Commit | Line | Data |
---|---|---|
86530b38 AT |
1 | .\" Automatically generated by Pod::Man v1.34, Pod::Parser v1.13 |
2 | .\" | |
3 | .\" Standard preamble: | |
4 | .\" ======================================================================== | |
5 | .de Sh \" Subsection heading | |
6 | .br | |
7 | .if t .Sp | |
8 | .ne 5 | |
9 | .PP | |
10 | \fB\\$1\fR | |
11 | .PP | |
12 | .. | |
13 | .de Sp \" Vertical space (when we can't use .PP) | |
14 | .if t .sp .5v | |
15 | .if n .sp | |
16 | .. | |
17 | .de Vb \" Begin verbatim text | |
18 | .ft CW | |
19 | .nf | |
20 | .ne \\$1 | |
21 | .. | |
22 | .de Ve \" End verbatim text | |
23 | .ft R | |
24 | .fi | |
25 | .. | |
26 | .\" Set up some character translations and predefined strings. \*(-- will | |
27 | .\" give an unbreakable dash, \*(PI will give pi, \*(L" will give a left | |
28 | .\" double quote, and \*(R" will give a right double quote. | will give a | |
29 | .\" real vertical bar. \*(C+ will give a nicer C++. Capital omega is used to | |
30 | .\" do unbreakable dashes and therefore won't be available. \*(C` and \*(C' | |
31 | .\" expand to `' in nroff, nothing in troff, for use with C<>. | |
32 | .tr \(*W-|\(bv\*(Tr | |
33 | .ds C+ C\v'-.1v'\h'-1p'\s-2+\h'-1p'+\s0\v'.1v'\h'-1p' | |
34 | .ie n \{\ | |
35 | . ds -- \(*W- | |
36 | . ds PI pi | |
37 | . if (\n(.H=4u)&(1m=24u) .ds -- \(*W\h'-12u'\(*W\h'-12u'-\" diablo 10 pitch | |
38 | . if (\n(.H=4u)&(1m=20u) .ds -- \(*W\h'-12u'\(*W\h'-8u'-\" diablo 12 pitch | |
39 | . ds L" "" | |
40 | . ds R" "" | |
41 | . ds C` "" | |
42 | . ds C' "" | |
43 | 'br\} | |
44 | .el\{\ | |
45 | . ds -- \|\(em\| | |
46 | . ds PI \(*p | |
47 | . ds L" `` | |
48 | . ds R" '' | |
49 | 'br\} | |
50 | .\" | |
51 | .\" If the F register is turned on, we'll generate index entries on stderr for | |
52 | .\" titles (.TH), headers (.SH), subsections (.Sh), items (.Ip), and index | |
53 | .\" entries marked with X<> in POD. Of course, you'll have to process the | |
54 | .\" output yourself in some meaningful fashion. | |
55 | .if \nF \{\ | |
56 | . de IX | |
57 | . tm Index:\\$1\t\\n%\t"\\$2" | |
58 | .. | |
59 | . nr % 0 | |
60 | . rr F | |
61 | .\} | |
62 | .\" | |
63 | .\" For nroff, turn off justification. Always turn off hyphenation; it makes | |
64 | .\" way too many mistakes in technical documents. | |
65 | .hy 0 | |
66 | .if n .na | |
67 | .\" | |
68 | .\" Accent mark definitions (@(#)ms.acc 1.5 88/02/08 SMI; from UCB 4.2). | |
69 | .\" Fear. Run. Save yourself. No user-serviceable parts. | |
70 | . \" fudge factors for nroff and troff | |
71 | .if n \{\ | |
72 | . ds #H 0 | |
73 | . ds #V .8m | |
74 | . ds #F .3m | |
75 | . ds #[ \f1 | |
76 | . ds #] \fP | |
77 | .\} | |
78 | .if t \{\ | |
79 | . ds #H ((1u-(\\\\n(.fu%2u))*.13m) | |
80 | . ds #V .6m | |
81 | . ds #F 0 | |
82 | . ds #[ \& | |
83 | . ds #] \& | |
84 | .\} | |
85 | . \" simple accents for nroff and troff | |
86 | .if n \{\ | |
87 | . ds ' \& | |
88 | . ds ` \& | |
89 | . ds ^ \& | |
90 | . ds , \& | |
91 | . ds ~ ~ | |
92 | . ds / | |
93 | .\} | |
94 | .if t \{\ | |
95 | . ds ' \\k:\h'-(\\n(.wu*8/10-\*(#H)'\'\h"|\\n:u" | |
96 | . ds ` \\k:\h'-(\\n(.wu*8/10-\*(#H)'\`\h'|\\n:u' | |
97 | . ds ^ \\k:\h'-(\\n(.wu*10/11-\*(#H)'^\h'|\\n:u' | |
98 | . ds , \\k:\h'-(\\n(.wu*8/10)',\h'|\\n:u' | |
99 | . ds ~ \\k:\h'-(\\n(.wu-\*(#H-.1m)'~\h'|\\n:u' | |
100 | . ds / \\k:\h'-(\\n(.wu*8/10-\*(#H)'\z\(sl\h'|\\n:u' | |
101 | .\} | |
102 | . \" troff and (daisy-wheel) nroff accents | |
103 | .ds : \\k:\h'-(\\n(.wu*8/10-\*(#H+.1m+\*(#F)'\v'-\*(#V'\z.\h'.2m+\*(#F'.\h'|\\n:u'\v'\*(#V' | |
104 | .ds 8 \h'\*(#H'\(*b\h'-\*(#H' | |
105 | .ds o \\k:\h'-(\\n(.wu+\w'\(de'u-\*(#H)/2u'\v'-.3n'\*(#[\z\(de\v'.3n'\h'|\\n:u'\*(#] | |
106 | .ds d- \h'\*(#H'\(pd\h'-\w'~'u'\v'-.25m'\f2\(hy\fP\v'.25m'\h'-\*(#H' | |
107 | .ds D- D\\k:\h'-\w'D'u'\v'-.11m'\z\(hy\v'.11m'\h'|\\n:u' | |
108 | .ds th \*(#[\v'.3m'\s+1I\s-1\v'-.3m'\h'-(\w'I'u*2/3)'\s-1o\s+1\*(#] | |
109 | .ds Th \*(#[\s+2I\s-2\h'-\w'I'u*3/5'\v'-.3m'o\v'.3m'\*(#] | |
110 | .ds ae a\h'-(\w'a'u*4/10)'e | |
111 | .ds Ae A\h'-(\w'A'u*4/10)'E | |
112 | . \" corrections for vroff | |
113 | .if v .ds ~ \\k:\h'-(\\n(.wu*9/10-\*(#H)'\s-2\u~\d\s+2\h'|\\n:u' | |
114 | .if v .ds ^ \\k:\h'-(\\n(.wu*10/11-\*(#H)'\v'-.4m'^\v'.4m'\h'|\\n:u' | |
115 | . \" for low resolution devices (crt and lpr) | |
116 | .if \n(.H>23 .if \n(.V>19 \ | |
117 | \{\ | |
118 | . ds : e | |
119 | . ds 8 ss | |
120 | . ds o a | |
121 | . ds d- d\h'-1'\(ga | |
122 | . ds D- D\h'-1'\(hy | |
123 | . ds th \o'bp' | |
124 | . ds Th \o'LP' | |
125 | . ds ae ae | |
126 | . ds Ae AE | |
127 | .\} | |
128 | .rm #[ #] #H #V #F C | |
129 | .\" ======================================================================== | |
130 | .\" | |
131 | .IX Title "Time::Local 3" | |
132 | .TH Time::Local 3 "2002-06-01" "perl v5.8.0" "Perl Programmers Reference Guide" | |
133 | .SH "NAME" | |
134 | Time::Local \- efficiently compute time from local and GMT time | |
135 | .SH "SYNOPSIS" | |
136 | .IX Header "SYNOPSIS" | |
137 | .Vb 2 | |
138 | \& $time = timelocal($sec,$min,$hour,$mday,$mon,$year); | |
139 | \& $time = timegm($sec,$min,$hour,$mday,$mon,$year); | |
140 | .Ve | |
141 | .SH "DESCRIPTION" | |
142 | .IX Header "DESCRIPTION" | |
143 | These routines are the inverse of built-in perl functions \fIlocaltime()\fR | |
144 | and \fIgmtime()\fR. They accept a date as a six-element array, and return | |
145 | the corresponding \fItime\fR\|(2) value in seconds since the Epoch (Midnight, | |
146 | January 1, 1970). This value can be positive or negative. | |
147 | .PP | |
148 | It is worth drawing particular attention to the expected ranges for | |
149 | the values provided. The value for the day of the month is the actual day | |
150 | (ie 1..31), while the month is the number of months since January (0..11). | |
151 | This is consistent with the values returned from \fIlocaltime()\fR and \fIgmtime()\fR. | |
152 | .PP | |
153 | The \fItimelocal()\fR and \fItimegm()\fR functions perform range checking on the | |
154 | input \f(CW$sec\fR, \f(CW$min\fR, \f(CW$hour\fR, \f(CW$mday\fR, and \f(CW$mon\fR values by default. If you'd | |
155 | rather they didn't, you can explicitly import the \fItimelocal_nocheck()\fR | |
156 | and \fItimegm_nocheck()\fR functions. | |
157 | .PP | |
158 | .Vb 1 | |
159 | \& use Time::Local 'timelocal_nocheck'; | |
160 | .Ve | |
161 | .PP | |
162 | .Vb 3 | |
163 | \& { | |
164 | \& # The 365th day of 1999 | |
165 | \& print scalar localtime timelocal_nocheck 0,0,0,365,0,99; | |
166 | .Ve | |
167 | .PP | |
168 | .Vb 2 | |
169 | \& # The twenty thousandth day since 1970 | |
170 | \& print scalar localtime timelocal_nocheck 0,0,0,20000,0,70; | |
171 | .Ve | |
172 | .PP | |
173 | .Vb 3 | |
174 | \& # And even the 10,000,000th second since 1999! | |
175 | \& print scalar localtime timelocal_nocheck 10000000,0,0,1,0,99; | |
176 | \& } | |
177 | .Ve | |
178 | .PP | |
179 | Your mileage may vary when trying these with minutes and hours, | |
180 | and it doesn't work at all for months. | |
181 | .PP | |
182 | Strictly speaking, the year should also be specified in a form consistent | |
183 | with \fIlocaltime()\fR, i.e. the offset from 1900. | |
184 | In order to make the interpretation of the year easier for humans, | |
185 | however, who are more accustomed to seeing years as two-digit or four-digit | |
186 | values, the following conventions are followed: | |
187 | .IP "\(bu" 4 | |
188 | Years greater than 999 are interpreted as being the actual year, | |
189 | rather than the offset from 1900. Thus, 1963 would indicate the year | |
190 | Martin Luther King won the Nobel prize, not the year 2863. | |
191 | .IP "\(bu" 4 | |
192 | Years in the range 100..999 are interpreted as offset from 1900, | |
193 | so that 112 indicates 2012. This rule also applies to years less than zero | |
194 | (but see note below regarding date range). | |
195 | .IP "\(bu" 4 | |
196 | Years in the range 0..99 are interpreted as shorthand for years in the | |
197 | rolling \*(L"current century,\*(R" defined as 50 years on either side of the current | |
198 | year. Thus, today, in 1999, 0 would refer to 2000, and 45 to 2045, | |
199 | but 55 would refer to 1955. Twenty years from now, 55 would instead refer | |
200 | to 2055. This is messy, but matches the way people currently think about | |
201 | two digit dates. Whenever possible, use an absolute four digit year instead. | |
202 | .PP | |
203 | The scheme above allows interpretation of a wide range of dates, particularly | |
204 | if 4\-digit years are used. | |
205 | .PP | |
206 | Please note, however, that the range of dates that can be actually be handled | |
207 | depends on the size of an integer (time_t) on a given platform. | |
208 | Currently, this is 32 bits for most systems, yielding an approximate range | |
209 | from Dec 1901 to Jan 2038. | |
210 | .PP | |
211 | Both \fItimelocal()\fR and \fItimegm()\fR croak if given dates outside the supported | |
212 | range. | |
213 | .SH "IMPLEMENTATION" | |
214 | .IX Header "IMPLEMENTATION" | |
215 | These routines are quite efficient and yet are always guaranteed to agree | |
216 | with \fIlocaltime()\fR and \fIgmtime()\fR. We manage this by caching the start times | |
217 | of any months we've seen before. If we know the start time of the month, | |
218 | we can always calculate any time within the month. The start times | |
219 | are calculated using a mathematical formula. Unlike other algorithms | |
220 | that do multiple calls to \fIgmtime()\fR. | |
221 | .PP | |
222 | \&\fItimelocal()\fR is implemented using the same cache. We just assume that we're | |
223 | translating a \s-1GMT\s0 time, and then fudge it when we're done for the timezone | |
224 | and daylight savings arguments. Note that the timezone is evaluated for | |
225 | each date because countries occasionally change their official timezones. | |
226 | Assuming that \fIlocaltime()\fR corrects for these changes, this routine will | |
227 | also be correct. | |
228 | .SH "BUGS" | |
229 | .IX Header "BUGS" | |
230 | The whole scheme for interpreting two-digit years can be considered a bug. | |
231 | .PP | |
232 | The proclivity to \fIcroak()\fR is probably a bug. |