iscntrl Function

Test for a control character.

Include

<ctype.h>

Prototype

int iscntrl(int c);

Argument

c

The character to test.

Return Value

Returns a non-zero integer value if the character, c, is a control character; otherwise, returns zero.

Remarks

A character is considered to be a control character if its ASCII value is in the range 0x00 to 0x1F inclusive, or 0x7F.

Example

#include <ctype.h>
#include <stdio.h>

int main(void)
{
  char ch;

  ch = 'B';
  if (iscntrl(ch))
    printf("B is a control character\n");
  else
    printf("B is NOT a control character\n");
 
  ch = '\t';
  if (iscntrl(ch))
    printf("A tab is a control character\n"); 
  else
    printf("A tab is NOT a control character\n");
}

Example Output

B is NOT a control character
a tab is a control character