Commit | Line | Data |
---|---|---|
816c5586 | 1 | char *sccsid = "@(#)cal.c 4.2 82/02/28"; |
b2c306be BJ |
2 | char dayw[] = { |
3 | " S M Tu W Th F S" | |
4 | }; | |
5 | char *smon[]= { | |
6 | "January", "February", "March", "April", | |
7 | "May", "June", "July", "August", | |
8 | "September", "October", "November", "December", | |
9 | }; | |
10 | char string[432]; | |
11 | main(argc, argv) | |
12 | char *argv[]; | |
13 | { | |
14 | register y, i, j; | |
15 | int m; | |
16 | ||
17 | if(argc < 2) { | |
18 | printf("usage: cal [month] year\n"); | |
19 | exit(0); | |
20 | } | |
21 | if(argc == 2) | |
22 | goto xlong; | |
23 | ||
24 | /* | |
25 | * print out just month | |
26 | */ | |
27 | ||
28 | m = number(argv[1]); | |
29 | if(m<1 || m>12) | |
30 | goto badarg; | |
31 | y = number(argv[2]); | |
32 | if(y<1 || y>9999) | |
33 | goto badarg; | |
34 | printf(" %s %u\n", smon[m-1], y); | |
35 | printf("%s\n", dayw); | |
36 | cal(m, y, string, 24); | |
37 | for(i=0; i<6*24; i+=24) | |
38 | pstr(string+i, 24); | |
39 | exit(0); | |
40 | ||
41 | /* | |
42 | * print out complete year | |
43 | */ | |
44 | ||
45 | xlong: | |
46 | y = number(argv[1]); | |
47 | if(y<1 || y>9999) | |
48 | goto badarg; | |
49 | printf("\n\n\n"); | |
50 | printf(" %u\n", y); | |
51 | printf("\n"); | |
52 | for(i=0; i<12; i+=3) { | |
53 | for(j=0; j<6*72; j++) | |
54 | string[j] = '\0'; | |
55 | printf(" %.3s", smon[i]); | |
56 | printf(" %.3s", smon[i+1]); | |
57 | printf(" %.3s\n", smon[i+2]); | |
58 | printf("%s %s %s\n", dayw, dayw, dayw); | |
59 | cal(i+1, y, string, 72); | |
60 | cal(i+2, y, string+23, 72); | |
61 | cal(i+3, y, string+46, 72); | |
62 | for(j=0; j<6*72; j+=72) | |
63 | pstr(string+j, 72); | |
64 | } | |
65 | printf("\n\n\n"); | |
66 | exit(0); | |
67 | ||
68 | badarg: | |
69 | printf("Bad argument\n"); | |
70 | } | |
71 | ||
72 | number(str) | |
73 | char *str; | |
74 | { | |
75 | register n, c; | |
76 | register char *s; | |
77 | ||
78 | n = 0; | |
79 | s = str; | |
80 | while(c = *s++) { | |
81 | if(c<'0' || c>'9') | |
82 | return(0); | |
83 | n = n*10 + c-'0'; | |
84 | } | |
85 | return(n); | |
86 | } | |
87 | ||
88 | pstr(str, n) | |
89 | char *str; | |
90 | { | |
91 | register i; | |
92 | register char *s; | |
93 | ||
94 | s = str; | |
95 | i = n; | |
96 | while(i--) | |
97 | if(*s++ == '\0') | |
98 | s[-1] = ' '; | |
99 | i = n+1; | |
100 | while(i--) | |
101 | if(*--s != ' ') | |
102 | break; | |
103 | s[1] = '\0'; | |
104 | printf("%s\n", str); | |
105 | } | |
106 | ||
107 | char mon[] = { | |
108 | 0, | |
109 | 31, 29, 31, 30, | |
110 | 31, 30, 31, 31, | |
111 | 30, 31, 30, 31, | |
112 | }; | |
113 | ||
114 | cal(m, y, p, w) | |
115 | char *p; | |
116 | { | |
117 | register d, i; | |
118 | register char *s; | |
119 | ||
120 | s = p; | |
121 | d = jan1(y); | |
122 | mon[2] = 29; | |
123 | mon[9] = 30; | |
124 | ||
125 | switch((jan1(y+1)+7-d)%7) { | |
126 | ||
127 | /* | |
128 | * non-leap year | |
129 | */ | |
130 | case 1: | |
131 | mon[2] = 28; | |
132 | break; | |
133 | ||
134 | /* | |
135 | * 1752 | |
136 | */ | |
137 | default: | |
138 | mon[9] = 19; | |
139 | break; | |
140 | ||
141 | /* | |
142 | * leap year | |
143 | */ | |
144 | case 2: | |
145 | ; | |
146 | } | |
147 | for(i=1; i<m; i++) | |
148 | d += mon[i]; | |
149 | d %= 7; | |
150 | s += 3*d; | |
151 | for(i=1; i<=mon[m]; i++) { | |
152 | if(i==3 && mon[m]==19) { | |
153 | i += 11; | |
154 | mon[m] += 11; | |
155 | } | |
156 | if(i > 9) | |
157 | *s = i/10+'0'; | |
158 | s++; | |
159 | *s++ = i%10+'0'; | |
160 | s++; | |
161 | if(++d == 7) { | |
162 | d = 0; | |
163 | s = p+w; | |
164 | p = s; | |
165 | } | |
166 | } | |
167 | } | |
168 | ||
169 | /* | |
170 | * return day of the week | |
171 | * of jan 1 of given year | |
172 | */ | |
173 | ||
174 | jan1(yr) | |
175 | { | |
176 | register y, d; | |
177 | ||
178 | /* | |
179 | * normal gregorian calendar | |
180 | * one extra day per four years | |
181 | */ | |
182 | ||
183 | y = yr; | |
184 | d = 4+y+(y+3)/4; | |
185 | ||
186 | /* | |
187 | * julian calendar | |
188 | * regular gregorian | |
189 | * less three days per 400 | |
190 | */ | |
191 | ||
192 | if(y > 1800) { | |
193 | d -= (y-1701)/100; | |
194 | d += (y-1601)/400; | |
195 | } | |
196 | ||
197 | /* | |
198 | * great calendar changeover instant | |
199 | */ | |
200 | ||
201 | if(y > 1752) | |
202 | d += 3; | |
203 | ||
204 | return(d%7); | |
205 | } |