619 lines
16 KiB
Groff
619 lines
16 KiB
Groff
.\" Copyright (c) 1990, 1991, 1993
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.\" The Regents of the University of California. All rights reserved.
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.\"
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.\" This code is derived from software contributed to Berkeley by
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.\" Chris Torek and the American National Standards Committee X3,
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.\" on Information Processing Systems.
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.\"
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.\" Redistribution and use in source and binary forms, with or without
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.\" modification, are permitted provided that the following conditions
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.\" are met:
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.\" 1. Redistributions of source code must retain the above copyright
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.\" notice, this list of conditions and the following disclaimer.
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.\" 2. Redistributions in binary form must reproduce the above copyright
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.\" notice, this list of conditions and the following disclaimer in the
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.\" documentation and/or other materials provided with the distribution.
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.\" 3. All advertising materials mentioning features or use of this software
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.\" must display the following acknowledgement:
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.\" This product includes software developed by the University of
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.\" California, Berkeley and its contributors.
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.\" 4. Neither the name of the University nor the names of its contributors
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.\" may be used to endorse or promote products derived from this software
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.\" without specific prior written permission.
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.\"
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.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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.\" SUCH DAMAGE.
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.\"
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.\" @(#)printf.3 8.1 (Berkeley) 6/4/93
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.\" FreeBSD: src/lib/libc/stdio/printf.3,v 1.47 2002/09/06 11:23:55 tjr Exp
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.\" $FreeBSD$
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.\"
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.Dd September 18, 2002
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.Dt WPRINTF 3
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.Os
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.Sh NAME
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.Nm wprintf , fwprintf , swprintf ,
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.Nm vwprintf , vfwprintf , vswprintf
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.Nd formatted wide character output conversion
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.Sh LIBRARY
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.Lb libc
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.Sh SYNOPSIS
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.In stdio.h
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.In wchar.h
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.Ft int
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.Fn fwprintf "FILE * restrict stream" "const wchar_t * restrict format" ...
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.Ft int
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|
.Fn swprintf "wchar_t * restrict ws" "size_t n" "const wchar_t * restrict format" ...
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|
.Ft int
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|
.Fn wprintf "const wchar_t * restrict format" ...
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|
.In stdarg.h
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|
.Ft int
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|
.Fn vfwprintf "FILE * restrict stream" "const wchar_t * restrict" "va_list ap"
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|
.Ft int
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|
.Fn vswprintf "wchar_t * restrict ws" "size_t n" "const wchar_t *restrict format" "va_list ap"
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.Ft int
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.Fn vwprintf "const wchar_t * restrict format" "va_list ap"
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.Sh DESCRIPTION
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|
The
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.Fn wprintf
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|
family of functions produces output according to a
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|
.Fa format
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|
as described below.
|
|
The
|
|
.Fn wprintf
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|
and
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|
.Fn vwprintf
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|
functions
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|
write output to
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|
.Pa stdout ,
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|
the standard output stream;
|
|
.Fn fwprintf
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|
and
|
|
.Fn vfwprintf
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|
write output to the given output
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|
.Fa stream ;
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|
.Fn swprintf ,
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|
.Fn vswprintf ,
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|
and
|
|
.Fn vsnprintf
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|
write to the wide character string
|
|
.Fa ws .
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|
.Pp
|
|
These functions write the output under the control of a
|
|
.Fa format
|
|
string that specifies how subsequent arguments
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|
(or arguments accessed via the variable-length argument facilities of
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|
.Xr stdarg 3 )
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|
are converted for output.
|
|
.Pp
|
|
These functions return the number of characters printed
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|
(not including the trailing
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|
.Ql \e0
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|
used to end output to strings).
|
|
.Pp
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|
The
|
|
.Fn swprintf
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|
and
|
|
.Fn vswprintf
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|
functions will fail if
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|
.Fa n
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|
or more wide characters were requested to be written,
|
|
.Pp
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|
The format string is composed of zero or more directives:
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|
ordinary
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|
characters (not
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|
.Cm % ) ,
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|
which are copied unchanged to the output stream;
|
|
and conversion specifications, each of which results
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|
in fetching zero or more subsequent arguments.
|
|
Each conversion specification is introduced by
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|
the
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|
.Cm %
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|
character.
|
|
The arguments must correspond properly (after type promotion)
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|
with the conversion specifier.
|
|
After the
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|
.Cm % ,
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|
the following appear in sequence:
|
|
.Bl -bullet
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|
.It
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|
An optional field, consisting of a decimal digit string followed by a
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|
.Cm $ ,
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|
specifying the next argument to access.
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|
If this field is not provided, the argument following the last
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|
argument accessed will be used.
|
|
Arguments are numbered starting at
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|
.Cm 1 .
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|
If unaccessed arguments in the format string are interspersed with ones that
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|
are accessed the results will be indeterminate.
|
|
.It
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|
Zero or more of the following flags:
|
|
.Bl -tag -width ".So \ Sc (space)"
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|
.It Sq Cm #
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|
The value should be converted to an
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|
.Dq alternate form .
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|
For
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|
.Cm c , d , i , n , p , s ,
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|
and
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|
.Cm u
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|
conversions, this option has no effect.
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|
For
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|
.Cm o
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|
conversions, the precision of the number is increased to force the first
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|
character of the output string to a zero (except if a zero value is printed
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|
with an explicit precision of zero).
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|
For
|
|
.Cm x
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|
and
|
|
.Cm X
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|
conversions, a non-zero result has the string
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|
.Ql 0x
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|
(or
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|
.Ql 0X
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|
for
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|
.Cm X
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|
conversions) prepended to it.
|
|
For
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|
.Cm a , A , e , E , f , F , g ,
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|
and
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|
.Cm G
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|
conversions, the result will always contain a decimal point, even if no
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|
digits follow it (normally, a decimal point appears in the results of
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|
those conversions only if a digit follows).
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|
For
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|
.Cm g
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|
and
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|
.Cm G
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|
conversions, trailing zeros are not removed from the result as they
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|
would otherwise be.
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|
.It So Cm 0 Sc (zero)
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|
Zero padding.
|
|
For all conversions except
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|
.Cm n ,
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|
the converted value is padded on the left with zeros rather than blanks.
|
|
If a precision is given with a numeric conversion
|
|
.Cm ( d , i , o , u , i , x ,
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|
and
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|
.Cm X ) ,
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|
the
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|
.Cm 0
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|
flag is ignored.
|
|
.It Sq Cm \-
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|
A negative field width flag;
|
|
the converted value is to be left adjusted on the field boundary.
|
|
Except for
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|
.Cm n
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|
conversions, the converted value is padded on the right with blanks,
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|
rather than on the left with blanks or zeros.
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|
A
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|
.Cm \-
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|
overrides a
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|
.Cm 0
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|
if both are given.
|
|
.It So "\ " Sc (space)
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|
A blank should be left before a positive number
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|
produced by a signed conversion
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|
.Cm ( a , A , d , e , E , f , F , g , G ,
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|
or
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|
.Cm i ) .
|
|
.It Sq Cm +
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|
A sign must always be placed before a
|
|
number produced by a signed conversion.
|
|
A
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|
.Cm +
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|
overrides a space if both are used.
|
|
.It Sq Cm '
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|
Decimal conversions
|
|
.Cm ( d , u ,
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|
or
|
|
.Cm i )
|
|
or the integral portion of a floating point conversion
|
|
.Cm ( f
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|
or
|
|
.Cm F )
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|
should be grouped and separated by thousands using
|
|
the non-monetary separator returned by
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|
.Xr localeconv 3 .
|
|
.El
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|
.It
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|
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.
|
|
.It
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|
An optional precision, in the form of a period
|
|
.Cm \&.
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|
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
|
|
.Cm d , i , o , u , x ,
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|
and
|
|
.Cm X
|
|
conversions, the number of digits to appear after the decimal-point for
|
|
.Cm a , A , e , E , f ,
|
|
and
|
|
.Cm F
|
|
conversions, the maximum number of significant digits for
|
|
.Cm g
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|
and
|
|
.Cm G
|
|
conversions, or the maximum number of characters to be printed from a
|
|
string for
|
|
.Cm s
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|
conversions.
|
|
.It
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|
An optional length modifier, that specifies the size of the argument.
|
|
The following length modifiers are valid for the
|
|
.Cm d , i , n , o , u , x ,
|
|
or
|
|
.Cm X
|
|
conversion:
|
|
.Bl -column ".Cm q Em (deprecated)" ".Vt signed char" ".Vt unsigned long long" ".Vt long long *"
|
|
.It Sy Modifier Ta Cm d , i Ta Cm o , u , x , X Ta Cm n
|
|
.It Cm hh Ta Vt "signed char" Ta Vt "unsigned char" Ta Vt "signed char *"
|
|
.It Cm h Ta Vt short Ta Vt "unsigned short" Ta Vt "short *"
|
|
.It Cm l No (ell) Ta Vt long Ta Vt "unsigned long" Ta Vt "long *"
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|
.It Cm ll No (ell ell) Ta Vt "long long" Ta Vt "unsigned long long" Ta Vt "long long *"
|
|
.It Cm j Ta Vt intmax_t Ta Vt uintmax_t Ta Vt "intmax_t *"
|
|
.It Cm t Ta Vt ptrdiff_t Ta (see note) Ta Vt "ptrdiff_t *"
|
|
.It Cm z Ta (see note) Ta Vt size_t Ta (see note)
|
|
.It Cm q Em (deprecated) Ta Vt quad_t Ta Vt u_quad_t Ta Vt "quad_t *"
|
|
.El
|
|
.Pp
|
|
Note:
|
|
the
|
|
.Cm t
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|
modifier, when applied to a
|
|
.Cm o , u , x ,
|
|
or
|
|
.Cm X
|
|
conversion, indicates that the argument is of an unsigned type
|
|
equivalent in size to a
|
|
.Vt ptrdiff_t .
|
|
The
|
|
.Cm z
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|
modifier, when applied to a
|
|
.Cm d
|
|
or
|
|
.Cm i
|
|
conversion, indicates that the argument is of a signed type equivalent in
|
|
size to a
|
|
.Vt size_t .
|
|
Similarly, when applied to an
|
|
.Cm n
|
|
conversion, it indicates that the argument is a pointer to a signed type
|
|
equivalent in size to a
|
|
.Vt size_t .
|
|
.Pp
|
|
The following length modifier is valid for the
|
|
.Cm a , A , e , E , f , F , g ,
|
|
or
|
|
.Cm G
|
|
conversion:
|
|
.Bl -column ".Sy Modifier" ".Cm a , A , e , E , f , F , g , G"
|
|
.It Sy Modifier Ta Cm a , A , e , E , f , F , g , G
|
|
.It Cm L Ta Vt "long double"
|
|
.El
|
|
.Pp
|
|
The following length modifier is valid for the
|
|
.Cm c
|
|
or
|
|
.Cm s
|
|
conversion:
|
|
.Bl -column ".Sy Modifier" ".Vt wint_t" ".Vt wchar_t *"
|
|
.It Sy Modifier Ta Cm c Ta Cm s
|
|
.It Cm l No (ell) Ta Vt wint_t Ta Vt "wchar_t *"
|
|
.El
|
|
.It
|
|
A character that specifies the type of conversion to be applied.
|
|
.El
|
|
.Pp
|
|
A field width or precision, or both, may be indicated by
|
|
an asterisk
|
|
.Ql *
|
|
or an asterisk followed by one or more decimal digits and a
|
|
.Ql $
|
|
instead of a
|
|
digit string.
|
|
In this case, an
|
|
.Vt 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
|
|
.Pq Li nn$
|
|
and non-positional arguments, the results are undefined.
|
|
.Pp
|
|
The conversion specifiers and their meanings are:
|
|
.Bl -tag -width ".Cm diouxX"
|
|
.It Cm diouxX
|
|
The
|
|
.Vt int
|
|
(or appropriate variant) argument is converted to signed decimal
|
|
.Cm ( d
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|
and
|
|
.Cm i ) ,
|
|
unsigned octal
|
|
.Pq Cm o ,
|
|
unsigned decimal
|
|
.Pq Cm u ,
|
|
or unsigned hexadecimal
|
|
.Cm ( x
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|
and
|
|
.Cm X )
|
|
notation.
|
|
The letters
|
|
.Dq Li abcdef
|
|
are used for
|
|
.Cm x
|
|
conversions; the letters
|
|
.Dq Li ABCDEF
|
|
are used for
|
|
.Cm 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.
|
|
.It Cm DOU
|
|
The
|
|
.Vt "long int"
|
|
argument is converted to signed decimal, unsigned octal, or unsigned
|
|
decimal, as if the format had been
|
|
.Cm ld , lo ,
|
|
or
|
|
.Cm lu
|
|
respectively.
|
|
These conversion characters are deprecated, and will eventually disappear.
|
|
.It Cm eE
|
|
The
|
|
.Vt double
|
|
argument is rounded and converted in the style
|
|
.Sm off
|
|
.Oo \- Oc Ar d Li \&. Ar ddd Li e \\*[Pm] Ar dd
|
|
.Sm on
|
|
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
|
|
.Cm E
|
|
conversion uses the letter
|
|
.Ql E
|
|
(rather than
|
|
.Ql e )
|
|
to introduce the exponent.
|
|
The exponent always contains at least two digits; if the value is zero,
|
|
the exponent is 00.
|
|
.Pp
|
|
For
|
|
.Cm a , A , e , E , f , F , g ,
|
|
and
|
|
.Cm G
|
|
conversions, positive and negative infinity are represented as
|
|
.Li inf
|
|
and
|
|
.Li -inf
|
|
respectively when using the lowercase conversion character, and
|
|
.Li INF
|
|
and
|
|
.Li -INF
|
|
respectively when using the uppercase conversion character.
|
|
Similarly, NaN is represented as
|
|
.Li nan
|
|
when using the lowercase conversion, and
|
|
.Li NAN
|
|
when using the uppercase conversion.
|
|
.It Cm fF
|
|
The
|
|
.Vt double
|
|
argument is rounded and converted to decimal notation in the style
|
|
.Sm off
|
|
.Oo \- Oc Ar ddd Li \&. Ar ddd ,
|
|
.Sm on
|
|
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.
|
|
.It Cm gG
|
|
The
|
|
.Vt double
|
|
argument is converted in style
|
|
.Cm f
|
|
or
|
|
.Cm e
|
|
(or
|
|
.Cm F
|
|
or
|
|
.Cm E
|
|
for
|
|
.Cm 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
|
|
.Cm 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.
|
|
.It Cm aA
|
|
The
|
|
.Vt double
|
|
argument is converted to hexadecimal notation in the style
|
|
.Sm off
|
|
.Oo \- Oc Li 0x Ar h Li \&. Ar hhhp Oo \\*[Pm] Oc Ar d ,
|
|
.Sm on
|
|
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
|
|
.Sm off
|
|
.Oo \- Oc Li 0x Ar h Li \&. Ar hhh
|
|
.Sm on
|
|
portion represents exactly the mantissa; only denormalized
|
|
mantissas have a zero value to the left of the hexadecimal
|
|
point.
|
|
The
|
|
.Cm p
|
|
is a literal character
|
|
.Ql 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
|
|
.Cm A
|
|
conversion uses the prefix
|
|
.Dq Li 0X
|
|
(rather than
|
|
.Dq Li 0x ) ,
|
|
the letters
|
|
.Dq Li ABCDEF
|
|
(rather than
|
|
.Dq Li abcdef )
|
|
to represent the hex digits, and the letter
|
|
.Ql P
|
|
(rather than
|
|
.Ql p )
|
|
to separate the mantissa and exponent.
|
|
.It Cm C
|
|
Treated as
|
|
.Cm c
|
|
with the
|
|
.Cm l
|
|
(ell) modifier.
|
|
.It Cm c
|
|
The
|
|
.Vt int
|
|
argument is converted to an
|
|
.Vt "unsigned char" ,
|
|
then to a
|
|
.Vt wchar_t
|
|
as if by
|
|
.Xr btowc 3 ,
|
|
and the resulting character is written.
|
|
.Pp
|
|
If the
|
|
.Cm l
|
|
(ell) modifier is used, the
|
|
.Vt wint_t
|
|
argument is converted to a
|
|
.Vt wchar_t
|
|
and written.
|
|
.It Cm S
|
|
Treated as
|
|
.Cm s
|
|
with the
|
|
.Cm l
|
|
(ell) modifier.
|
|
.It Cm s
|
|
The
|
|
.Vt "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
|
|
.Dv 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
|
|
.Dv NUL
|
|
character.
|
|
.Pp
|
|
If the
|
|
.Cm l
|
|
(ell) modifier is used, the
|
|
.Vt "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
|
|
.Dv 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
|
|
.Dv NUL
|
|
character.
|
|
.It Cm p
|
|
The
|
|
.Vt "void *"
|
|
pointer argument is printed in hexadecimal (as if by
|
|
.Ql %#x
|
|
or
|
|
.Ql %#lx ) .
|
|
.It Cm n
|
|
The number of characters written so far is stored into the
|
|
integer indicated by the
|
|
.Vt "int *"
|
|
(or variant) pointer argument.
|
|
No argument is converted.
|
|
.It Cm %
|
|
A
|
|
.Ql %
|
|
is written.
|
|
No argument is converted.
|
|
The complete conversion specification
|
|
is
|
|
.Ql %% .
|
|
.El
|
|
.Pp
|
|
The decimal point
|
|
character is defined in the program's locale (category
|
|
.Dv LC_NUMERIC ) .
|
|
.Pp
|
|
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.
|
|
.Sh SECURITY CONSIDERATIONS
|
|
Refer to
|
|
.Xr printf 3 .
|
|
.Sh SEE ALSO
|
|
.Xr printf 3 ,
|
|
.Xr setlocale 3
|
|
.Sh STANDARDS
|
|
Subject to the caveats noted in the
|
|
.Sx BUGS
|
|
section
|
|
of
|
|
.Xr printf 3 ,
|
|
the
|
|
.Fn wprintf ,
|
|
.Fn fwprintf ,
|
|
.Fn swprintf ,
|
|
.Fn vwprintf ,
|
|
.Fn vfwprintf
|
|
and
|
|
.Fn vswprintf
|
|
functions
|
|
conform to
|
|
.St -isoC-99 .
|