Implementation of iscntrl() in C language

[Servant]

Hi, I am working in the xyz company as software tester. I have the knowledge of the functions of C language. But I can not know anything about the iscntrl() function of C language. So, I would like to know about the iscntrl() function. I also would like to know how can I implement the iscntrl() function in the program. So, Can anyone help me to know about the iscntrl() function.

[opaper]

Any control characters can be checked by using the iscntrl() function in the C language. The value of the particular character can be from the 0 to 31 can called the control character. The iscntrl() function can returns the zero if the value of the argument can not be the control character. The iscntrl() function can returns the non-zero if the value of the argument can be the control character.

[MindSpace]

These code of lines can guide you that how the iscntrl() function can works :

#include <stdio.h>
#include <ctype.h>
char ch[] = {'A', 0x09, 'Z'};
#define SIZE sizeof( ch ) / sizeof( char )
void main()
  {
    int a;
    for( a = 0; a < SIZE; a++ ) 
{
      printf( "Char %c is %sa Control character\n",
        chars[a],
        ( iscntrl( ch[a] ) ) ? "" : "not " );
    }
  }

Output of the above code as :

Char A is not a Control character
Char     is a Control character
Char Z is not a Control character

[Modifier]

Example :

#include <stdio.h>
#include <ctype.h>
int main ()
{
  int j=0;
  char sr[]="first line \n second line \n";
  while (!iscntrl(sr[j]))
  {
    putchar (sr[j]);
    j++;
  }
  return 0;
}

The above code of lines can prints until a control character that can breaks the while loop can arise, string character by character.

[Praetor]

The Program states the behavior of the iscntrl() function as follows :

#include <stdio.h>
int main() 
{
  if( iscntrl( 'a' ) )
  {
     printf( "Character a is not control character\n" );
  }
  if( iscntrl( '\n' ) )
  {
     printf( "Character \n is control chracter\n" );
  }
  return 0;
}

The above program produce the following output :

Character \n is control chracter

[Katty]

The iscntrl() function can returns the non-zero if the argument of the iscntrl() function can be the any of the following :

BEL BS CR FF HT NL VT

The following can be the syntax of the iscntrl() function :

#include <stdio.h>
int iscntrl(int s);