aboutsummaryrefslogtreecommitdiffstats
path: root/psxtime.scm
blob: 3589c36fbe7df33cf3032b2bf82811797f5f663f (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
;;;; "psxtime.scm" Posix time conversion routines
;;; Copyright (C) 1994, 1997 Aubrey Jaffer
;
;Permission to copy this software, to modify it, to redistribute it,
;to distribute modified versions, and to use it for any purpose is
;granted, subject to the following restrictions and understandings.
;
;1.  Any copy made of this software must include this copyright notice
;in full.
;
;2.  I have made no warranty or representation that the operation of
;this software will be error-free, and I am under no obligation to
;provide any services, by way of maintenance, update, or otherwise.
;
;3.  In conjunction with products arising from the use of this
;material, there shall be no use of my name in any advertising,
;promotional, or sales literature without prior written consent in
;each case.

;;; No, it doesn't do leap seconds.

(require 'multiarg-apply)
(require 'time-core)
(require-if 'compiling 'time-zone)
;@
(define (tz:std-offset zone)
  (case (vector-ref zone 0)
    ((tz:fixed) (vector-ref zone 3))
    ((tz:rule) (vector-ref zone 4))
    ((tz:file)
     (let ((mode-table (vector-ref zone 2)))
       (do ((type-idx 0 (+ 1 type-idx)))
	   ((or (>= type-idx (vector-length mode-table))
		(not (vector-ref (vector-ref mode-table type-idx) 2)))
	    (if (>= type-idx (vector-length mode-table))
		(vector-ref (vector-ref mode-table 0) 1)
		(- (vector-ref (vector-ref mode-table type-idx) 1)))))))
    (else (slib:error 'tz:std-offset "unknown timezone type" zone))))
;@
(define (localtime caltime . tz)
  (require 'time-zone)
  (set! tz (if (null? tz) (tzset) (car tz)))
  (apply time:split caltime (tz:params caltime tz)))
;@
(define (mktime univtime . tz)
  (require 'time-zone)
  (set! tz (if (null? tz) (tzset) (car tz)))
  (offset-time (gmktime univtime) (tz:std-offset tz)))
;@
(define (gmktime univtime)
  (time:invert time:gmtime univtime))
;@
(define (asctime decoded)
  (let ((days   '#("Sun" "Mon" "Tue" "Wed" "Thu" "Fri" "Sat"))
	(months '#("Jan" "Feb" "Mar" "Apr" "May" "Jun"
			 "Jul" "Aug" "Sep" "Oct" "Nov" "Dec"))
	(number->2digits
	 (lambda (n ch)
	   (set! n (number->string n))
	   (if (= 1 (string-length n))
	       (string-append ch n)
	       n))))
    (string-append
     (vector-ref days (vector-ref decoded 6)) " "
     (vector-ref months (vector-ref decoded 4)) " "
     (number->2digits (vector-ref decoded 3) " ") " "
     (number->2digits (vector-ref decoded 2) "0") ":"
     (number->2digits (vector-ref decoded 1) "0") ":"
     (number->2digits (vector-ref decoded 0) "0") " "
     (number->string (+ 1900 (vector-ref decoded 5)))
     (string #\newline))))
;@
(define (ctime . args)
  (time:asctime (apply time:localtime args)))
;@
(define (gtime time)
  (time:asctime (time:gmtime time)))

;;;	GMT				Local -- take optional 2nd TZ arg
;;@
(define gmtime time:gmtime)

(define time:localtime localtime)
;;(define time:gmktime gmktime)	(define time:mktime mktime)
;;(define time:gtime gtime)	(define time:ctime ctime)

(define time:asctime asctime)

;@
(define daylight? #f)
(define *timezone* 0)
(define tzname '#("UTC" "???"))

(define tz:default #f)

;;;@ Interpret the TZ envariable.
(define (tzset . opt-tz)
  (define tz (if (null? opt-tz)
		 (getenv "TZ")
		 (car opt-tz)))
  (if (or (not tz:default)
	  (and (string? tz) (not (string-ci=? tz (vector-ref tz:default 1)))))
      (let ()
	(require 'time-zone)
	(set! tz:default (or (time-zone tz) '#(tz:fixed "UTC" "GMT" 0)))))
  (case (vector-ref tz:default 0)
    ((tz:fixed)
     (set! tzname (vector (vector-ref tz:default 2) "???"))
     (set! daylight? #f)
     (set! *timezone* (vector-ref tz:default 3)))
    ((tz:rule)
     (set! tzname (vector (vector-ref tz:default 2)
			  (vector-ref tz:default 3)))
     (set! daylight? #t)
     (set! *timezone* (vector-ref tz:default 4)))
    ((tz:file)
     (let ((mode-table (vector-ref tz:default 2))
	   (transition-types (vector-ref tz:default 5)))
       (set! daylight? #f)
       (set! *timezone* (vector-ref (vector-ref mode-table 0) 1))
       (set! tzname (make-vector 2 #f))
       (do ((type-idx 0 (+ 1 type-idx)))
	   ((>= type-idx (vector-length mode-table)))
	 (let ((rec (vector-ref mode-table type-idx)))
	   (if (vector-ref rec 2)
	       (set! daylight? #t)
	       (set! *timezone* (- (vector-ref rec 1))))))

       (do ((transition-idx (+ -1 (vector-length transition-types))
			    (+ -1 transition-idx)))
	   ((or (negative? transition-idx)
		(and (vector-ref tzname 0) (vector-ref tzname 1))))
	 (let ((rec (vector-ref mode-table
				(vector-ref transition-types transition-idx))))
	   (if (vector-ref rec 2)
	       (if (not (vector-ref tzname 1))
		   (vector-set! tzname 1 (vector-ref rec 0)))
	       (if (not (vector-ref tzname 0))
		   (vector-set! tzname 0 (vector-ref rec 0))))))))
    (else (slib:error 'tzset "unknown timezone type" tz)))
  tz:default)