xref: /freebsd/lib/libc/locale/setlocale.3 (revision 3c5ba95ad12285ad37c182a4bfc1b240ec6d18a7)
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31.\"	@(#)setlocale.3	8.1 (Berkeley) 6/9/93
32.\" $FreeBSD$
33.\"
34.Dd November 21, 2003
35.Dt SETLOCALE 3
36.Os
37.Sh NAME
38.Nm setlocale
39.Nd natural language formatting for C
40.Sh LIBRARY
41.Lb libc
42.Sh SYNOPSIS
43.In locale.h
44.Ft char *
45.Fn setlocale "int category" "const char *locale"
46.Sh DESCRIPTION
47The
48.Fn setlocale
49function sets the C library's notion
50of natural language formatting style
51for particular sets of routines.
52Each such style is called a
53.Sq locale
54and is invoked using an appropriate name passed as a C string.
55.Pp
56The
57.Fn setlocale
58function recognizes several categories of routines.
59These are the categories and the sets of routines they select:
60.Bl -tag -width LC_MONETARY
61.It Dv LC_ALL
62Set the entire locale generically.
63.It Dv LC_COLLATE
64Set a locale for string collation routines.
65This controls alphabetic ordering in
66.Fn strcoll
67and
68.Fn strxfrm .
69.It Dv LC_CTYPE
70Set a locale for the
71.Xr ctype 3
72and
73.Xr multibyte 3
74functions.
75This controls recognition of upper and lower case,
76alphabetic or non-alphabetic characters,
77and so on.
78.It Dv LC_MESSAGES
79Set a locale for message catalogs, see
80.Xr catopen 3
81function.
82.It Dv LC_MONETARY
83Set a locale for formatting monetary values;
84this affects the
85.Fn localeconv
86function.
87.It Dv LC_NUMERIC
88Set a locale for formatting numbers.
89This controls the formatting of decimal points
90in input and output of floating point numbers
91in functions such as
92.Fn printf
93and
94.Fn scanf ,
95as well as values returned by
96.Fn localeconv .
97.It Dv LC_TIME
98Set a locale for formatting dates and times using the
99.Fn strftime
100function.
101.El
102.Pp
103Only three locales are defined by default,
104the empty string
105.Li \&"\|"
106which denotes the native environment, and the
107.Li \&"C"
108and
109.Li \&"POSIX"
110locales, which denote the C language environment.
111A
112.Fa locale
113argument of
114.Dv NULL
115causes
116.Fn setlocale
117to return the current locale.
118By default, C programs start in the
119.Li \&"C"
120locale.
121The only function in the library that sets the locale is
122.Fn setlocale ;
123the locale is never changed as a side effect of some other routine.
124.Sh RETURN VALUES
125Upon successful completion,
126.Fn setlocale
127returns the string associated with the specified
128.Fa category
129for the requested
130.Fa locale .
131The
132.Fn setlocale
133function returns
134.Dv NULL
135and fails to change the locale
136if the given combination of
137.Fa category
138and
139.Fa locale
140makes no sense.
141.Sh FILES
142.Bl -tag -width /usr/share/locale/locale/category -compact
143.It Pa $PATH_LOCALE/ Ns Em locale/category
144.It Pa /usr/share/locale/ Ns Em locale/category
145locale file for the locale
146.Em locale
147and the category
148.Em category .
149.El
150.Sh ERRORS
151No errors are defined.
152.Sh SEE ALSO
153.Xr colldef 1 ,
154.Xr mklocale 1 ,
155.Xr catopen 3 ,
156.Xr ctype 3 ,
157.Xr localeconv 3 ,
158.Xr multibyte 3 ,
159.Xr strcoll 3 ,
160.Xr strxfrm 3 ,
161.Xr euc 5 ,
162.Xr utf8 5 ,
163.Xr environ 7
164.Sh STANDARDS
165The
166.Fn setlocale
167function conforms to
168.St -isoC-99 .
169.Sh HISTORY
170The
171.Fn setlocale
172function first appeared in
173.Bx 4.4 .
174