Documentation Archive Developer
ADC Home > Reference Library > Reference > Mac OS X > Mac OS X Man Pages


This document is a Mac OS X manual page. Manual pages are a command-line technology for providing documentation. You can view these manual pages locally using the man(1) command. These manual pages come from many different sources, and thus, have a variety of writing styles.

For more information about the manual page format, see the manual page for manpages(5).

ISALPHA(3)               BSD Library Functions Manual               ISALPHA(3)

     isalpha -- alphabetic character test

     Standard C Library (libc, -lc)

     #include <ctype.h>

     isalpha(int c);

     The isalpha() function tests for any character for which isupper(3) or
     islower(3) is true.  For single C chars locales (see multibyte(3)), the
     value of the argument is representable as an unsigned char or the value
     of EOF.  In the ASCII character set, this includes the following charac-ters characters
     ters (preceded by their numeric values, in octal):

     101 ``A''     102 ``B''     103 ``C''     104 ``D''     105 ``E''
     106 ``F''     107 ``G''     110 ``H''     111 ``I''     112 ``J''
     113 ``K''     114 ``L''     115 ``M''     116 ``N''     117 ``O''
     120 ``P''     121 ``Q''     122 ``R''     123 ``S''     124 ``T''
     125 ``U''     126 ``V''     127 ``W''     130 ``X''     131 ``Y''
     132 ``Z''     141 ``a''     142 ``b''     143 ``c''     144 ``d''
     145 ``e''     146 ``f''     147 ``g''     150 ``h''     151 ``i''
     152 ``j''     153 ``k''     154 ``l''     155 ``m''     156 ``n''
     157 ``o''     160 ``p''     161 ``q''     162 ``r''     163 ``s''
     164 ``t''     165 ``u''     166 ``v''     167 ``w''     170 ``x''
     171 ``y''     172 ``z''

     The isalpha() function returns zero if the character tests false and
     returns non-zero if the character tests true.

     The 4.4BSD extension of accepting arguments outside of the range of the
     unsigned char type in locales with large character sets is considered
     obsolete and may not be supported in future releases.  The iswalpha()
     function should be used instead.

     ctype(3), isalnum_l(3), islower(3), isupper(3), iswalpha(3),
     multibyte(3), ascii(7)

     The isalpha() function conforms to ISO/IEC 9899:1990 (``ISO C90'').

BSD                             August 21, 2004                            BSD