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WPRINTF(3)             FreeBSD Library Functions Manual             WPRINTF(3)

NAME
     wprintf, fwprintf, swprintf, vwprintf, vfwprintf, vswprintf - formatted
     wide character output conversion

LIBRARY
     Standard C Library (libc, -lc)

SYNOPSIS
     #include <stdio.h>
     #include <wchar.h>

     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);

DESCRIPTION
     The wprintf() family of functions produces output according to a format
     as described below.  The wprintf() and vwprintf() functions write output
     to stdout, the standard output stream; fwprintf() and vfwprintf() write
     output to the given output stream; swprintf() and vswprintf() write to
     the wide character string ws.

     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.

     These functions return the number of characters printed (not including
     the trailing `\0' used to end output to strings).

     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:

     +o   An optional field, consisting of a decimal digit string followed by a
         $, specifying the next argument to access.  If this field is not
         provided, the argument following the last argument accessed will be
         used.  Arguments are numbered starting at 1.  If unaccessed arguments
         in the format string are interspersed with ones that are accessed the
         results will be indeterminate.

     +o   Zero or more of the following flags:

         `#'               The value should be converted to an ``alternate
                           form''.  For c, d, i, n, p, s, and u conversions,
                           this option has no effect.  For o conversions, the
                           precision of the number is increased to force the
                           first character of the output string to a zero
                           (except if a zero value is printed with an explicit
                           precision of zero).  For x and X conversions, a
                           non-zero result has the string `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.

         `0' (zero)        Zero padding.  For all conversions except n, the
                           converted value is padded on the left with zeros
                           rather than blanks.  If a precision is given with a
                           numeric conversion (d, i, o, u, i, x, and X), the 0
                           flag is ignored.

         `-'               A negative field width flag; the converted value is
                           to be left adjusted on the field boundary.  Except
                           for n conversions, the converted value is padded on
                           the right with blanks, rather than on the left with
                           blanks or zeros.  A - overrides a 0 if both are
                           given.

         ` ' (space)       A blank should be left before a positive number
                           produced by a signed conversion (a, A, d, e, E, f,
                           F, g, G, or i).

         `+'               A sign must always be placed before a number
                           produced by a signed conversion.  A + overrides a
                           space if both are used.

         `''               Decimal conversions (d, u, or i) or the integral
                           portion of a floating point conversion (f or F)
                           should be grouped and separated by thousands using
                           the non-monetary separator returned by
                           localeconv(3).

     +o   An optional decimal digit string specifying a minimum field width.
         If the converted value has fewer characters than the field width, it
         will be padded with spaces on the left (or right, if the left-
         adjustment flag has been given) to fill out the field width.

     +o   An optional precision, in the form of a period . followed by an
         optional digit string.  If the digit string is omitted, the precision
         is taken as zero.  This gives the minimum number of digits to appear
         for d, i, o, u, x, and X conversions, the number of digits to appear
         after the decimal-point for a, A, e, E, f, and F conversions, the
         maximum number of significant digits for g and G conversions, or the
         maximum number of characters to be printed from a string for s
         conversions.

     +o   An optional length modifier, that specifies the size of the argument.
         The following length modifiers are valid for the d, i, n, o, u, x, or
         X conversion:

         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 *

     +o   A character that specifies the type of conversion to be applied.

     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:

     diouxX      The int (or appropriate variant) argument is converted to
                 signed decimal (d and i), unsigned octal (o), unsigned
                 decimal (u), or unsigned hexadecimal (x and X) notation.  The
                 letters ``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.

     DOU         The long int argument is converted to signed decimal,
                 unsigned octal, or unsigned decimal, as if the format had
                 been ld, lo, or lu respectively.  These conversion characters
                 are deprecated, and will eventually disappear.

     eE          The double argument is rounded and converted in the style
                 [-]d.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.

     fF          The double argument is rounded and converted to decimal
                 notation in the style [-]ddd.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.

     gG          The double argument is converted in style f or e (or F or E
                 for G conversions).  The precision specifies the number of
                 significant digits.  If the precision is missing, 6 digits
                 are given; if the precision is zero, it is treated as 1.
                 Style e is used if the exponent from its conversion is less
                 than -4 or greater than or equal to the precision.  Trailing
                 zeros are removed from the fractional part of the result; a
                 decimal point appears only if it is followed by at least one
                 digit.

     aA          The double argument is converted to hexadecimal notation in
                 the style [-]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.

     C           Treated as c with the l (ell) modifier.

     c           The int argument is converted to an unsigned char, then to a
                 wchar_t as if by btowc(3), and the resulting character is
                 written.

                 If the l (ell) modifier is used, the wint_t argument is
                 converted to a wchar_t and written.

     S           Treated as s with the l (ell) modifier.

     s           The char * argument is expected to be a pointer to an array
                 of character type (pointer to a string) containing a
                 multibyte sequence.  Characters from the array are converted
                 to wide characters and written up to (but not including) a
                 terminating NUL character; if a precision is specified, no
                 more than the number specified are written.  If a precision
                 is given, no null character need be present; if the precision
                 is not specified, or is greater than the size of the array,
                 the array must contain a terminating NUL character.

                 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.

     p           The void * pointer argument is printed in hexadecimal (as if
                 by `%#x' or `%#lx').

     n           The number of characters written so far is stored into the
                 integer indicated by the int * (or variant) pointer argument.
                 No argument is converted.

     %           A `%' 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.

SEE ALSO
     btowc(3), fputws(3), printf(3), putwc(3), setlocale(3), wcsrtombs(3),
     wscanf(3)

STANDARDS
     Subject to the caveats noted in the BUGS section of printf(3), the
     wprintf(), fwprintf(), swprintf(), vwprintf(), vfwprintf() and
     vswprintf() functions conform to ISO/IEC 9899:1999 (``ISO C99'').

SECURITY CONSIDERATIONS
     Refer to printf(3).

FreeBSD 11.0-PRERELEASE          July 5, 2003          FreeBSD 11.0-PRERELEASE

NAME | LIBRARY | SYNOPSIS | DESCRIPTION | SEE ALSO | STANDARDS | SECURITY CONSIDERATIONS

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