iscntrl(3)                          CLIX                          iscntrl(3)



  NAME

    iscntrl - Tests for a control character

  LIBRARY

    Standard C Library (libc.a)

  SYNOPSIS

    #include <ctype.h>

    int iscntrl(
      int c );

  PARAMETERS

    c   An integer representing a character

  DESCRIPTION

    The iscntrl() macro tests for control characters as defined by the
    character set.  The iscntrl() macro is defined on valid members of the
    character set and on the single value EOF (guaranteed not to be a
    character set member.  See stdio.

    The classification macro iscntrl() does a table lookup.

  EXAMPLES

    To test if the character read from stdin is a control character:

    #include <ctype.h>
    int c;
       .
       .
       .
    /* get a character from stdin */
    printf("enter a character:");
    c = getchar();

    /* check to see if a digit was read */
    if (iscntrl(c))
    {
         printf("read a control character\n");
    }


  CAUTIONS

    If the argument to any character handling macro is not in the domain of



  2/94 - Intergraph Corporation                                              1

  iscntrl(3)                          CLIX                          iscntrl(3)



    the function, the result is undefined.

  RETURN VALUES

    The iscntrl() macro returns 0 for false and nonzero numbers for true.

  RELATED INFORMATION

    Commands:  chrtbl(1)

    Functions:  isdigit(3), isxdigit(3), islower(3), isupper(3), isalpha(3),
    isalnum(3), isspace(3), ispunct(3), isprint(3), isgraph(3), isascii(3),
    tolower(3), toupper(3), toascci(3), _tolower(3), _toupper(3),
    setchrclass(3)

    Files:  stdio(3)

    Miscellany:  environ(4)




































  2                                              Intergraph Corporation - 2/94