| WPRINTF(3) | Library Functions Manual | WPRINTF(3) |
int
fwprintf(FILE * restrict stream, const wchar_t * restrict format, ...);
int
swprintf(wchar_t * restrict ws, size_t n, const wchar_t * restrict format, ...);
int
wprintf(const wchar_t * restrict format, ...);
#include <stdarg.h>
int
vfwprintf(FILE * restrict stream, const wchar_t * restrict, va_list ap);
int
vswprintf(wchar_t * restrict ws, size_t n, const wchar_t *restrict format, va_list ap);
int
vwprintf(const wchar_t * restrict format, va_list ap);
These functions write the output under the control of a format string that specifies how subsequent arguments (or arguments accessed via the variable-length argument facilities of stdarg(3)) are converted for output.
The swprintf() and vswprintf() functions will fail if n or more wide characters were requested to be written,
The format string is composed of zero or more directives: ordinary characters (not %), which are copied unchanged to the output stream; and conversion specifications, each of which results in fetching zero or more subsequent arguments. Each conversion specification is introduced by the % character. The arguments must correspond properly (after type promotion) with the conversion specifier. After the %, the following appear in sequence:
0x’ (or ‘0X’ for X conversions) prepended to it. For a, A, e, E, f, F, g, and G conversions, the result will always contain a decimal point, even if no digits follow it (normally, a decimal point appears in the results of those conversions only if a digit follows). For g and G conversions, trailing zeros are not removed from the result as they would otherwise be.| Modifier | d, i | o, u, x, X | n |
| hh | signed char | unsigned char | signed char * |
| h | short | unsigned short | short * |
| l (ell) | long | unsigned long | long * |
| ll (ell ell) | long long | unsigned long long | long long * |
| j | intmax_t | uintmax_t | intmax_t * |
| t | ptrdiff_t | (see note) | ptrdiff_t * |
| z | (see note) | size_t | (see note) |
| q (deprecated) | quad_t | u_quad_t | quad_t * |
Note: the t modifier, when applied to a o, u, x, or X conversion, indicates that the argument is of an unsigned type equivalent in size to a ptrdiff_t. The z modifier, when applied to a d or i conversion, indicates that the argument is of a signed type equivalent in size to a size_t. Similarly, when applied to an n conversion, it indicates that the argument is a pointer to a signed type equivalent in size to a size_t.
The following length modifier is valid for the a, A, e, E, f, F, g, or G conversion:
| Modifier | a, A, e, E, f, F, g, G |
| L | long double |
The following length modifier is valid for the c or s conversion:
| Modifier | c | s |
| l (ell) | wint_t | wchar_t * |
A field width or precision, or both, may be indicated by an asterisk ‘*’ or an asterisk followed by one or more decimal digits and a ‘$’ instead of a digit string. In this case, an int argument supplies the field width or precision. A negative field width is treated as a left adjustment flag followed by a positive field width; a negative precision is treated as though it were missing. If a single format directive mixes positional (nn$) and non-positional arguments, the results are undefined.
The conversion specifiers and their meanings are:
abcdef” are used for x conversions; the letters “ABCDEF” are used for X conversions. The precision, if any, gives the minimum number of digits that must appear; if the converted value requires fewer digits, it is padded on the left with zeros..ddde±dd where there is one digit before the decimal-point character and the number of digits after it is equal to the precision; if the precision is missing, it is taken as 6; if the precision is zero, no decimal-point character appears. An E conversion uses the letter ‘E’ (rather than ‘e’) to introduce the exponent. The exponent always contains at least two digits; if the value is zero, the exponent is 00.
For a, A, e, E, f, F, g, and G conversions, positive and negative infinity are represented as inf and -inf respectively when using the lowercase conversion character, and INF and -INF respectively when using the uppercase conversion character. Similarly, NaN is represented as nan when using the lowercase conversion, and NAN when using the uppercase conversion.
.ddd, where the number of digits after the decimal-point character is equal to the precision specification. If the precision is missing, it is taken as 6; if the precision is explicitly zero, no decimal-point character appears. If a decimal point appears, at least one digit appears before it.0xh.hhhp[±]d, where the number of digits after the hexadecimal-point character is equal to the precision specification. If the precision is missing, it is taken as enough to exactly represent the floating-point number; if the precision is explicitly zero, no hexadecimal-point character appears. This is an exact conversion of the mantissa+exponent internal floating point representation; the [-]0xh.hhh portion represents exactly the mantissa; only denormalized mantissas have a zero value to the left of the hexadecimal point. The p is a literal character ‘p’; the exponent is preceded by a positive or negative sign and is represented in decimal, using only enough characters to represent the exponent. The A conversion uses the prefix “0X” (rather than “0x”), the letters “ABCDEF” (rather than “abcdef”) to represent the hex digits, and the letter ‘P’ (rather than ‘p’) to separate the mantissa and exponent.If the l (ell) modifier is used, the wint_t argument is converted to a wchar_t and written.
If the l (ell) modifier is used, the wchar_t * argument is expected to be a pointer to an array of wide characters (pointer to a wide string). Each wide character in the string is written. Wide characters from the array are written up to (but not including) a terminating wide NUL character; if a precision is specified, no more than the number specified are written (including shift sequences). If a precision is given, no null character need be present; if the precision is not specified, or is greater than the number of characters in the string, the array must contain a terminating wide NUL character.
%#x’ or ‘%#lx’).%’ is written. No argument is converted. The complete conversion specification is ‘%%’.The decimal point character is defined in the program's locale (category LC_NUMERIC).
In no case does a non-existent or small field width cause truncation of a numeric field; if the result of a conversion is wider than the field width, the field is expanded to contain the conversion result.
\0’ used to end output to strings).| April 30, 2010 | NetBSD 7.0 |