'\n' trouble: print standard output to the text files using FILE DESCRIPTORS in C

Question

I have a doubt regarding file descriptors used in C language. I am trying to redirect standard output to a text file so that printf("") output goes in the file.

Using dup2,I have written following code snippet. The code works fine and I get 2 strings "sugar" and "spice" on screen output and "salt" is stored in the file.

But when I remove "\n" from statements: printf("sugar\n"), printf("salt\n"), printf("spice\n"),then I only get screen output as: "sugarsaltspice" and nothing is stored in the file.

Please help me regarding this as I am not able to figure out why "\n" makes a difference here.

Thanks a tonne.

#include<stdlib.h>
#include<unistd.h>
#include<stdio.h>
#include<fcntl.h>
#include<errno.h>

int main()
{
    int fd;
    int o = dup(1); //backup of STD_OUT
    fd = open("/home/Desktop/Text2.txt",O_CREAT|O_TRUNC|O_WRONLY,0);

    printf("sugar\n");

    dup2(fd,1);  //CHANGE STD_OUT to FILE
    printf("salt\n");

    dup2(o,1); //Restore STD_OUT
    printf("spice\n");

    return 0;
}