isalnum(3)                          CLIX                          isalnum(3)



  NAME

    isalnum - Tests whether a character is alphanumeric

  LIBRARY

    Standard C Library (libc.a)

  SYNOPSIS

    #include <ctype.h>

    int isalnum(
      int c );

  PARAMETERS

    c   An integer representing a character

  DESCRIPTION

    The isalnum() macro tests for a character for which isalpha() or isdigit()
    is true or others, as defined as defined by the character set.  The
    isalnum() 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 isalnum() does a table lookup.

  EXAMPLES

    To test if the character read from stdin is alphanumeric:

    #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 (isalnum(c))
    {
          printf("read an alphabetic character\n");
    }


  CAUTIONS




  2/94 - Intergraph Corporation                                              1

  isalnum(3)                          CLIX                          isalnum(3)



    If the argument to any character handling macro is not in the domain of
    the function, the result is undefined.

  RETURN VALUES

    The isalnum() 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),
    isspace(3), iscntrl(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