Time Problem

[Shynash21]

Hi friends.I have to write a program which accepts one command line argument,executes the arguments as shell command,determines the time taken by it and prints the time values.I have written a program but it is showing some errors so please tell me where i have gone wrong.

#include<time.h>
#include<sys/times.h>
#include<stdio.h>
#include<stdlib.h>
#include<unistd.h>
int main(int argc,char *argv[])
{
  int i;
   struct tms,start,end;
   clock_t t1,t2;
    static long clk_tck;
     if(argc<2)
     {
        printf("Enter the parameter list\n");
        exit(0);
     }
    clktck=sysconf(_SC_CLK_TCK);
     start=times(&t1);
      system(argv[1]);
      end=times(&t2);
       printf("Start Time:%f\n",start);
       printf("End Time :%f\n",end);
       printf("Diffrence:%f\n",((t2.tms_utime-t1.tms_utime)/clktck));
}

Errors
Line18 & 20:Passing argument 1 of times() from incompatible pointer type
Line23:Request for member tms_utime in something not a structure or union

[Peter87]

You are using t1 and t2 when you should use start and end, and vice versa.

[Shynash21]

Hello thanks for the reply.Are my lines 21 and 22 are correct?.Should i put t1 and t2 as start time and end time respectively.

[Peter87]

Yes use t1 and t2 on line 21-22.

[Shynash21]

Now if i use a command like cal it gets executed too quickly.So all the values are 0.00.Can u tell me a command which takes a bit more time to execute so that i can see the readings

./a.out cal
<cal output>
start:0.00000
end:0.000000
difference:0.0000

[Peter87]

I don't know such a command without additional flags. Why don't you just write a program that takes long time to execute yourself?

[Shynash21]

I tried to execute one of the shell scripts i wrote but i says command not found.How can i make external commands work

[Peter87]

If the executable file of the program you want to time is named foo you run it as ./a.out ./foo

[Shynash21]

ya but the script is in /home/<username>/ .....if i try like this it still says command not found

[Peter87]

Doesn't it work if you specify the whole path? ./a.out /home/<username>/ ... /foo

[Shynash21]

the file has .sh extension....it does not work if i keep or remove the extension
Output
./a.out /home/<username>/1.sh
sh: ./home/<username>/1.sh: No such file

[Shynash21]

peter i made a mistake by not putting a dot before root.Now it locates but it says permission denied.Plz tell me how to setup execute permisiion for that file.I know we have to use chmod but i don't know the parameters.