在在线c编译器中显示错误

Question

Hi all I have a c compiler up and running shows the output but the problem is that it dosen't show errors....

      shell_exec("gcc xyz.c -o ab.out ");

      $output=exec("./ab.out");
      echo $output;

So it is showing output but not any errors occurred while compiling. Any help is duly appreciated. Thanks in advance.

Answer 1

Any error output from the command you run will go to STDERR and none of the exec, shell_exec functions will provide you that. One way is to redirect it

exec("gcc test.c 2>&1", $out);

The most cleaner way is to use proc_open function.

$descriptorspec = array(
   1 => array("pipe", "w"),  // stdout
   2 => array("pipe", "w") // stderr 
);

$process = proc_open('gcc test.c', $descriptorspec, $pipes);

if (is_resource($process)) {
    $stderr = stream_get_contents($pipes[2]);
    $stdout = stream_get_contents($pipes[1]);
    fclose($pipes[1]);
    fclose($pipes[2]);
    $return_value = proc_close($process);
}