Sets the members of a structure of type struct lconv with values
appropriate for formatting numeric quantities according to the
rules of the current locale.
Format
#include <locale.h>
struct lconv *localeconv (void);
1 – Description
The localeconv function returns a pointer to the lconv structure
defined in the <locale.h> header file. This structure should
not be modified by the program. It is overwritten by calls to
localeconv, or by calls to the setlocale function that change the
LC_NUMERIC, LC_MONETARY, or LC_ALL categories.
The members of the structure are:
Member Description
char *decimal_point The radix character.
char *thousands_sep The character used to separate groups of
digits.
char *grouping The string that defines how digits are
grouped in nonmonetary values.
char *int_curr_symbol The international currency symbol.
char *currency_symbol The local currency symbol.
char *mon_decimal_ The radix character used to format
point monetary values.
char *mon_thousands_ The character used to separate groups of
sep digits in monetary values.
char *mon_grouping The string that defines how digits are
grouped in a monetary value.
char *positive_sign The string used to indicate a nonnegative
monetary value.
char *negative_sign The string used to indicate a negative
monetary value.
char int_frac_digits The number of digits displayed after
the radix character in a monetary value
formatted with the international currency
symbol.
char frac_digits The number of digits displayed after the
radix character in a monetary value.
char p_cs_precedes For positive monetary values, this is
set to 1 if the local or international
currency symbol precedes the number, and
it is set to 0 if the symbol succeeds the
number.
char p_sep_by_space For positive monetary values, this is
set to 0 if there is no space between the
currency symbol and the number. It is set
to 1 if there is a space, and it is set to
2 if there is a space between the symbol
and the sign string.
char n_cs_precedes For negative monetary values, this is
set to 1 if the local or international
currency symbol precedes the number, and
it is set to 0 if the symbol succeeds the
number.
char n_sep_by_space For negative monetary values, this is
set to 0 if there is no space between the
currency symbol and the number. It is set
to 1 if there is a space, and it is set to
2 if there is a space between the symbol
and the sign string.
char p_sign_posn An integer used to indicate where the
positive_sign string should be placed for
a nonnegative monetary quantity.
char n_sign_posn An integer used to indicate where the
negative_sign string should be placed for
a negative monetary quantity.
Members of the structure of type char* are pointers to strings,
any of which (except decimal_point) can point to "", indicating
that the associated value is not available in the current locale
or is zero length. Members of the structure of type char are
positive numbers, any of which can be CHAR_MAX, indicating that
the associated value is not available in the current locale.
CHAR_MAX is defined in the <limits.h> header file.
Be aware that the value of the CHAR_MAX macro in the <limits.h>
header depends on whether the program is compiled with the
/UNSIGNED_CHAR qualifier:
o Use the CHAR_MAX macro as an indicator of a nonavailable value
in the current locale only if the program is compiled without
/UNSIGNED_CHAR (/NOUNSIGNED_CHAR is the default).
o If the program is compiled with /UNSIGNED_CHAR, use the SCHAR_
MAX macro instead of the CHAR_MAX macro.
In /NOUNSIGNED_CHAR mode, the values of CHAR_MAX and SCHAR_MAX
are the same; therefore, comparison with SCHAR_MAX gives correct
results regardless of the /[NO]UNSIGNED_CHAR mode used.
The members grouping and mon_grouping point to a string that
defines the size of each group of digits when formatting a
number. Each group size is separated by a semicolon (;). For
example, if grouping points to the string 5;3 and the thousands_
sep character is a comma (,), the number 123450000 would be
formatted as 1,234,50000.
The elements of grouping and mon_grouping are interpreted as
follows:
Value Interpretation
CHAR_MAX No further grouping is performed.
0 The previous element is to be used repeatedly for the
remainder of the digits.
other The integer value is the number of digits that comprise
the current group. The next element is examined to
determine the size of the next group of digits before
the current group.
The values of p_sign_posn and n_sign_posn are interpreted as
follows:
Value Interpretation
0 Parentheses surround the number and currency symbol.
1 The sign string precedes the number and currency symbol.
2 The sign string succeeds the number and currency symbol.
3 The sign string immediately precedes the number and
currency symbol.
4 The sign string immediately succeeds the number and
currency symbol.
2 – Return Value
x Pointer to the lconv structure.
3 – Example
#include <stdlib.h>
#include <stdio.h>
#include <limits.h>
#include <locale.h>
#include <string.h>
/* The following test program will set up the British English */
/* locale, and then extract the International Currency symbol */
/* and the International Fractional Digits fields for this */
/* locale and print them. */
int main()
{
/* Declare variables */
char *return_val;
struct lconv *lconv_ptr;
/* Load a locale */
return_val = (char *) setlocale(LC_ALL, "en_GB.iso8859-1");
/* Did the locale load successfully? */
if (return_val == NULL) {
/* It failed to load the locale */
printf("ERROR : The locale is unknown");
exit(EXIT_FAILURE);
}
/* Get the lconv structure from the locale */
lconv_ptr = (struct lconv *) localeconv();
/* Compare the international currency symbol string with an */
/* empty string. If they are equal, then the international */
/* currency symbol is not defined in the locale. */
if (strcmp(lconv_ptr->int_curr_symbol, "")) {
printf("International Currency Symbol = %s\n",
lconv_ptr->int_curr_symbol);
}
else {
printf("International Currency Symbol =");
printf("[Not available in this locale]\n");
}
/* Compare International Fractional Digits with CHAR_MAX. */
/* If they are equal, then International Fractional Digits */
/* are not defined in this locale. */
if ((unsigned char) (lconv_ptr->int_frac_digits) != CHAR_MAX) {
printf("International Fractional Digits = %d\n",
lconv_ptr->int_frac_digits);
}
else {
printf("International Fractional Digits =");
printf("[Not available in this locale]\n");
}
}
Running the example program produces the following result:
International Currency Symbol = GBP
International Fractional Digits = 2