1 #include <stdio.h> 2 #include <windows.h> 3 4 void usage(int freq_min, int freq_max){ 5 printf("usage: beep.exe frequency duration\n"); 6 printf(" frequency hertz (values between %d and %d are allowed)\n", freq_min, freq_max); 7 printf(" duration milliseconds\n\n"); 8 exit(1); 9 } 10 11 int main(int arg, char *argv[], char *envp[]){ 12 int freq_min=37, freq_max=20000; 13 if(arg<3) usage(freq_min, freq_max); 14 int freq=atol(argv[1]); 15 int duration=atol(argv[2]); 16 if(freq<freq_min || freq>freq_max || duration<0) usage(freq_min, freq_max); 17 bool beeped=Beep(freq, duration); 18 if(!beeped){ 19 printf(" an error occured\n"); 20 exit(1); 21 } 22 return 0; 23 }