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## 9 Locale (`locale.h`)

A locale is the name for a collection of parameters (affecting collating sequences and formatting conventions) that may be different depending on location or culture. The `"C"` locale is the only one defined in the ANSI C standard.

This is a minimal implementation, supporting only the required `"C"` value for locale; strings representing other locales are not honored. (`""` is also accepted; it represents the default locale for an implementation, here equivalent to `"C"`).

`locale.h` defines the structure `lconv` to collect the information on a locale, with the following fields:

`char *decimal_point`
  The decimal point character used to format “ordinary” numbers (all numbers except those referring to amounts of money). `"."` in the C locale.
`char *thousands_sep`
  The character (if any) used to separate groups of digits, when formatting ordinary numbers. `""` in the C locale.
`char *grouping`
  Specifications for how many digits to group (if any grouping is done at all) when formatting ordinary numbers. The numeric value of each character in the string represents the number of digits for the next group, and a value of `0` (that is, the string's trailing `NULL`) means to continue grouping digits using the last value specified. Use `CHAR_MAX` to indicate that no further grouping is desired. `""` in the C locale.
`char *int_curr_symbol`
  The international currency symbol (first three characters), if any, and the character used to separate it from numbers. `""` in the C locale.
`char *currency_symbol`
  The local currency symbol, if any. `""` in the C locale.
`char *mon_decimal_point`
  The symbol used to delimit fractions in amounts of money. `""` in the C locale.
`char *mon_thousands_sep`
  Similar to `thousands_sep`, but used for amounts of money. `""` in the C locale.
`char *mon_grouping`
  Similar to `grouping`, but used for amounts of money. `""` in the C locale.
`char *positive_sign`
  A string to flag positive amounts of money when formatting. `""` in the C locale.
`char *negative_sign`
  A string to flag negative amounts of money when formatting. `""` in the C locale.
`char int_frac_digits`
  The number of digits to display when formatting amounts of money to international conventions. `CHAR_MAX` (the largest number representable as a `char`) in the C locale.
`char frac_digits`
  The number of digits to display when formatting amounts of money to local conventions. `CHAR_MAX` in the C locale.
`char p_cs_precedes`
  `1` indicates the local currency symbol is used before a positive or zero formatted amount of money; `0` indicates the currency symbol is placed after the formatted number. `CHAR_MAX` in the C locale.
`char p_sep_by_space`
  `1` indicates the local currency symbol must be separated from positive or zero numbers by a space; `0` indicates that it is immediately adjacent to numbers. `CHAR_MAX` in the C locale.
`char n_cs_precedes`
  `1` indicates the local currency symbol is used before a negative formatted amount of money; `0` indicates the currency symbol is placed after the formatted number. `CHAR_MAX` in the C locale.
`char n_sep_by_space`
  `1` indicates the local currency symbol must be separated from negative numbers by a space; `0` indicates that it is immediately adjacent to numbers. `CHAR_MAX` in the C locale.
`char p_sign_posn`
  Controls the position of the positive sign for numbers representing money. `0` means parentheses surround the number; `1` means the sign is placed before both the number and the currency symbol; `2` means the sign is placed after both the number and the currency symbol; `3` means the sign is placed just before the currency symbol; and `4` means the sign is placed just after the currency symbol. `CHAR_MAX` in the C locale.
`char n_sign_posn`
  Controls the position of the negative sign for numbers representing money, using the same rules as `p_sign_posn`. `CHAR_MAX` in the C locale.