About this function

[dgottipati]

hai,


could any one explian me abt this function and what it does?

i found it in a program so i am posting it as it is.

void setraw(struct termio &tty) { struct termio oldtty; oldtty = tty; oldtty.c_lflag &= ~ICANON; oldtty.c_lflag &= ~ECHO; oldtty.c_cc[VTIME] = 0; oldtty.c_cc[VMIN] = 1; ioctl(0, TCSETA, &oldtty); } void setcanon(struct termio &tty) { ioctl(0, TCSETA, &tty); }
thanks in advance.

BYE
Dinnu.

[tyreld]

These two functions can be used to disable/renable echoing of input to a terminal console (SVR4 based Unixes, this is not compatible with BSD). Generally, you would use this in a utility that gets a password from a user. The effect is that no input is echoed to the console to prevent over the shoulder password theft. The setraw function turns off echo, while setcanon restores it.

#include <sys/ioctl.h>
#include <termio.h>
#include <stdio.h>
 
void setraw(struct termio tty) {
  struct termio oldtty;
  oldtty = tty;
  oldtty.c_lflag &= ~ICANON;
  oldtty.c_lflag &= ~ECHO;
  oldtty.c_cc[VTIME] = 0;
  oldtty.c_cc[VMIN] = 1;
  ioctl(0, TCSETA, &oldtty);
}
 
void setcanon(struct termio tty) {
  ioctl(0, TCSETA, &tty);
}
 
int main(int argc, char **argv)
{
  struct termio tty;
  char buf[1024];
 
  // Get current terminal attributes
  ioctl(0, TCGETA, &tty);
 
  printf("Enter some text : ");
 
  // Turn of echo on terminal
  setraw(tty);
 
  scanf("%s", &buf);
 
  // Restore old terminal settings with echo
  setcanon(tty);
 
  printf("\nDid you see anything?\n");
 
  return 0;
}