1DateFormat(3) User Contributed Perl Documentation DateFormat(3)
2
6 Log::Log4perl::DateFormat - Log4perl advanced date formatter helper
7 class
8
10 use Log::Log4perl::DateFormat;
11 my $format = Log::Log4perl::DateFormat->new("HH:mm:ss,SSS");
13 # Simple time, resolution in seconds
15 my $time = time();
16 print $format->format($time), "\n";
17 # => "17:02:39,000"
18 # Advanced time, resultion in milliseconds
20 use Time::HiRes;
21 my ($secs, $msecs) = Time::HiRes::gettimeofday();
22 print $format->format($secs, $msecs), "\n";
23 # => "17:02:39,959"
24
26 "Log::Log4perl::DateFormat" is a low-level helper class for the
27 advanced date formatting functions in "Log::Log4perl::Layout::Pattern‐
28 Layout".
29 Unless you're writing your own Layout class like Log::Log4perl::Lay‐
31 out::PatternLayout, there's probably not much use for you to read this.
32 "Log::Log4perl::DateFormat" is a formatter which allows dates to be
34 formatted according to the log4j spec on
35 http://java.sun.com/j2se/1.5.0/docs/api/java/text/SimpleDateFormat.html
37 which allows the following placeholders to be recognized and processed:
39 Symbol Meaning Presentation Example
41 ------ ------- ------------ -------
42 G era designator (Text) AD
43 y year (Number) 1996
44 M month in year (Text & Number) July & 07
45 d day in month (Number) 10
46 h hour in am/pm (1~12) (Number) 12
47 H hour in day (0~23) (Number) 0
48 m minute in hour (Number) 30
49 s second in minute (Number) 55
50 S millisecond (Number) 978
51 E day in week (Text) Tuesday
52 D day in year (Number) 189
53 F day of week in month (Number) 2 (2nd Wed in July)
54 w week in year (Number) 27
55 W week in month (Number) 2
56 a am/pm marker (Text) PM
57 k hour in day (1~24) (Number) 24
58 K hour in am/pm (0~11) (Number) 0
59 z time zone (Text) Pacific Standard Time
60 Z RFC 822 time zone (Text) -0800
61 ' escape for text (Delimiter)
62 '' single quote (Literal) '
63 For example, if you want to format the current Unix time in "MM/dd
65 HH:mm" format, all you have to do is this:
66 use Log::Log4perl::DateFormat;
68 my $format = Log::Log4perl::DateFormat->new("MM/dd HH:mm");
70 my $time = time();
72 print $format->format($time), "\n";
73 While the "new()" method is expensive, because it parses the format
75 strings and sets up all kinds of structures behind the scenes, followup
76 calls to "format()" are fast, because "DateFormat" will just call
77 "localtime()" and "sprintf()" once to return the formatted date/time
78 string.
79 So, typically, you would initialize the formatter once and then reuse
81 it over and over again to display all kinds of time values.
82 Also, for your convenience, the following predefined formats are avail‐
84 able, just as outlined in the log4j spec:
85 Format Equivalent Example
87 ABSOLUTE "HH:mm:ss,SSS" "15:49:37,459"
88 DATE "dd MMM yyyy HH:mm:ss,SSS" "06 Nov 1994 15:49:37,459"
89 ISO8601 "yyyy-MM-dd HH:mm:ss,SSS" "1999-11-27 15:49:37,459"
90 APACHE "[EEE MMM dd HH:mm:ss yyyy]" "[Wed Mar 16 15:49:37 2005]"
91 So, instead of passing
93 Log::Log4perl::DateFormat->new("HH:mm:ss,SSS");
95 you could just as well say
97 Log::Log4perl::DateFormat->new("ABSOLUTE");
99 and get the same result later on.
101 Known Shortcomings
103 The following placeholders are currently not recognized, unless someone
105 (and that could be you :) implements them:
106 F day of week in month
108 w week in year
109 W week in month
110 k hour in day
111 K hour in am/pm
112 z timezone (but we got 'Z' for the numeric time zone value)
113 Also, "Log::Log4perl::DateFormat" just knows about English week and
115 month names, internationalization support has to be added.
116
119 Mike Schilli, <log4perl@perlmeister.com>
120perl v5.8.8 2002-07-10 DateFormat(3)