Commit | Line | Data |
---|---|---|
f6227721 SL |
1 | #ifndef lint |
2 | static char sccsid[] = "@(#)cal.c 4.3 (Berkeley) 83/08/11"; | |
3 | #endif | |
4 | ||
b2c306be BJ |
5 | char dayw[] = { |
6 | " S M Tu W Th F S" | |
7 | }; | |
8 | char *smon[]= { | |
9 | "January", "February", "March", "April", | |
10 | "May", "June", "July", "August", | |
11 | "September", "October", "November", "December", | |
12 | }; | |
13 | char string[432]; | |
14 | main(argc, argv) | |
15 | char *argv[]; | |
16 | { | |
17 | register y, i, j; | |
18 | int m; | |
19 | ||
20 | if(argc < 2) { | |
21 | printf("usage: cal [month] year\n"); | |
22 | exit(0); | |
23 | } | |
24 | if(argc == 2) | |
25 | goto xlong; | |
26 | ||
27 | /* | |
28 | * print out just month | |
29 | */ | |
30 | ||
31 | m = number(argv[1]); | |
32 | if(m<1 || m>12) | |
33 | goto badarg; | |
34 | y = number(argv[2]); | |
35 | if(y<1 || y>9999) | |
36 | goto badarg; | |
37 | printf(" %s %u\n", smon[m-1], y); | |
38 | printf("%s\n", dayw); | |
39 | cal(m, y, string, 24); | |
40 | for(i=0; i<6*24; i+=24) | |
41 | pstr(string+i, 24); | |
42 | exit(0); | |
43 | ||
44 | /* | |
45 | * print out complete year | |
46 | */ | |
47 | ||
48 | xlong: | |
49 | y = number(argv[1]); | |
50 | if(y<1 || y>9999) | |
51 | goto badarg; | |
52 | printf("\n\n\n"); | |
53 | printf(" %u\n", y); | |
54 | printf("\n"); | |
55 | for(i=0; i<12; i+=3) { | |
56 | for(j=0; j<6*72; j++) | |
57 | string[j] = '\0'; | |
58 | printf(" %.3s", smon[i]); | |
59 | printf(" %.3s", smon[i+1]); | |
60 | printf(" %.3s\n", smon[i+2]); | |
61 | printf("%s %s %s\n", dayw, dayw, dayw); | |
62 | cal(i+1, y, string, 72); | |
63 | cal(i+2, y, string+23, 72); | |
64 | cal(i+3, y, string+46, 72); | |
65 | for(j=0; j<6*72; j+=72) | |
66 | pstr(string+j, 72); | |
67 | } | |
68 | printf("\n\n\n"); | |
69 | exit(0); | |
70 | ||
71 | badarg: | |
72 | printf("Bad argument\n"); | |
73 | } | |
74 | ||
75 | number(str) | |
76 | char *str; | |
77 | { | |
78 | register n, c; | |
79 | register char *s; | |
80 | ||
81 | n = 0; | |
82 | s = str; | |
83 | while(c = *s++) { | |
84 | if(c<'0' || c>'9') | |
85 | return(0); | |
86 | n = n*10 + c-'0'; | |
87 | } | |
88 | return(n); | |
89 | } | |
90 | ||
91 | pstr(str, n) | |
92 | char *str; | |
93 | { | |
94 | register i; | |
95 | register char *s; | |
96 | ||
97 | s = str; | |
98 | i = n; | |
99 | while(i--) | |
100 | if(*s++ == '\0') | |
101 | s[-1] = ' '; | |
102 | i = n+1; | |
103 | while(i--) | |
104 | if(*--s != ' ') | |
105 | break; | |
106 | s[1] = '\0'; | |
107 | printf("%s\n", str); | |
108 | } | |
109 | ||
110 | char mon[] = { | |
111 | 0, | |
112 | 31, 29, 31, 30, | |
113 | 31, 30, 31, 31, | |
114 | 30, 31, 30, 31, | |
115 | }; | |
116 | ||
117 | cal(m, y, p, w) | |
118 | char *p; | |
119 | { | |
120 | register d, i; | |
121 | register char *s; | |
122 | ||
123 | s = p; | |
124 | d = jan1(y); | |
125 | mon[2] = 29; | |
126 | mon[9] = 30; | |
127 | ||
128 | switch((jan1(y+1)+7-d)%7) { | |
129 | ||
130 | /* | |
131 | * non-leap year | |
132 | */ | |
133 | case 1: | |
134 | mon[2] = 28; | |
135 | break; | |
136 | ||
137 | /* | |
138 | * 1752 | |
139 | */ | |
140 | default: | |
141 | mon[9] = 19; | |
142 | break; | |
143 | ||
144 | /* | |
145 | * leap year | |
146 | */ | |
147 | case 2: | |
148 | ; | |
149 | } | |
150 | for(i=1; i<m; i++) | |
151 | d += mon[i]; | |
152 | d %= 7; | |
153 | s += 3*d; | |
154 | for(i=1; i<=mon[m]; i++) { | |
155 | if(i==3 && mon[m]==19) { | |
156 | i += 11; | |
157 | mon[m] += 11; | |
158 | } | |
159 | if(i > 9) | |
160 | *s = i/10+'0'; | |
161 | s++; | |
162 | *s++ = i%10+'0'; | |
163 | s++; | |
164 | if(++d == 7) { | |
165 | d = 0; | |
166 | s = p+w; | |
167 | p = s; | |
168 | } | |
169 | } | |
170 | } | |
171 | ||
172 | /* | |
173 | * return day of the week | |
174 | * of jan 1 of given year | |
175 | */ | |
176 | ||
177 | jan1(yr) | |
178 | { | |
179 | register y, d; | |
180 | ||
181 | /* | |
182 | * normal gregorian calendar | |
183 | * one extra day per four years | |
184 | */ | |
185 | ||
186 | y = yr; | |
187 | d = 4+y+(y+3)/4; | |
188 | ||
189 | /* | |
190 | * julian calendar | |
191 | * regular gregorian | |
192 | * less three days per 400 | |
193 | */ | |
194 | ||
195 | if(y > 1800) { | |
196 | d -= (y-1701)/100; | |
197 | d += (y-1601)/400; | |
198 | } | |
199 | ||
200 | /* | |
201 | * great calendar changeover instant | |
202 | */ | |
203 | ||
204 | if(y > 1752) | |
205 | d += 3; | |
206 | ||
207 | return(d%7); | |
208 | } |