diff options
Diffstat (limited to 'manual/stdio.texi')
| -rw-r--r-- | manual/stdio.texi | 30 |
1 files changed, 21 insertions, 9 deletions
diff --git a/manual/stdio.texi b/manual/stdio.texi index 1d235be68d..29d01b9ec9 100644 --- a/manual/stdio.texi +++ b/manual/stdio.texi @@ -1664,9 +1664,9 @@ an @code{int} argument should be printed in decimal notation, the the @samp{%%} conversion to print a literal @samp{%} character. There are also conversions for printing an integer argument as an -unsigned value in octal, decimal, or hexadecimal radix (@samp{%o}, -@samp{%u}, or @samp{%x}, respectively); or as a character value -(@samp{%c}). +unsigned value in binary, octal, decimal, or hexadecimal radix +(@samp{%b}, @samp{%o}, @samp{%u}, or @samp{%x}, respectively); or as a +character value (@samp{%c}). Floating-point numbers can be printed in normal, fixed-point notation using the @samp{%f} conversion or in exponential notation using the @@ -1825,6 +1825,13 @@ Conversions}, for details. @samp{%d} and @samp{%i} are synonymous for output, but are different when used with @code{scanf} for input (@pxref{Table of Input Conversions}). +@item @samp{%b}, @samp{%B} +Print an integer as an unsigned binary number. @samp{%b} uses +lower-case @samp{b} with the @samp{#} flag and @samp{%B} uses +upper-case. @samp{%b} is an ISO C2X feature; @samp{%B} is an +extension recommended by ISO C2X. @xref{Integer Conversions}, for +details. + @item @samp{%o} Print an integer as an unsigned octal number. @xref{Integer Conversions}, for details. @@ -1901,15 +1908,17 @@ simply ignored; this is sometimes useful. @subsection Integer Conversions This section describes the options for the @samp{%d}, @samp{%i}, -@samp{%o}, @samp{%u}, @samp{%x}, and @samp{%X} conversion +@samp{%b}, @samp{%B}, @samp{%o}, @samp{%u}, @samp{%x}, and @samp{%X} conversion specifications. These conversions print integers in various formats. The @samp{%d} and @samp{%i} conversion specifications both print an -@code{int} argument as a signed decimal number; while @samp{%o}, -@samp{%u}, and @samp{%x} print the argument as an unsigned octal, +@code{int} argument as a signed decimal number; while @samp{b}, @samp{%o}, +@samp{%u}, and @samp{%x} print the argument as an unsigned binary, octal, decimal, or hexadecimal number (respectively). The @samp{%X} conversion specification is just like @samp{%x} except that it uses the characters -@samp{ABCDEF} as digits instead of @samp{abcdef}. +@samp{ABCDEF} as digits instead of @samp{abcdef}. The @samp{%B} +conversion specification is just like @samp{%b} except that, with the +@samp{#} flag, the output starts with @samp{0B} instead of @samp{0b}. The following flags are meaningful: @@ -1931,7 +1940,9 @@ includes a sign, this flag is ignored if you supply both of them. @item @samp{#} For the @samp{%o} conversion, this forces the leading digit to be @samp{0}, as if by increasing the precision. For @samp{%x} or -@samp{%X}, this prefixes a leading @samp{0x} or @samp{0X} (respectively) +@samp{%X}, this prefixes a leading @samp{0x} or @samp{0X} +(respectively) to the result. For @samp{%b} or @samp{%B}, this +prefixes a leading @samp{0b} or @samp{0B} (respectively) to the result. This doesn't do anything useful for the @samp{%d}, @samp{%i}, or @samp{%u} conversions. Using this flag produces output which can be parsed by the @code{strtoul} function (@pxref{Parsing of @@ -1957,7 +1968,8 @@ characters at all are produced. Without a type modifier, the corresponding argument is treated as an @code{int} (for the signed conversions @samp{%i} and @samp{%d}) or -@code{unsigned int} (for the unsigned conversions @samp{%o}, @samp{%u}, +@code{unsigned int} (for the unsigned conversions @samp{%b}, +@samp{%B}, @samp{%o}, @samp{%u}, @samp{%x}, and @samp{%X}). Recall that since @code{printf} and friends are variadic, any @code{char} and @code{short} arguments are automatically converted to @code{int} by the default argument |