Understanding setvbuf()

Hello,

I am right now learning about file I/O operations using C through Prata's book. Right now I am on Chapter 13 of it.


I am unable to understand where setvbuf() can be used. I understand that we can control buffering with it but how can it be done? Can someone please give a small example of this function in action?

I have searched on the internet and I have not been able to find a clear example.

Regards,
Ishan

I am not sure if it is worth for a beginner to bother about.
But if you insist, there is an example: C library function - setvbuf() - Tutorialspoint

I have gone through that example earlier, but did not understand it.

Code:

---

/* compare these */

#include <stdio.h>
#include <unistd.h>

void no_buffering()
{
    setvbuf(stdout, NULL, _IONBF, 0);

    for (char c = 0x61; c < 0x7b; ++c)
    {
        putchar(c);
        usleep(1e5);
    }
}

void line_buffering()
{
    setlinebuf(stdout); // default

    for (char c = 0x61; c < 0x7b; ++c)
    {
        putchar(c);
        usleep(1e5);
    }
}

int main(void)
{
    line_buffering();

    no_buffering();
}

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