Question

I have this function, the input is the var “cmd” for example a dmesg command.

int i = 0;
char * bufferf;
bufferf = ( char * ) calloc( sizeof ( char ) , 200000 );
char buffer[1000][1280];
memset(buffer,0,1000 * 1280);
memset(bufferf,0,strlen(bufferf));
FILE* pipe = popen(cmd, "r");

if (!pipe){
    send(client_fd,"EXCEPTION",9,0);
}

while(!feof(pipe)) {
    if(fgets(buffer[i], 128, pipe) != NULL)
    {
        strcat(bufferf, buffer [i] );
    }
    i++;
}
pclose(pipe);
std::cout << bufferf ;
send(client_fd,bufferf,strlen(bufferf),0); }

Well. My goal is to calculate the amount of time between the start and the end of the while statement, by adding for each time a var that count the time passed.

For example dmesg is ~700 lines of output. The while runs for 700 times I have to add 700 times the amount of time to calculate the total sum.
How can I do that?
I’ve tried with difftime but it doesn’t work very well.
Any other solutions?

Thank you.

Answer 1

You could make an extremely basic class that uses clock() to measure the time:

#include <ctime>

class Timer
{
   private:
      clock_t _start, _duration;
   public:
      Timer() : _start(0), _duration(0) { }

      void start() { _start = clock(); }
      void stop() { _duration = clock() - _start; }     
      float getTime() { return (float)_duration / CLOCKS_PER_SEC; }
};

Obviously multiply by 1000 if you want to display the time in milliseconds.

And then just:

Timer t;
t.start();
// do something
t.stop();

cout << "Duration: " << t.getTime() << endl;

Also, take note of what sarnold said, buffer is huge.