* ext/date/date_core.c: replaced doc for strftime based on Time's one.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@32010 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 169 insertions, 1 deletions

diff --git a/ext/date/date_core.c b/ext/date/date_core.c
index ee4dd8bc21..ea64204fdd 100644
--- a/ext/date/date_core.c
+++ b/ext/date/date_core.c
@@ -6544,7 +6544,175 @@ date_strftime_internal(int argc, VALUE *argv, VALUE self,
  * call-seq:
  *    d.strftime([format="%F"])  ->  string
  *
- * Formats the date with the given template.
+ *  Formats date according to the directives in the given format
+ *  string.
+ *  The directives begins with a percent (%) character.
+ *  Any text not listed as a directive will be passed through to the
+ *  output string.
+ *
+ *  The directive consists of a percent (%) character,
+ *  zero or more flags, optional minimum field width,
+ *  optional modifier and a conversion specifier
+ *  as follows.
+ *
+ *    %<flags><width><modifier><conversion>
+ *
+ *  Flags:
+ *    -  don't pad a numerical output.
+ *    _  use spaces for padding.
+ *    0  use zeros for padding.
+ *    ^  upcase the result string.
+ *    #  change case.
+ *    :  use colons for %z.
+ *
+ *  The minimum field width specifies the minimum width.
+ *
+ *  The modifier is "E" and "O".
+ *  They are ignored.
+ *
+ *  Format directives:
+ *
+ *    Date (Year, Month, Day):
+ *      %Y - Year with century (can be negative, 4 digits at least)
+ *              -0001, 0000, 1995, 2009, 14292, etc.
+ *      %C - year / 100 (round down.  20 in 2009)
+ *      %y - year % 100 (00..99)
+ *
+ *      %m - Month of the year, zero-padded (01..12)
+ *              %_m  blank-padded ( 1..12)
+ *              %-m  no-padded (1..12)
+ *      %B - The full month name (``January'')
+ *              %^B  uppercased (``JANUARY'')
+ *      %b - The abbreviated month name (``Jan'')
+ *              %^b  uppercased (``JAN'')
+ *      %h - Equivalent to %b
+ *
+ *      %d - Day of the month, zero-padded (01..31)
+ *              %-d  no-padded (1..31)
+ *      %e - Day of the month, blank-padded ( 1..31)
+ *
+ *      %j - Day of the year (001..366)
+ *
+ *    Time (Hour, Minute, Second, Subsecond):
+ *      %H - Hour of the day, 24-hour clock, zero-padded (00..23)
+ *      %k - Hour of the day, 24-hour clock, blank-padded ( 0..23)
+ *      %I - Hour of the day, 12-hour clock, zero-padded (01..12)
+ *      %l - Hour of the day, 12-hour clock, blank-padded ( 1..12)
+ *      %P - Meridian indicator, lowercase (``am'' or ``pm'')
+ *      %p - Meridian indicator, uppercase (``AM'' or ``PM'')
+ *
+ *      %M - Minute of the hour (00..59)
+ *
+ *      %S - Second of the minute (00..60)
+ *
+ *      %L - Millisecond of the second (000..999)
+ *      %N - Fractional seconds digits, default is 9 digits (nanosecond)
+ *              %3N  millisecond (3 digits)
+ *              %6N  microsecond (6 digits)
+ *              %9N  nanosecond (9 digits)
+ *              %12N picosecond (12 digits)
+ *
+ *    Time zone:
+ *      %z - Time zone as hour and minute offset from UTC (e.g. +0900)
+ *              %:z - hour and minute offset from UTC with a colon (e.g. +09:00)
+ *              %::z - hour, minute and second offset from UTC (e.g. +09:00:00)
+ *              %:::z - hour, minute and second offset from UTC
+ *                                                (e.g. +09, +09:30, +09:30:30)
+ *      %Z - Time zone abbreviation name
+ *
+ *    Weekday:
+ *      %A - The full weekday name (``Sunday'')
+ *              %^A  uppercased (``SUNDAY'')
+ *      %a - The abbreviated name (``Sun'')
+ *              %^a  uppercased (``SUN'')
+ *      %u - Day of the week (Monday is 1, 1..7)
+ *      %w - Day of the week (Sunday is 0, 0..6)
+ *
+ *    ISO 8601 week-based year and week number:
+ *    The week 1 of YYYY starts with a Monday and includes YYYY-01-04.
+ *    The days in the year before the first week are in the last week of
+ *    the previous year.
+ *      %G - The week-based year
+ *      %g - The last 2 digits of the week-based year (00..99)
+ *      %V - Week number of the week-based year (01..53)
+ *
+ *    Week number:
+ *    The week 1 of YYYY starts with a Sunday or Monday (according to %U
+ *    or %W).  The days in the year before the first week are in week 0.
+ *      %U - Week number of the year.  The week starts with Sunday.  (00..53)
+ *      %W - Week number of the year.  The week starts with Monday.  (00..53)
+ *
+ *    Seconds since the Epoch:
+ *      %s - Number of seconds since 1970-01-01 00:00:00 UTC.
+ *
+ *    Literal string:
+ *      %n - Newline character (\n)
+ *      %t - Tab character (\t)
+ *      %% - Literal ``%'' character
+ *
+ *    Combination:
+ *      %c - date and time (%a %b %e %T %Y)
+ *      %D - Date (%m/%d/%y)
+ *      %F - The ISO 8601 date format (%Y-%m-%d)
+ *      %v - VMS date (%e-%b-%Y)
+ *      %x - Same as %D
+ *      %X - Same as %T
+ *      %r - 12-hour time (%I:%M:%S %p)
+ *      %R - 24-hour time (%H:%M)
+ *      %T - 24-hour time (%H:%M:%S)
+ *      %+ - date(1) (%a %b %e %H:%M:%S %Z %Y)
+ *
+ *  This method is similar to strftime() function defined in ISO C and POSIX.
+ *  Several directives (%a, %A, %b, %B, %c, %p, %r, %x, %X, %E*, %O* and %Z)
+ *  are locale dependent in the function.
+ *  However this method is locale independent.
+ *  So, the result may differ even if a same format string is used in other
+ *  systems such as C.
+ *  It is good practice to avoid %x and %X because there are corresponding
+ *  locale independent representations, %D and %T.
+ *
+ *  Examples:
+ *
+ *    d = DateTime.new(2007,11,19,8,37,48,"-06:00")
+ *				#=> #<DateTime: 2007-11-19 08:37:48 -0600 ...>
+ *    d.strftime("Printed on %m/%d/%Y")   #=> "Printed on 11/19/2007"
+ *    d.strftime("at %I:%M%p")            #=> "at 08:37AM"
+ *
+ *  Various ISO 8601 formats:
+ *    %Y%m%d           => 20071119                  Calendar date (basic)
+ *    %F               => 2007-11-19                Calendar date (extended)
+ *    %Y-%m            => 2007-11                   Calendar date, reduced accuracy, specific month
+ *    %Y               => 2007                      Calendar date, reduced accuracy, specific year
+ *    %C               => 20                        Calendar date, reduced accuracy, specific century
+ *    %Y%j             => 2007323                   Ordinal date (basic)
+ *    %Y-%j            => 2007-323                  Ordinal date (extended)
+ *    %GW%V%u          => 2007W471                  Week date (basic)
+ *    %G-W%V-%u        => 2007-W47-1                Week date (extended)
+ *    %GW%V            => 2007W47                   Week date, reduced accuracy, specific week (basic)
+ *    %G-W%V           => 2007-W47                  Week date, reduced accuracy, specific week (extended)
+ *    %H%M%S           => 083748                    Local time (basic)
+ *    %T               => 08:37:48                  Local time (extended)
+ *    %H%M             => 0837                      Local time, reduced accuracy, specific minute (basic)
+ *    %H:%M            => 08:37                     Local time, reduced accuracy, specific minute (extended)
+ *    %H               => 08                        Local time, reduced accuracy, specific hour
+ *    %H%M%S,%L        => 083748,000                Local time with decimal fraction, comma as decimal sign (basic)
+ *    %T,%L            => 08:37:48,000              Local time with decimal fraction, comma as decimal sign (extended)
+ *    %H%M%S.%L        => 083748.000                Local time with decimal fraction, full stop as decimal sign (basic)
+ *    %T.%L            => 08:37:48.000              Local time with decimal fraction, full stop as decimal sign (extended)
+ *    %H%M%S%z         => 083748-0600               Local time and the difference from UTC (basic)
+ *    %T%:z            => 08:37:48-06:00            Local time and the difference from UTC (extended)
+ *    %Y%m%dT%H%M%S%z  => 20071119T083748-0600      Date and time of day for calendar date (basic)
+ *    %FT%T%:z         => 2007-11-19T08:37:48-06:00 Date and time of day for calendar date (extended)
+ *    %Y%jT%H%M%S%z    => 2007323T083748-0600       Date and time of day for ordinal date (basic)
+ *    %Y-%jT%T%:z      => 2007-323T08:37:48-06:00   Date and time of day for ordinal date (extended)
+ *    %GW%V%uT%H%M%S%z => 2007W471T083748-0600      Date and time of day for week date (basic)
+ *    %G-W%V-%uT%T%:z  => 2007-W47-1T08:37:48-06:00 Date and time of day for week date (extended)
+ *    %Y%m%dT%H%M      => 20071119T0837             Calendar date and local time (basic)
+ *    %FT%R            => 2007-11-19T08:37          Calendar date and local time (extended)
+ *    %Y%jT%H%MZ       => 2007323T0837Z             Ordinal date and UTC of day (basic)
+ *    %Y-%jT%RZ        => 2007-323T08:37Z           Ordinal date and UTC of day (extended)
+ *    %GW%V%uT%H%M%z   => 2007W471T0837-0600        Week date and local time and difference from UTC (basic)
+ *    %G-W%V-%uT%R%:z  => 2007-W47-1T08:37-06:00    Week date and local time and difference from UTC (extended)
  *
  * See also strftime(3) and strptime.
  */