PROLOG | NAME | SYNOPSIS | DESCRIPTION | RETURN VALUE | ERRORS | EXAMPLES | APPLICATION USAGE | RATIONALE | FUTURE DIRECTIONS | SEE ALSO | COPYRIGHT

ISALNUM(3P)               POSIX Programmer's Manual              ISALNUM(3P)

PROLOG         top

       This manual page is part of the POSIX Programmer's Manual.  The Linux
       implementation of this interface may differ (consult the
       corresponding Linux manual page for details of Linux behavior), or
       the interface may not be implemented on Linux.

NAME         top

       isalnum, isalnum_l — test for an alphanumeric character

SYNOPSIS         top

       #include <ctype.h>

       int isalnum(int c);
       int isalnum_l(int c, locale_t locale);

DESCRIPTION         top

       For isalnum(): The functionality described on this reference page is
       aligned with the ISO C standard. Any conflict between the
       requirements described here and the ISO C standard is unintentional.
       This volume of POSIX.1‐2008 defers to the ISO C standard.

       The isalnum() and isalnum_l() functions shall test whether c is a
       character of class alpha or digit in the current locale, or in the
       locale represented by locale, respectively; see the Base Definitions
       volume of POSIX.1‐2008, 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.

       The behavior is undefined if the locale argument to isalnum_l() is
       the special locale object LC_GLOBAL_LOCALE or is not a valid locale
       object handle.

RETURN VALUE         top

       The isalnum() and isalnum_l() functions shall return non-zero if c is
       an alphanumeric character; otherwise, they shall return 0.

ERRORS         top

       No errors are defined.

       The following sections are informative.

EXAMPLES         top

       None.

APPLICATION USAGE         top

       To ensure applications portability, especially across natural
       languages, only these functions and the functions in the reference
       pages listed in the SEE ALSO section should be used for character
       classification.

RATIONALE         top

       None.

FUTURE DIRECTIONS         top

       None.

SEE ALSO         top

       isalpha(3p), isblank(3p), iscntrl(3p), isdigit(3p), isgraph(3p),
       islower(3p), isprint(3p), ispunct(3p), isspace(3p), isupper(3p),
       isxdigit(3p), setlocale(3p), uselocale(3p)

       The Base Definitions volume of POSIX.1‐2008, Chapter 7, Locale,
       ctype.h(0p), stdio.h(0p)

COPYRIGHT         top

       Portions of this text are reprinted and reproduced in electronic form
       from IEEE Std 1003.1, 2013 Edition, Standard for Information
       Technology -- Portable Operating System Interface (POSIX), The Open
       Group Base Specifications Issue 7, Copyright (C) 2013 by the
       Institute of Electrical and Electronics Engineers, Inc and The Open
       Group.  (This is POSIX.1-2008 with the 2013 Technical Corrigendum 1
       applied.) 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.unix.org/online.html .

       Any typographical or formatting errors that appear in this page are
       most likely to have been introduced during the conversion of the
       source files to man page format. To report such errors, see
       https://www.kernel.org/doc/man-pages/reporting_bugs.html .

IEEE/The Open Group                 2013                         ISALNUM(3P)

Pages that refer to this page: ctype.h(0p)isalpha(3p)isblank(3p)iscntrl(3p)isdigit(3p)isgraph(3p)islower(3p)isprint(3p)ispunct(3p)isspace(3p)isupper(3p)isxdigit(3p)setlocale(3p)