day-70.sh - day-70 - Files related to Day 70, official gopher holy-day
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day-70.sh (842B)
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1 #!/bin/sh
2
3 # day-70.sh
4 #
5 # Find the 70th day of a given year
6 #
7 # Author: ROYGBYTE
8 # Date: 2023
9
10 leap_year() {
11 year=${1}
12 rule_1=$((year%4))
13 if [ ! $rule_1 -eq 0 ]; then
14 # Not divisable by 4, no leap.
15 return 1
16 fi
17 rule_2=$((year%100))
18 rule_3=$((year%400))
19 if [ $rule_2 -eq 0 ]; then
20 # Divisable by 100, maybe leap.
21 if [ ! $rule_3 -eq 0 ]; then
22 # Not divisable by 400, no leap.
23 return 1
24 fi
25 fi
26 return 0
27 }
28
29 # 70th day of year fluctuates depending on whether it's leap year or no.
30 nth_day_march=11
31 leap_year ${1}
32 if [ $? -eq 0 ]; then
33 nth_day_march=10
34 fi
35
36 # Sanity check: day num should be 70, duh.
37 date_string="${1}-03-${nth_day_march}"
38 day_num=$(date --date="${date_string}" +%j)
39 if [ ! $day_num -eq 70 ]; then
40 printf "Something went wrong\n"
41 exit 1
42 fi
43
44 # Pretty print the date information
45 date --date="${date_string}"