use read() to take user input instead of scanf

Question

Im trying to use the read() function to take user input but the only thing I can find in the documentation is regarding reading from files, this is in Linux c language. I also want to use write() do display something to the console.

Does anyone have any idea how this is done?

have a look here http://stackoverflow.com/questions/9610064/read-stdin-in-c — StoryTeller - Unslander Monica, Jan 31 '13 at 21:57
@lxop Probably because it's not always appropriate. (In fact, it does what we want it to do in least cases.) — , Jan 31 '13 at 22:01

score 1 · Answer 1 · answered Jan 31 '13 at 21:59

but the only thing I can find in the documentation is regarding reading from files

Don't worry, the standard input is a file.

char buf[128];
read(STDIN_FILENO, buf, sizeof(buf));

I also want to use write() do display something to the console.

Let me not repeat myself.

const char *s = "Hello World!\n";
write(STDOUT_FILENO, s, strlen(s));

score 0 · Answer 2 · answered Jan 31 '13 at 22:00

0

This here should give you an impression how to do it (0 is stdin, 1 is stdout)

#include <unistd.h>
#include <string.h>
int main () {
  char buf[100];
  char *msg="you wrote:";
  while (1) {
    int n;
    n=read (0, buf, sizeof(buf));
    write (1, msg, strlen(msg));
    write (1, buf, n);
  }
}

answered Jan 31 '13 at 22:00

pbhd

4,384
1
20
26

Be careful, this will wait until the user types 100 characters before read(2) returns. – vonbrand Feb 01 '13 at 00:18
No, it doesn't, it also returns after \n – pbhd Feb 01 '13 at 10:53

use read() to take user input instead of scanf

2 Answers2