Hi there!!
I would try to run your program with valgrind, a memory checker tool really
useful. I'll probably need to recompile with -g flag.
Have you checked that MAX_INT (limits.h) is bigger than 300000??? I guess it
is, cause other way you would never get the "Success" message.
Let me make some comments on your code:
> If I comment out the 2 fseek statements, then I don't see any memory
> increase.
>
> The file size is about 700KB.
>
> I was wondering if someone can tell me if this is a known issue or if I'm
>
> doing something wrong.
>
> Thanks,
> Khoa.
>
> ======Source file, compiled with gcc=========
>
> #include <stdio.h>
> #include <errno.h>
>
> int main()
> {
> FILE * ptr = NULL;
> int count = 0;
>
> ptr = fopen("myBinaryFile","r");
>
if(ptr=NULL){
perror("fopen");
return ERROR;
}
while (ptr != NULL && count++ < 300000)
> {
> usleep(1000);
>
> if (fseek(ptr, 0, SEEK_END))
>
>
{
//printf("Error 1: %d\n", errno);
perror("fseek");
break;
}
> if (fseek(ptr, 0, SEEK_SET))
>
{
//printf("Error 2: %d\n", errno);
perror("fseek");
break;
}
/*Since you are using the errno.h library, you should use the perror
function, since it's the function provided by errno.h and uses the standard
error output, which is unbuffered, unlike printf, which uses stdout so the
messages you print could be buffered (but you should see any error messages
since you are ending your error messages by "/n" and anyway, any buffered
message should be printed before the "Success").*/
>
> /*if (fclose(ptr))
> break;*/
>
if(ptr){ //Check ptr is not NULL
if(fclose(ptr)==EOF){
perror("fclose");
return ERROR;
}
ptr=NULL;
}
>
> usleep(10000);
>
> ptr = fopen("myBinaryFile","r");
>
if(ptr==NULL){
perror("fopen");
return ERROR;
}
> }
>
> //fclose(ptr);
>
if(ptr){ //Check ptr is not NULL
if(fclose(ptr)==EOF){
perror("fclose");
return ERROR;
}
ptr=NULL;
}
>
> if (count >= 300000)
> print("Success\n");
>
> return 0;
> }
>
>
BTW, why are you opening your file with the "r" mode, which set the stream
position at the beginning of the file, then move the stream position to the
end of the file, and then move it again to the beginning? Why do you close
and open the file in each iteration of the while loop?? How can you see your
program is using 6MB after execution?? If your program prints "Success" and
executes "return 0;", the OS should release all the process resources.
I think your best option is to use valgrind, but I don't understand the
sense of your code...
Good luck.
Fernando.
--
---------------------------------------------------------------------------------------------------------
Fernando Campos Del Pozo
Becario Super-computación
Departamento de Física Teórica
Universidad Autónoma de Madrid
Tlf.: +34-914974893
e-mail: [email protected]
http://rincon.uam.es/dir?cw=999890136718750
