.\" 2. Redistributions in binary form must reproduce the above copyright
.\" notice, this list of conditions and the following disclaimer in the
.\" documentation and/or other materials provided with the distribution.
-.\" 3. All advertising materials mentioning features or use of this software
-.\" must display the following acknowledgement:
-.\" This product includes software developed by the University of
-.\" California, Berkeley and its contributors.
.\" 4. Neither the name of the University nor the names of its contributors
.\" may be used to endorse or promote products derived from this software
.\" without specific prior written permission.
.\" SUCH DAMAGE.
.\"
.\" @(#)printf.3 8.1 (Berkeley) 6/4/93
-.\" $FreeBSD: src/lib/libc/stdio/printf.3,v 1.58 2004/10/16 16:00:01 stefanf Exp $
+.\" $FreeBSD: src/lib/libc/stdio/printf.3,v 1.64 2009/12/02 07:51:25 brueffer Exp $
.\"
-.Dd October 16, 2004
+.Dd December 2, 2009
.Dt PRINTF 3
.Os
.Sh NAME
-.Nm printf , fprintf , sprintf , snprintf , asprintf ,
-.Nm vprintf , vfprintf, vsprintf , vsnprintf , vasprintf
+.Nm printf , fprintf , sprintf , snprintf , asprintf , dprintf ,
+.Nm vprintf , vfprintf, vsprintf , vsnprintf , vasprintf, vdprintf
.Nd formatted output conversion
.Sh LIBRARY
.Lb libc
.Sh SYNOPSIS
+.Fd "#define _WITH_DPRINTF"
.In stdio.h
.Ft int
.Fn printf "const char * restrict format" ...
.Fn snprintf "char * restrict str" "size_t size" "const char * restrict format" ...
.Ft int
.Fn asprintf "char **ret" "const char *format" ...
+.Ft int
+.Fn dprintf "int fd" "const char * restrict format" ...
.In stdarg.h
.Ft int
.Fn vprintf "const char * restrict format" "va_list ap"
.Fn vsnprintf "char * restrict str" "size_t size" "const char * restrict format" "va_list ap"
.Ft int
.Fn vasprintf "char **ret" "const char *format" "va_list ap"
+.Ft int
+.Fn vdprintf "int fd" "const char * restrict format" "va_list ap"
.Sh DESCRIPTION
The
.Fn printf
.Fn vfprintf
write output to the given output
.Fa stream ;
+.Fn dprintf
+and
+.Fn vdprintf
+write output to the given file descriptor;
.Fn sprintf ,
.Fn snprintf ,
.Fn vsprintf ,
For
.Cm 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).
+character of the output string to a zero.
For
.Cm x
and
Note that there may be multiple valid ways to represent floating-point
numbers in this hexadecimal format.
For example,
-.Li 0x3.24p+0 , 0x6.48p-1
+.Li 0x1.92p+1 , 0x3.24p+0 , 0x6.48p-1 ,
and
.Li 0xc.9p-2
are all equivalent.
-The format chosen depends on the internal representation of the
-number, but the implementation guarantees that the length of the
-mantissa will be minimized.
+.Fx 8.0
+and later always prints finite non-zero numbers using
+.Ql 1
+as the digit before the hexadecimal point.
Zeroes are always represented with a mantissa of 0 (preceded by a
.Ql -
if appropriate) and an exponent of
Always use the proper secure idiom:
.Pp
.Dl "snprintf(buffer, sizeof(buffer), \*q%s\*q, string);"
+.Sh COMPATIBILITY
+Many application writers used the name
+.Va dprintf
+before the
+.Fn dprintf
+function was introduced in
+.St -p1003.1 ,
+so a prototype is not provided by default in order to avoid
+compatibility problems.
+Applications that wish to use the
+.Fn dprintf
+function described herein should either request a strict
+.St -p1003.1-2008
+environment by defining the macro
+.Dv _POSIX_C_SOURCE
+to the value 200809 or greater, or by defining the macro
+.Dv _WITH_DPRINTF ,
+prior to the inclusion of
+.In stdio.h .
+For compatibility with GNU libc, defining either
+.Dv _BSD_SOURCE
+or
+.Dv _GNU_SOURCE
+prior to the inclusion of
+.In stdio.h
+will also make
+.Fn dprintf
+available.
+.Pp
+The conversion formats
+.Cm \&%D , \&%O ,
+and
+.Cm %U
+are not standard and
+are provided only for backward compatibility.
+The effect of padding the
+.Cm %p
+format with zeros (either by the
+.Cm 0
+flag or by specifying a precision), and the benign effect (i.e., none)
+of the
+.Cm #
+flag on
+.Cm %n
+and
+.Cm %p
+conversions, as well as other
+nonsensical combinations such as
+.Cm %Ld ,
+are not standard; such combinations
+should be avoided.
.Sh ERRORS
In addition to the errors documented for the
.Xr write 2
.Xr scanf 3 ,
.Xr setlocale 3 ,
.Xr wprintf 3
-.Rs
-.%T "The FreeBSD Security Architecture"
-.Re
-(See
-.Pa "/usr/share/doc/{to be determined}" . )
.Sh STANDARDS
Subject to the caveats noted in the
.Sx BUGS
and
.Fn vsnprintf
functions conform to
-.St -isoC-99 .
+.St -isoC-99 ,
+while
+.Fn dprintf
+and
+.Fn vdprintf
+conform to
+.St -p1003.1-2008 .
.Sh HISTORY
The functions
.Fn asprintf
.An Todd C. Miller Aq Todd.Miller@courtesan.com
for
.Ox 2.3 .
-.Sh BUGS
-The conversion formats
-.Cm \&%D , \&%O ,
-and
-.Cm %U
-are not standard and
-are provided only for backward compatibility.
-The effect of padding the
-.Cm %p
-format with zeros (either by the
-.Cm 0
-flag or by specifying a precision), and the benign effect (i.e., none)
-of the
-.Cm #
-flag on
-.Cm %n
+The
+.Fn dprintf
and
-.Cm %p
-conversions, as well as other
-nonsensical combinations such as
-.Cm %Ld ,
-are not standard; such combinations
-should be avoided.
-.Pp
+.Fn vdprintf
+functions were added in
+.Fx 8.0 .
+.Sh BUGS
The
.Nm
family of functions do not correctly handle multibyte characters in the
projects / apple / libc.git / blobdiff