write() to stdout and printf output not interleaved?

Question

#include 
#define MAXLEN 256

int main() {
  int n;
  char buf[MAXLEN];
  while((n = read(0,buf,sizeof(buf))) != 0){
    printf(\"n: %d:\",n);
    wri         


        

Answer 1

You can use the std fflush() function to flush the std out buffer or you can make use of an additional \n at the end of the control string inside the printf. Something like this

printf("\n :%d:\n",n);

Its always better to use the write() & read() functions in C instead of printf() and scanf(). Printf and scanf have got some problems like printf stores the string parameter in stdout buffer. So a manual flush is required which is done through fflush function or by means of \n. In a small hello world printing program you will not find such a problem as the stdout buffer is flushed at the end of the program execution. Better use write() which works fine. scanf also have the problem of reading spaces and a lot of other problems related to stdin buffer.

For example in the code below:

main()  {   char a; int i=0,c; for(;i<2;i++) { scanf("%d",&c); scanf("%c",&a);} }

The above program as got the problem of reading \n into stdin on pressing enter. We could resolve this but not flushing the stdin buffer or making use of \n character. Always better to use the read() and write() functions.

Hope that helps....