xref: /freebsd/lib/libc/locale/isxdigit.3 (revision 4f29da19bd44f0e99f021510460a81bf754c21d2)
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36.\"     @(#)isxdigit.3	8.1 (Berkeley) 6/4/93
37.\" $FreeBSD$
38.\"
39.Dd July 17, 2005
40.Dt ISXDIGIT 3
41.Os
42.Sh NAME
43.Nm isxdigit, ishexnumber
44.Nd hexadecimal-digit character test
45.Sh LIBRARY
46.Lb libc
47.Sh SYNOPSIS
48.In ctype.h
49.Ft int
50.Fn isxdigit "int c"
51.Ft int
52.Fn ishexnumber "int c"
53.Sh DESCRIPTION
54The
55.Fn isxdigit
56function tests for any hexadecimal-digit character.
57Regardless of locale, this includes the following characters only:
58.Pp
59.Bl -column \&``0''______ \&``0''______ \&``0''______ \&``0''______ \&``0''______
60.It "\&``0''\t``1''\t``2''\t``3''\t``4''"
61.It "\&``5''\t``6''\t``7''\t``8''\t``9''"
62.It "\&``A''\t``B''\t``C''\t``D''\t``E''"
63.It "\&``F''\t``a''\t``b''\t``c''\t``d''"
64.It "\&``e''\t``f''"
65.El
66.Pp
67The
68.Fn ishexnumber
69function behaves similarly to
70.Fn isxdigit ,
71but may recognize additional characters,
72depending on the current locale setting.
73.Pp
74The value of the argument must be representable as an
75.Vt "unsigned char"
76or the value of
77.Dv EOF .
78.Sh RETURN VALUES
79The
80.Fn isxdigit
81function returns zero if the character tests false and
82returns non-zero if the character tests true.
83.Sh COMPATIBILITY
84The
85.Bx 4.4
86extension of accepting arguments outside of the range of the
87.Vt "unsigned char"
88type in locales with large character sets is considered obsolete
89and may not be supported in future releases.
90The
91.Fn iswxdigit
92function should be used instead.
93.Sh SEE ALSO
94.Xr ctype 3 ,
95.Xr iswxdigit 3 ,
96.Xr ascii 7
97.Sh STANDARDS
98The
99.Fn isxdigit
100function conforms to
101.St -isoC .
102.Sh HISTORY
103The
104.Fn ishexnumber
105function appeared in
106.Bx 4.4 .
107