xref: /freebsd/lib/libc/locale/isalpha.3 (revision acd3428b7d3e94cef0e1881c868cb4b131d4ff41)
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36.\"     @(#)isalpha.3	8.1 (Berkeley) 6/4/93
37.\" $FreeBSD$
38.\"
39.Dd July 17, 2005
40.Dt ISALPHA 3
41.Os
42.Sh NAME
43.Nm isalpha
44.Nd alphabetic character test
45.Sh LIBRARY
46.Lb libc
47.Sh SYNOPSIS
48.In ctype.h
49.Ft int
50.Fn isalpha "int c"
51.Sh DESCRIPTION
52The
53.Fn isalpha
54function tests for any character for which
55.Xr isupper 3
56or
57.Xr islower 3
58is true.
59The value of the argument must be representable as an
60.Vt "unsigned char"
61or the value of
62.Dv EOF .
63.Pp
64In the ASCII character set, this includes the following characters
65(with their numeric values shown in octal):
66.Pp
67.Bl -column \&000_``0''__ \&000_``0''__ \&000_``0''__ \&000_``0''__ \&000_``0''__
68.It "\&101\ ``A'' \t102\ ``B'' \t103\ ``C'' \t104\ ``D'' \t105\ ``E''"
69.It "\&106\ ``F'' \t107\ ``G'' \t110\ ``H'' \t111\ ``I'' \t112\ ``J''"
70.It "\&113\ ``K'' \t114\ ``L'' \t115\ ``M'' \t116\ ``N'' \t117\ ``O''"
71.It "\&120\ ``P'' \t121\ ``Q'' \t122\ ``R'' \t123\ ``S'' \t124\ ``T''"
72.It "\&125\ ``U'' \t126\ ``V'' \t127\ ``W'' \t130\ ``X'' \t131\ ``Y''"
73.It "\&132\ ``Z'' \t141\ ``a'' \t142\ ``b'' \t143\ ``c'' \t144\ ``d''"
74.It "\&145\ ``e'' \t146\ ``f'' \t147\ ``g'' \t150\ ``h'' \t151\ ``i''"
75.It "\&152\ ``j'' \t153\ ``k'' \t154\ ``l'' \t155\ ``m'' \t156\ ``n''"
76.It "\&157\ ``o'' \t160\ ``p'' \t161\ ``q'' \t162\ ``r'' \t163\ ``s''"
77.It "\&164\ ``t'' \t165\ ``u'' \t166\ ``v'' \t167\ ``w'' \t170\ ``x''"
78.It "\&171\ ``y'' \t172\ ``z''"
79.El
80.Sh RETURN VALUES
81The
82.Fn isalpha
83function returns zero if the character tests false and
84returns non-zero if the character tests true.
85.Sh COMPATIBILITY
86The
87.Bx 4.4
88extension of accepting arguments outside of the range of the
89.Vt "unsigned char"
90type in locales with large character sets is considered obsolete
91and may not be supported in future releases.
92The
93.Fn iswalpha
94function should be used instead.
95.Sh SEE ALSO
96.Xr ctype 3 ,
97.Xr islower 3 ,
98.Xr isupper 3 ,
99.Xr iswalpha 3 ,
100.Xr ascii 7
101.Sh STANDARDS
102The
103.Fn isalpha
104function conforms to
105.St -isoC .
106