Ctype h C Tutorial

Item Value
Header filectype.h
Declarationint iscntrl(int ch);
Returnreturns nonzero if ch is a control character or zero is returned.

#include 
  #include 
  int main(void)
  {
    char ch;
    for(;;) {
       ch = getchar( );
       if(ch == '.') {
          break;
       }
       if(iscntrl(ch)){
          printf("%c is a control char\n", ch);
       }
    }
    return 0;
  }
1
is a control char
2
is a control char
3
is a control char
.