locale.h頭文件定義了特定的位置設置，如日期格式和貨幣符號。有一個重要的結構struct lconv和兩個重要的函數，下麵列出一些宏定義。

庫宏

以下是在標頭中定義的宏，這些宏將被用在下麵列出的兩個函數：

S.N.	宏及說明
1	LC_ALL Set everything.
2	LC_COLLATE Affects strcoll and strxfrm functions.
3	LC_CTYPE Affects all character functions.
4	LC_MONETARY Affects the monetary information provided by localeconv function.
5	LC_NUMERIC Affects decimal-yiibai formatting and the information provided by localeconv function.
6	LC_TIME Affects the strftime function.

庫函數

以下是頭locale.h中定義的函數：

S.N.	功能及說明
1	char *setlocale(int category, const char *locale) 設置或讀取位置相關的信息。
2	struct lconv *localeconv(void) 設置或讀取位置相關的信息。

庫結構

typedef struct {
   char *decimal_yiibai;
   char *thousands_sep;
   char *grouping;	
   char *int_curr_symbol;
   char *currency_symbol;
   char *mon_decimal_yiibai;
   char *mon_thousands_sep;
   char *mon_grouping;
   char *positive_sign;
   char *negative_sign;
   char int_frac_digits;
   char frac_digits;
   char p_cs_precedes;
   char p_sep_by_space;
   char n_cs_precedes;
   char n_sep_by_space;
   char p_sign_posn;
   char n_sign_posn;
} lconv

以下是每個字段的描述：

S.N.	字段＆說明
1	decimal_yiibai Decimal yiibai character used for non-monetary values.
2	thousands_sep Thousands place separator character used for non-monetary values..
3	grouping A string that indicates the size of each group of digits in non-monetary quantities. Each character represents an integer value which designates the number of digits in the current group. A value of 0 means that the previous value is to be used for the rest of the groups.
4	int_curr_symbol A string of the international currency symbols used. The first three characters are those specified by ISO 4217:1987 and the fourth is the character which separates the currency symbol from the monetary quantity.
5	currency_symbol The local symbol used for currency.
6	mon_decimal_yiibai The decimal yiibai character used for monetary values.
7	mon_thousands_sep The thousands place grouping character used for monetary values.
8	mon_grouping A string whose elements define the size of the grouping of digits in monetary values. Each character represents an integer value which designates the number of digits in the current group. A value of 0 means that the previous value is to be used for the rest of the groups.
9	positive_sign The character used for positive monetary values.
10	negative_sign The character used for negative monetary values.
11	int_frac_digits Number of digits to show after the decimal yiibai in international monetary values.
12	frac_digits Number of digits to show after the decimal yiibai in monetary values.
13	p_cs_precedes If equal to 1, then the currency_symbol appears before a positive monetary value. If equal to 0, then the currency_symbol appears after a positive monetary value.
14	p_sep_by_space If equal to 1, then the currency_symbol is separated by a space from a positive monetary value. If equal to 0, then there is no space between the currency_symbol and a positive monetary value.
15	n_cs_precedes If equal to 1, then the currency_symbol precedes a negative monetary value. If equal to 0, then the currency_symbol succeeds a negative monetary value.
16	n_sep_by_space If equal to 1, then the currency_symbol is separated by a space from a negative monetary value. If equal to 0, then there is no space between the currency_symbol and a negative monetary value.
17	p_sign_posn Represents the position of the positive_sign in a positive monetary value.
18	n_sign_posn Represents the position of the negative_sign in a negative monetary value.

使用以下值為p_sign_posn和n_sign_posn：

值	描述
0	括號封裝值和CURRENCY_SYMBOL的。the currency_symbol.
1	符號之前的值和currency_symbol.
2	該標誌成功的值和currency_symbol.
3	符號立即之前的值和 currency_symbol.
4	符號立即成功的值和currency_symbol.