to run with.

The arguments you put are:
brandonw
usage: findName.sh [only_one_argument]

For a start, you're trying to append it to the output, not the input. And `system` does not return a `std::string`. You need to get into the habit of consulting some _documentation_. — Lightness Races in Orbit, Sep 30 '15 at 14:54

score 1 · Answer 1 · answered Sep 30 '15 at 15:05

1

Just concatenate it to the command string.

string command = "./findName.sh";
command = command + " "  + argv[1];
system(command.c_str());

answered Sep 30 '15 at 15:05

Joey Allen

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score 0 · Answer 2 · edited May 23 '17 at 12:29

0

Just rearrange your code a bit:

string i("./findName.sh ");
i += argv[1];
system(i.c_str());
cout << i;

Also note, that system doesn't return a std::string, but an implementation defined int value.

If you need to deal with ./findName.sh's output, you rather need pipe().

edited May 23 '17 at 12:29

Community

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answered Sep 30 '15 at 15:02

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Passing Arguments Through system() in C++

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