NAME

       isalnum - test for an alphanumeric character

SYNOPSIS

       #include <ctype.h>

       int isalnum(int c);

DESCRIPTION

       The  isalnum()  function  shall  test  whether  c is a character of class alpha or digit in the program's
       current locale; see the Base Definitions volume of IEEE Std 1003.1-2001, Chapter 7, Locale.

       The c argument is an int, the value of which the application shall ensure is representable as an unsigned
       char  or  equal  to  the  value  of  the  macro EOF. If the argument has any other value, the behavior is
       undefined.

RETURN VALUE

       The isalnum() function shall return non-zero if c is  an  alphanumeric  character;  otherwise,  it  shall
       return 0.

ERRORS

       No errors are defined.

       The following sections are informative.

EXAMPLES

       None.

APPLICATION USAGE

       To  ensure  applications  portability,  especially across natural languages, only this function and those
       listed in the SEE ALSO section should be used for character classification.

RATIONALE

       None.

FUTURE DIRECTIONS

       None.

SEE ALSO

       isalpha() , iscntrl() , isdigit() , isgraph() , islower() , isprint() , ispunct() , isspace() , isupper()
       ,  isxdigit()  ,  setlocale()  ,  the Base Definitions volume of IEEE Std 1003.1-2001, Chapter 7, Locale,
       <ctype.h>, <stdio.h>

COPYRIGHT

       Portions of this text are reprinted and reproduced in electronic form from IEEE Std 1003.1, 2003 Edition,
       Standard  for  Information Technology -- Portable Operating System Interface (POSIX), The Open Group Base
       Specifications Issue 6, Copyright (C) 2001-2003 by the Institute of Electrical and Electronics Engineers,
       Inc  and  The  Open Group. In the event of any discrepancy between this version and the original IEEE and
       The Open Group Standard, the original IEEE and The Open Group  Standard  is  the  referee  document.  The
       original Standard can be obtained online at http://www.opengroup.org/unix/online.html .