C库函数 iscntrl()

#include <stdio.h>

#include <ctype.h>



int main () {

   int i = 0, j = 0;

   char str1[] = "all \a about \t programming";

   char str2[] = "tutorials \n point";



   /* Prints string till control character \a */

   while( !iscntrl(str1[i]) ) {

      putchar(str1[i]);

      i++;

   }



   /* Prints string till control character \n */

   while( !iscntrl(str2[j]) ) {

      putchar(str2[j]);

      j++;

   }



   return(0);

}