ISALPHA(3)             FreeBSD Library Functions Manual             ISALPHA(3)

NAME
     isalpha - alphabetic character test

LIBRARY
     Standard C Library (libc, -lc)

SYNOPSIS
     #include <ctype.h>

     int
     isalpha(int c);

     int
     isalpha_l(int c, locale_t loc);

DESCRIPTION
     The isalpha() function tests for any character for which isupper(3) or
     islower(3) is true.  The value of the argument must be representable as
     an unsigned char or the value of EOF.

     In the ASCII character set, this includes the following characters (with
     their numeric values shown 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_l() function takes an explicit locale argument, whereas the
     isalpha() function uses the current global or per-thread locale.

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

COMPATIBILITY
     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.

SEE ALSO
     ctype(3), islower(3), isupper(3), iswalpha(3), xlocale(3), ascii(7)

STANDARDS
     The isalpha() function conforms to ISO/IEC 9899:1990 ("ISO C90").  The
     isalpha_l() function conforms to IEEE Std 1003.1-2008 ("POSIX.1").

FreeBSD 13.1-RELEASE-p6          July 17, 2005         FreeBSD 13.1-RELEASE-p6