ISALNUM(P)                                                                             ISALNUM(P)



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  func-
       tion 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()  ,  iss-
       pace()  ,  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 orig-
       inal Standard can be obtained online at http://www.opengroup.org/unix/online.html .



POSIX                                          2003                                    ISALNUM(P)