Standard C Library Functions fwprintf(3C)
NAME
fwprintf, wprintf, swprintf - print formatted wide-character
output
SYNOPSIS
#include
#include
int fwprintf(FILE *restrict stream, const wchart *restrict format,
...);
int wprintf(const wchart *restrict format, ...);
int swprintf(wchart *restrict s, sizet n, const wchart *restrict format,
...);
DESCRIPTION
The fwprintf() function places output on the named output
stream. The wprintf() function places output on the standard
output stream stdout. The swprintf() function places output
followed by the null wide-character in consecutive wide-
characters starting at *s; no more than n wide-characters
are written, including a terminating null wide-character,
which is always added (unless n is zero).
Each of these functions converts, formats and prints its
arguments under control of the format wide-character string.
The format is composed of zero or more directives: ordinary
wide-characters, which are simply copied to the output
stream and conversion specifications, each of which results
in the fetching of zero or more arguments. The results are
undefined if there are insufficient arguments for the for-
mat. If the format is exhausted while arguments remain, the
excess arguments are evaluated but are otherwise ignored.
Conversions can be applied to the nth argument after the
format in the argument list, rather than to the next unused
argument. In this case, the conversion wide-character % (see
below) is replaced by the sequence %n$, where n is a decimal
integer in the range [1, NLARGMAX], giving the position of
the argument in the argument list. This feature provides for
the definition of format wide-character strings that select
arguments in an order appropriate to specific languages (see
the EXAMPLES section).
SunOS 5.11 Last change: 1 Nov 2003 1
Standard C Library Functions fwprintf(3C)
In format wide-character strings containing the %n$ form of
conversion specifications, numbered arguments in the argu-
ment list can be referenced from the format wide-character
string as many times as required.
In format wide-character strings containing the % form of
conversion specifications, each argument in the argument
list is used exactly once.
All forms of the fwprintf() functions allow for the inser-
tion of a language-dependent radix character in the output
string, output as a wide-character value. The radix charac-
ter is defined in the program's locale (category
LCNUMERIC). In the POSIX locale, or in a locale where the
radix character is not defined, the radix character defaults
to a period (.).
Each conversion specification is introduced by the % wide-
character or by the wide-character sequence %n$, after which
the following appear in sequence:
o Zero or more flags (in any order), which modify the
meaning of the conversion specification.
o An optional minimum field width. If the converted
value has fewer wide-characters than the field
width, it will be padded with spaces by default on
the left; it will be padded on the right, if the
left-adjustment flag (-), described below, is given
to the field width. The field width takes the form
of an asterisk (*), described below, or a decimal
integer.
o An optional precision that gives the minimum number
of digits to appear for the d, i, o, u, x, and X
conversions; the number of digits to appear after
the radix character for the a, A, e, E, f, and F
conversions; the maximum number of significant
digits for the g and G conversions; or the maximum
number of wide-characters to be printed from a
string in s conversions. The precision takes the
form of a period (.) followed by either an asterisk
(*), described below, or an optional decimal digit
string, where a null digit string is treated as 0.
If a precision appears with any other conversion
wide-character, the behavior is undefined.
o An optional length modifier that specifies the size
of the argument.
SunOS 5.11 Last change: 1 Nov 2003 2
Standard C Library Functions fwprintf(3C)
o A conversion specifier wide character that indi-
cates the type of conversion to be applied.
A field width, or precision, or both, may be indicated by an
asterisk (*). In this case an argument of type int supplies
the field width or precision. Arguments specifying field
width, or precision, or both must appear in that order
before the argument, if any, to be converted. A negative
field width is taken as a - flag followed by a positive
field width. A negative precision is taken as if the preci-
sion were omitted. In format wide-character strings contain-
ing the %n$ form of a conversion specification, a field
width or precision may be indicated by the sequence *m$,
where m is a decimal integer in the range [1, NLARGMAX]
giving the position in the argument list (after the format
argument) of an integer argument containing the field width
or precision, for example:
wprintf(L"%1$d:%2$.*3$d:%4$.*3$d\n", hour, min, precision, sec);
The format can contain either numbered argument specifica-
tions (that is, %n$ and *m$), or unnumbered argument specif-
ications (that is, % and *), but normally not both. The only
exception to this is that %% can be mixed with the %n$ form.
The results of mixing numbered and unnumbered argument
specifications in a format wide-character string are unde-
fined. When numbered argument specifications are used,
specifying the Nth argument requires that all the leading
arguments, from the first to the (N-1)th, are specified in
the format wide-character string.
The flag wide-characters and their meanings are:
' The integer portion of the result of a decimal
conversion (%i, %d, %u, %f, %F, %g, or %G) will be
formatted with thousands' grouping wide-characters.
For other conversions the behavior is undefined.
The non-monetary grouping wide-character is used.
- The result of the conversion will be left-justified
within the field. The conversion will be right-
justified if this flag is not specified.
] The result of a signed conversion will always begin
with a sign (] or -). The conversion will begin
with a sign only when a negative value is converted
SunOS 5.11 Last change: 1 Nov 2003 3
Standard C Library Functions fwprintf(3C)
if this flag is not specified.
space If the first wide-character of a signed conversion
is not a sign or if a signed conversion results in
no wide-characters, a space will be prefixed to the
result. This means that if the space and ] flags
both appear, the space flag will be ignored.
# This flag specifies that the value is to be con-
verted to an alternative form. For o conversion, it
increases the precision (if necessary) to force the
first digit of the result to be 0. For x or X
conversions, a non-zero result will have 0x (or 0X)
prefixed to it. For a, A, e, E, f, F, g, or G
conversions, the result will always contain a radix
character, even if no digits follow it. Without
this flag, a radix character appears in the result
of these conversions only if a digit follows it.
For g and G conversions, trailing zeros will not
be removed from the result as they normally are.
For other conversions, the behavior is undefined.
0 For d, i, o, u, x, X, a, A, e, E, f, F, g, and G
conversions, leading zeros (following any indica-
tion of sign or base) are used to pad to the field
width; no space padding is performed. If the 0 and
- flags both appear, the 0 flag will be ignored.
For d, i, o, u, x, and X conversions, if a preci-
sion is specified, the 0 flag will be ignored. If
the 0 and ' flags both appear, the grouping wide-
characters are inserted before zero padding. For
other conversions, the behavior is undefined.
The length modifiers and their meanings:
hh Specifies that a following d, i, o, u, x, or
X conversion specifier applies to a signed
char or unsigned char argument (the argument
will have been promoted according to the
integer promotions, but its value shall be
converted to signed char or unsigned char
before printing); or that a following n
conversion specifier applies to a pointer to
a signed char argument.
SunOS 5.11 Last change: 1 Nov 2003 4
Standard C Library Functions fwprintf(3C)
h Specifies that a following d, i, o, u, x, or
X conversion specifier applies to a short or
unsigned short argument (the argument will
have been promoted according to the integer
promotions, but its value shall be converted
to short or unsigned short before printing);
or that a following n conversion specifier
applies to a pointer to a short argument.
l (ell) Specifies that a following d, i, o, u, x, or
X conversion specifier applies to a long or
unsigned long argument; that a following n
conversion specifier applies to a pointer to
a long argument; that a following c conver-
sion specifier applies to a wintt argument;
that a following s conversion specifier
applies to a pointer to a wchart argument;
or has no effect on a following a, A, e, E,
f, F, g, or G conversion specifier.
ll (ell-ell) Specifies that a following d, i, o, u, x, or
X conversion specifier applies to a long
long or unsigned long long argument; or that
a following n conversion specifier applies
to a pointer to a long long argument.
j Specifies that a following d, i, o, u, x, or
X conversion specifier applies to an
intmaxt or uintmaxt argument; or that a
following n conversion specifier applies to
a pointer to an intmaxt argument.
z Specifies that a following d, i, o, u, x, or
X conversion specifier applies to a sizet
or the corresponding signed integer type
argument; or that a following n conversion
specifier applies to a pointer to a signed
integer type corresponding to sizet argu-
ment.
t Specifies that a following d, i, o, u, x, or
X conversion specifier applies to a
ptrdifft or the corresponding unsigned type
argument; or that a following n conversion
specifier applies to a pointer to a
ptrdifft argument.
SunOS 5.11 Last change: 1 Nov 2003 5
Standard C Library Functions fwprintf(3C)
L Specifies that a following a, A, e, E, f, F,
g, or G conversion specifier applies to a
long double argument.
If a length modifier appears with any conversion specifier
other than as specified above, the behavior is undefined.
The conversion wide-characters and their meanings are:
d, i The int argument is converted to a signed decimal in
the style [-]dddd. The precision specifies the
minimum number of digits to appear; if the value
being converted can be represented in fewer digits,
it will be expanded with leading zeros. The default
precision is 1. The result of converting 0 with an
explicit precision of 0 is no wide-characters.
o The unsigned int argument is converted to unsigned
octal format in the style dddd. The precision speci-
fies the minimum number of digits to appear; if the
value being converted can be represented in fewer
digits, it will be expanded with leading zeros. The
default precision is 1. The result of converting 0
with an explicit precision of 0 is no wide-
characters.
u The unsigned int argument is converted to unsigned
decimal format in the style dddd. The precision
specifies the minimum number of digits to appear; if
the value being converted can be represented in
fewer digits, it will be expanded with leading
zeros. The default precision is 1. The result of
converting 0 with an explicit precision of 0 is no
wide-characters.
x The unsigned int argument is converted to unsigned
hexadecimal format in the style dddd; the letters
abcdef are used. The precision specifies the minimum
number of digits to appear; if the value being con-
verted can be represented in fewer digits, it will
be expanded with leading zeros. The default preci-
sion is 1. The result of converting 0 with an expli-
cit precision of 0 is no wide-characters.
SunOS 5.11 Last change: 1 Nov 2003 6
Standard C Library Functions fwprintf(3C)
X Behaves the same as the x conversion wide-character
except that letters "ABCDEF" are used instead of
"abcdef".
f, F The double argument is converted to decimal notation
in the style [-]ddd.ddd, where the number of digits
after the radix character (see setlocale(3C)) is
equal to the precision specification. If the preci-
sion is missing it is taken as 6; if the precision
is explicitly 0 and the # flag is not specified, no
radix character appears. If a radix character
appears, at least 1 digit appears before it. The
converted value is rounded to fit the specified out-
put format according to the prevailing floating
point rounding direction mode. If the conversion is
not exact, an inexact exception is raised.
For the f specifier, a double argument representing
an infinity or NaN is converted in the style of the
e conversion specifier, except that for an infinite
argument, "infinity" or "Infinity" is printed when
the precision is at least 8 and "inf" or "Inf" is
printed otherwise.
For the F specifier, a double argument representing
an infinity or NaN is converted in the SUSv3 style
of the E conversion specifier, except that for an
infinite argument, "INFINITY" is printed when the
precision is at least 8 and or "INF" is printed oth-
erwise.
e, E The double argument is converted in the style
[-]d.ddde]dd, where there is one digit before the
radix character (which is non-zero if the argument
is non-zero) 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 0 and no #
flag is present, no radix character appears. The
converted value is rounded to fit the specified out-
put format according to the prevailing floating
point rounding direction mode. If the conversion is
not exact, an inexact exception is raised. The E
conversion wide-character will produce a number with
E instead of e introducing the exponent. The
exponent always contains at least two digits. If the
value is 0, the exponent is 0.
Infinity and NaN values are handled in one of the
following ways:
SunOS 5.11 Last change: 1 Nov 2003 7
Standard C Library Functions fwprintf(3C)
SUSv3 For the e specifier, a double argument
representing an infinity is printed as
"[-]infinity", when the precision for the
conversion is at least 7 and as "[-]inf"
otherwise. A double argument representing
a NaN is printed as "[-]nan". For the E
specifier, "INF", "INFINITY", and "NAN"
are printed instead of "inf", "infinity",
and "nan", respectively. Printing of the
sign follows the rules described above.
Default A double argument representing an infin-
ity is printed as "[-]Infinity", when the
precision for the conversion is at least
7 and as "[-]Inf" otherwise. A double
argument representing a NaN is printed as
"[-]NaN". Printing of the sign follows
the rules described above.
g, G The double argument is converted in the style f or e
(or in the style E in the case of a G conversion
wide-character), with the precision specifying the
number of significant digits. If an explicit preci-
sion is 0, it is taken as 1. The style used depends
on the value converted; style e (or E ) will be used
only if the exponent resulting from such a conver-
sion is less than -4 or greater than or equal to the
precision. Trailing zeros are removed from the frac-
tional portion of the result; a radix character
appears only if it is followed by a digit.
A double argument representing an infinity or NaN is
converted in the style of the e or E conversion
specifier, except that for an infinite argument,
"infinity", "INFINITY", or "Infinity" is printed
when the precision is at least 8 and "inf", "INF",
or "Inf" is printed otherwise.
a, A A double argument representing a floating-point
number is converted in the style "[-]0xh.hhhhp]d",
where the single hexadecimal digit preceding the
radix point is 0 if the value converted is zero and
1 otherwise and the number of hexadecimal digits
after it are equal to the precision; if the preci-
sion is missing, the number of digits printed after
the radix point is 13 for the conversion of a double
value, 16 for the conversion of a long double value
on x86, and 28 for the conversion of a long double
SunOS 5.11 Last change: 1 Nov 2003 8
Standard C Library Functions fwprintf(3C)
value on SPARC; if the precision is zero and the '#'
flag is not specified, no decimal-point wide charac-
ter appears. The letters "abcdef" are used for a
conversion and the letters "ABCDEF" for A conver-
sion. The A conversion specifier produces a number
with 'X' and 'P' instead of 'x' and 'p'. The
exponent always contains at least one digit, and
only as many more digits as necessary to represent
the decimal exponent of 2. If the value is zero, the
exponent is zero.
The converted valueis rounded to fit the specified
output format according to the prevailing floating
point rounding direction mode. If the conversion is
not exact, an inexact exception is raised.
A double argument representing an infinity or NaN is
converted in the SUSv3 style of an e or E conversion
specifier.
c If no l (ell) qualifier is present, the int argument
is converted to a wide-character as if by calling
the btowc(3C) function and the resulting wide-
character is written. Otherwise the wintt argument
is converted to wchart, and written.
s If no l (ell) qualifier is present, the argument
must be a pointer to a character array containing a
character sequence beginning in the initial shift
state. Characters from the array are converted as if
by repeated calls to the mbrtowc(3C) function, with
the conversion state described by an mbstatet
object initialized to zero before the first charac-
ter is converted, and written up to (but not includ-
ing) the terminating null wide-character. If the
precision is specified, no more than that many
wide-characters are written. If the precision is not
specified or is greater than the size of the array,
the array must contain a null wide-character.
If an l (ell) qualifier is present, the argument
must be a pointer to an array of type wchart. Wide
characters from the array are written up to (but not
including) a terminating null wide-character. If no
precision is specified or is greater than the size
of the array, the array must contain a null wide-
character. If a precision is specified, no more than
that many wide-characters are written.
SunOS 5.11 Last change: 1 Nov 2003 9
Standard C Library Functions fwprintf(3C)
p The argument must be a pointer to void. The value of
the pointer is converted to a sequence of printable
wide-characters.
n The argument must be a pointer to an integer into
which is written the number of wide-characters writ-
ten to the output so far by this call to one of the
fwprintf() functions. No argument is converted.
C Same as lc.
S Same as ls.
% Output a % wide-character; no argument is converted.
The entire conversion specification must be %%.
If a conversion specification does not match one of the
above forms, the behavior is undefined.
In no case does a non-existent or small field width cause
truncation of a field; if the result of a conversion is
wider than the field width, the field is simply expanded to
contain the conversion result. Characters generated by
fwprintf() and wprintf() are printed as if fputwc(3C) had
been called.
The stctime and stmtime fields of the file will be marked
for update between the call to a successful execution of
fwprintf() or wprintf() and the next successful completion
of a call to fflush(3C) or fclose(3C) on the same stream or
a call to exit(3C) or abort(3C).
RETURN VALUES
Upon successful completion, these functions return the
number of wide-characters transmitted excluding the ter-
minating null wide-character in the case of swprintf() or a
negative value if an output error was encountered.
If n or more wide characters were requested to be written,
swprintf() returns a negative value.
ERORS
SunOS 5.11 Last change: 1 Nov 2003 10
Standard C Library Functions fwprintf(3C)
For the conditions under which fwprintf() and wprintf() will
fail and may fail, refer to fputwc(3C).
In addition, all forms of fwprintf() may fail if:
EILSEQ A wide-character code that does not correspond to
a valid character has been detected.
EINVAL There are insufficient arguments.
In addition, wprintf() and fwprintf() may fail if:
ENOMEM Insufficient storage space is available.
EXAMPLES
Example 1 Print Language-dependent Date and Time Format.
To print the language-independent date and time format, the
following statement could be used:
wprintf(format, weekday, month, day, hour, min);
For American usage, format could be a pointer to the wide-
character string:
L"%s, %s %d, %d:%.2d\n"
producing the message:
Sunday, July 3, 10:02
whereas for German usage, format could be a pointer to the
wide-character string:
L"%1$s, %3$d. %2$s, %4$d:%5$.2d\n"
SunOS 5.11 Last change: 1 Nov 2003 11
Standard C Library Functions fwprintf(3C)
producing the message:
Sonntag, 3. Juli, 10:02
ATRIBUTES
See attributes(5) for descriptions of the following attri-
butes:
ATRIBUTE TYPE ATRIBUTE VALUE
Interface Stability Standard
MT-Level MT-Safe with exceptions
SEE ALSO
btowc(3C), fputwc(3C), fwscanf(3C), mbrtowc(3C),
setlocale(3C), attributes(5), standards(5)
NOTES
The fwprintf(), wprintf(), and swprintf() functions can be
used safely in multithreaded applications, as long as
setlocale(3C) is not being called to change the locale.
If the j length modifier is used, 32-bit applications that
were compiled using c89 on releases prior to Solaris 10 will
experience undefined behavior.
SunOS 5.11 Last change: 1 Nov 2003 12
|
