We can use the <em>system</em> function to run an external command. The method invokes the command <a href="https://helloacm.com/how-to-async-and-await-in-c11/" title="How to Async and Await in C++11?">synchronously</a> and return the status code. Given the following C program, we first concatenate all command line paramters into a string/char buffer of size 256. And then we invoke the command string using system function from stdlib header. And return the status code as the main function.

This is just a wrapper of the command. You can echo $? to see the status code:

```
#include <stdlib.h>
#include <stdio.h>
#include <string.h>

int main(int argc, char* argv[]) {
    if (argc == 0) {
        return 0;
    }
    char cmd[255];
    int s = 0;
    for (int i = 1; i < argc; ++ i) {
        strcpy(cmd + s, argv[i]);        
        s += strlen(argv[i]);
        cmd[s ++] = ' ';
    }
    cmd[s] = '\0';
    printf("Running `%s` ...\n", cmd);
    int ret = system(cmd);
    printf("Return Code: %d\n", ret);
    return ret;
}
```

Compiling the above C source e.g. run.c
```
$ gcc run.c -o run
```

And then run:

```
$ ./run echo HelloACM.com
Running `echo HelloACM.com ` ...
HelloACM.com
Return Code: 0
$ echo $?
0
```

--EOF (<a title='The Ultimate Computing & Technology Blog' href='https://helloacm.com'>The Ultimate Computing & Technology Blog</a>) -- 


Reposted to [Blog](https://helloacm.com/c-program-to-run-external-command-using-system-synchronous/)

^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ Thank you for reading ^^^^^^^^^^^^^^^
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