Commit | Line | Data |
---|---|---|
9c79dca0 BJ |
1 | char dayw[] = { |
2 | " S M Tu W Th F S" | |
3 | }; | |
4 | char *smon[]= { | |
5 | "January", "February", "March", "April", | |
6 | "May", "June", "July", "August", | |
7 | "September", "October", "November", "December", | |
8 | }; | |
9 | char string[432]; | |
10 | main(argc, argv) | |
11 | char *argv[]; | |
12 | { | |
13 | register y, i, j; | |
14 | int m; | |
15 | ||
16 | if(argc < 2) { | |
17 | printf("usage: cal [month] year\n"); | |
18 | exit(0); | |
19 | } | |
20 | if(argc == 2) | |
21 | goto xlong; | |
22 | ||
23 | /* | |
24 | * print out just month | |
25 | */ | |
26 | ||
27 | m = number(argv[1]); | |
28 | if(m<1 || m>12) | |
29 | goto badarg; | |
30 | y = number(argv[2]); | |
31 | if(y<1 || y>9999) | |
32 | goto badarg; | |
33 | printf(" %s %u\n", smon[m-1], y); | |
34 | printf("%s\n", dayw); | |
35 | cal(m, y, string, 24); | |
36 | for(i=0; i<6*24; i+=24) | |
37 | pstr(string+i, 24); | |
38 | exit(0); | |
39 | ||
40 | /* | |
41 | * print out complete year | |
42 | */ | |
43 | ||
44 | xlong: | |
45 | y = number(argv[1]); | |
46 | if(y<1 || y>9999) | |
47 | goto badarg; | |
48 | printf("\n\n\n"); | |
49 | printf(" %u\n", y); | |
50 | printf("\n"); | |
51 | for(i=0; i<12; i+=3) { | |
52 | for(j=0; j<6*72; j++) | |
53 | string[j] = '\0'; | |
54 | printf(" %.3s", smon[i]); | |
55 | printf(" %.3s", smon[i+1]); | |
56 | printf(" %.3s\n", smon[i+2]); | |
57 | printf("%s %s %s\n", dayw, dayw, dayw); | |
58 | cal(i+1, y, string, 72); | |
59 | cal(i+2, y, string+23, 72); | |
60 | cal(i+3, y, string+46, 72); | |
61 | for(j=0; j<6*72; j+=72) | |
62 | pstr(string+j, 72); | |
63 | } | |
64 | printf("\n\n\n"); | |
65 | exit(0); | |
66 | ||
67 | badarg: | |
68 | printf("Bad argument\n"); | |
69 | } | |
70 | ||
71 | number(str) | |
72 | char *str; | |
73 | { | |
74 | register n, c; | |
75 | register char *s; | |
76 | ||
77 | n = 0; | |
78 | s = str; | |
79 | while(c = *s++) { | |
80 | if(c<'0' || c>'9') | |
81 | return(0); | |
82 | n = n*10 + c-'0'; | |
83 | } | |
84 | return(n); | |
85 | } | |
86 | ||
87 | pstr(str, n) | |
88 | char *str; | |
89 | { | |
90 | register i; | |
91 | register char *s; | |
92 | ||
93 | s = str; | |
94 | i = n; | |
95 | while(i--) | |
96 | if(*s++ == '\0') | |
97 | s[-1] = ' '; | |
98 | i = n+1; | |
99 | while(i--) | |
100 | if(*--s != ' ') | |
101 | break; | |
102 | s[1] = '\0'; | |
103 | printf("%s\n", str); | |
104 | } | |
105 | ||
106 | char mon[] = { | |
107 | 0, | |
108 | 31, 29, 31, 30, | |
109 | 31, 30, 31, 31, | |
110 | 30, 31, 30, 31, | |
111 | }; | |
112 | ||
113 | cal(m, y, p, w) | |
114 | char *p; | |
115 | { | |
116 | register d, i; | |
117 | register char *s; | |
118 | ||
119 | s = p; | |
120 | d = jan1(y); | |
121 | mon[2] = 29; | |
122 | mon[9] = 30; | |
123 | ||
124 | switch((jan1(y+1)+7-d)%7) { | |
125 | ||
126 | /* | |
127 | * non-leap year | |
128 | */ | |
129 | case 1: | |
130 | mon[2] = 28; | |
131 | break; | |
132 | ||
133 | /* | |
134 | * 1752 | |
135 | */ | |
136 | default: | |
137 | mon[9] = 19; | |
138 | break; | |
139 | ||
140 | /* | |
141 | * leap year | |
142 | */ | |
143 | case 2: | |
144 | ; | |
145 | } | |
146 | for(i=1; i<m; i++) | |
147 | d += mon[i]; | |
148 | d %= 7; | |
149 | s += 3*d; | |
150 | for(i=1; i<=mon[m]; i++) { | |
151 | if(i==3 && mon[m]==19) { | |
152 | i += 11; | |
153 | mon[m] += 11; | |
154 | } | |
155 | if(i > 9) | |
156 | *s = i/10+'0'; | |
157 | s++; | |
158 | *s++ = i%10+'0'; | |
159 | s++; | |
160 | if(++d == 7) { | |
161 | d = 0; | |
162 | s = p+w; | |
163 | p = s; | |
164 | } | |
165 | } | |
166 | } | |
167 | ||
168 | /* | |
169 | * return day of the week | |
170 | * of jan 1 of given year | |
171 | */ | |
172 | ||
173 | jan1(yr) | |
174 | { | |
175 | register y, d; | |
176 | ||
177 | /* | |
178 | * normal gregorian calendar | |
179 | * one extra day per four years | |
180 | */ | |
181 | ||
182 | y = yr; | |
183 | d = 4+y+(y+3)/4; | |
184 | ||
185 | /* | |
186 | * julian calendar | |
187 | * regular gregorian | |
188 | * less three days per 400 | |
189 | */ | |
190 | ||
191 | if(y > 1800) { | |
192 | d -= (y-1701)/100; | |
193 | d += (y-1601)/400; | |
194 | } | |
195 | ||
196 | /* | |
197 | * great calendar changeover instant | |
198 | */ | |
199 | ||
200 | if(y > 1752) | |
201 | d += 3; | |
202 | ||
203 | return(d%7); | |
204 | } |