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simple fork() problem

 
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# 1  
Old 10-01-2010
simple fork() problem
I have this little program ...
Code:
int main(void){
  
    printf("Before");
    fork();
    printf("After");

}

output is this.....

BeforeAfterBeforeAfter

Shouldnt it be.....BeforeAfterAfter

After parent is forked child receives the copy of program and continues from next statement which is "after". Parent as well after fork continues to next statement which is "after"...

Anyone have any suggestions please
# 2  
Old 10-01-2010
use write() instead of printf(). printf() is buffered, and the child has a copy of the buffer so it also will bring "before" and then print after.

changing the first printf to
Code:
 write(1,"Before", 7);

and the second to
Code:
 write(1,"After",5);

will give you the behavior you want.
# 3  
Old 10-03-2010
Yes, FILE* s all buffered inside a process, not in the O/S, so you must flush().
# 4  
Old 10-04-2010
or simpler, properly terminate your lines:
Code:
int main(void)
{
    printf("Before\n");
    fork();
    printf("After\n");
}

 
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