Printf "[%08f]\n", 0.0/0.0

Ruby Development
1

e$B0J2<$N$h$&$K!"e(Bprintf e$B$Ge(B NaN, Inf e$B$Ge(B 0 padding
e$B$,5/$3$j$^$9!#e(B

% ./ruby -ve ‘printf “[%08f]\n”, 0.0/0.0’
ruby 1.9.0 (2008-03-06 revision 15699) [i686-linux]
[00000NaN]
% ./ruby -e ‘printf “[%08f]\n”, 1.0/0.0’
[00000Inf]
% ./ruby -e ‘printf “[%08f]\n”, -1.0/0.0’
[-0000Inf]

e$B$7$+$7!"e(BC e$B$N5,3J$G$Oe(B NaN e$B$He(B Inf e$B$K4X$7$F$Oe(B 0
padding e$B$O5/$3e(B
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% uname -srv
Linux 2.6.18-5-686 #1 SMP Mon Dec 24 16:41:07 UTC 2007
% cat tst.c
#include <stdlib.h>
#include <stdio.h>

int main(int argc, char **argv)
{
printf("[%08f]\n", 0.0/0.0);
printf("[%08f]\n", 1.0/0.0);
printf("[%08f]\n", -1.0/0.0);
return 0;
}
% gcc tst.c
% ./a.out
[ nan]
[ inf]
[ -inf]

2

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At Thu, 6 Mar 2008 01:57:27 +0900,
Tanaka A. wrote in [ruby-dev:33994]:

e$B0J2<$N$h$&$K!"e(Bprintf e$B$Ge(B NaN, Inf e$B$Ge(B 0 padding e$B$,5/$3$j$^$9!#e(B

% ./ruby -ve ‘printf “[%08f]\n”, 0.0/0.0’
ruby 1.9.0 (2008-03-06 revision 15699) [i686-linux]
[00000NaN]
% ./ruby -e ‘printf “[%08f]\n”, 1.0/0.0’
[00000Inf]
% ./ruby -e ‘printf “[%08f]\n”, -1.0/0.0’
[-0000Inf]

e$B%F%9%H$b4V0c$C$F$$$k$H$$$&$3$H$G$7$g$&$+!#e(B

Index: sprintf.c

— sprintf.c (revision 15701)
+++ sprintf.c (working copy)
@@ -767,4 +767,5 @@ rb_str_format(int argc, const VALUE *arg
const char *expr;

  •    flags &= ~FZERO;
   if  (isnan(fval)) {
 expr = "NaN";

Index: test/ruby/test_sprintf.rb

— test/ruby/test_sprintf.rb (revision 15701)
+++ test/ruby/test_sprintf.rb (working copy)
@@ -88,7 +88,7 @@ class TestSprintf < Test::Unit::TestCase
assert_equal(" +NaN", sprintf("%+8f", nan))

  • assert_equal(“00000NaN”, sprintf("%08f", nan))
  • assert_equal(" NaN", sprintf("%08f", nan))
    assert_equal(“NaN “, sprintf(”%-08f”, nan))
  • assert_equal("+0000NaN", sprintf("%+08f", nan))

  • assert_equal(" +NaN", sprintf("%+08f", nan))

    assert_equal(" NaN", sprintf("% 8f", nan))
    @@ -96,7 +96,7 @@ class TestSprintf < Test::Unit::TestCase
    assert_equal(" +NaN", sprintf("%+ 8f", nan))

  • assert_equal(" 0000NaN", sprintf("% 08f", nan))
  • assert_equal(" NaN", sprintf("% 08f", nan))
    assert_equal(" NaN “, sprintf(”%- 08f", nan))
  • assert_equal("+0000NaN", sprintf("%+ 08f", nan))
  • assert_equal(" +NaN", sprintf("%+ 08f", nan))
    end

@@ -111,7 +111,7 @@ class TestSprintf < Test::Unit::TestCase
assert_equal(" +Inf", sprintf("%+8f", inf))

  • assert_equal(“00000Inf”, sprintf("%08f", inf))
  • assert_equal(" Inf", sprintf("%08f", inf))
    assert_equal(“Inf “, sprintf(”%-08f”, inf))
  • assert_equal("+0000Inf", sprintf("%+08f", inf))

  • assert_equal(" +Inf", sprintf("%+08f", inf))

    assert_equal(" Inf", sprintf("% 8f", inf))
    @@ -119,7 +119,7 @@ class TestSprintf < Test::Unit::TestCase
    assert_equal(" +Inf", sprintf("%+ 8f", inf))

  • assert_equal(" 0000Inf", sprintf("% 08f", inf))
  • assert_equal(" Inf", sprintf("% 08f", inf))
    assert_equal(" Inf “, sprintf(”%- 08f", inf))
  • assert_equal("+0000Inf", sprintf("%+ 08f", inf))

  • assert_equal(" +Inf", sprintf("%+ 08f", inf))

    assert_equal("-Inf", sprintf("%f", -inf))
    @@ -131,7 +131,7 @@ class TestSprintf < Test::Unit::TestCase
    assert_equal(" -Inf", sprintf("%+8f", -inf))

  • assert_equal("-0000Inf", sprintf("%08f", -inf))
  • assert_equal(" -Inf", sprintf("%08f", -inf))
    assert_equal("-Inf “, sprintf(”%-08f", -inf))
  • assert_equal("-0000Inf", sprintf("%+08f", -inf))

  • assert_equal(" -Inf", sprintf("%+08f", -inf))

    assert_equal(" -Inf", sprintf("% 8f", -inf))
    @@ -139,7 +139,7 @@ class TestSprintf < Test::Unit::TestCase
    assert_equal(" -Inf", sprintf("%+ 8f", -inf))

  • assert_equal("-0000Inf", sprintf("% 08f", -inf))
  • assert_equal(" -Inf", sprintf("% 08f", -inf))
    assert_equal("-Inf “, sprintf(”%- 08f", -inf))
  • assert_equal("-0000Inf", sprintf("%+ 08f", -inf))
  • assert_equal(" -Inf", sprintf("%+ 08f", -inf))
    assert_equal(’…f00000000’,
    sprintf("%x", -2**32), ‘[ruby-dev:32351]’)
3

In article [email protected],
Nobuyoshi N. [email protected] writes:

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e$B$?$V$s!#e(B

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   0     For  d,  i,  o,  u,  x,  X, a, A, e, E, f, F, g, and G
         conversions, leading zeros (following  any  indication
         of  sign  or  base) are used to pad to the field width |
         rather than  performing  space  padding,  except  when |
         converting  an  infinity or NaN.  If the 0 and - flags
         both appear, the 0 flag is ignored.  For d, i,  o,  u,
         x, and X conversions, if a precision is specified, the
         0  flag  is  ignored.   For  other  conversions,   the
         behavior is undefined.

e$B$H$+e(B

   220When  applied  to  infinite and NaN values, the -, +, and
      space flag characters have their usual meaning; the # and
      0 flag characters have no effect.

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