I had nothing to do and wanted to write a script to convert the Gregorian to the Lunar New Year in Linux using shell. It was finally done intermittently for about a week. Now let’s take it out and share it with you.
1. Reason
The implementation principle of this script is table lookup method (because there is an error in the formula); based on the Lunar New Year, two different Lunar New Year are calculated.
Before writing this script, I wanted to add the Gregorian calendar and lunar calendar dates to the Linux terminal command prompt. There is Lunar software in Ubuntu to obtain lunar dates, but there is no similar software in Fedora or CentOS, so I want to implement one by myself, but I have written a lot in other languages online, so it is not necessary to write it again. So I want to write one in a shell.
2. Functions and usage
Function: Convert specific solar calendar dates to lunar dates.
Time range: 1901~2099, corresponding to the lunar year period is 4598~4796
Parameter format (no parameters default to the current system date): yyyymmdd
As January 1, 2013:
$./ 20130101
4709-11-20
3. Complete data
Complete data download link:
http://xiazai./201408/tools/lunar-20131202.7z
Files in the package:
Main script, specific implementation
datebases Lunar metadata
Change log
readme script instructions and precautions
The main script code is as follows:
#!/bin/sh
DATE=$@
[ "$DATE" = "" ] && DATE=$(date +%Y%m%d)
databases_path=databases
date_year=$(echo $DATE |sed 's/^\(.\{4\}\).*/\1/')
date_month=$(echo $DATE |sed 's/.*\(..\)..$/\1/')
date_day=$(echo $DATE |sed 's/.*\(..\)$/\1/')
date_days=$(date -d $DATE +%j)
lunar_year=$(sed /$date_year/!d $databases_path |sed 's/^\(....\).*/\1/')
lunar_year_data=$(sed /$date_year/!d $databases_path |sed 's/.*\ \(.*\)/\1/')
lunar_year_data_bin=$(echo "ibase=16;obase=2;$lunar_year_data"|bc |sed -e :a -e 's/^.\{1,23\}$/0&/;ta')
new_year_month_bin=$(echo $lunar_year_data_bin |sed -e 's/^.\{17\}\(.\{2\}\).*/\1/')
new_year_month=$(echo "ibase=2;$new_year_month_bin"|bc |sed -e :a -e 's/^.\{1,1\}$/0&/;ta')
new_year_day_bin=$(echo $lunar_year_data_bin |sed -e 's/.*\(.\{5\}\)$/\1/')
new_year_day=$(echo "ibase=2;$new_year_day_bin"|bc |sed -e :a -e 's/^.\{1,1\}$/0&/;ta')
new_year_days=$(date -d $date_year$new_year_month$new_year_day +%j)
lunar_days=$(expr $date_days - $new_year_days + 1)
befor_or_after=0
if [ "$lunar_days" -le "0" ]; then
befor_or_after=1
date_year=$(($date_year - 1))
lunar_year=$(sed /$date_year/!d $databases_path |sed 's/^\(....\).*/\1/')
lunar_year_data=$(sed /$date_year/!d $databases_path |sed 's/.*\ \(.*\)/\1/')
lunar_year_data_bin=$(echo "ibase=16;obase=2;$lunar_year_data"|bc |sed -e :a -e 's/^.\{1,23\}$/0&/;ta')
fi
lunar_leap_month_bin=$(echo $lunar_year_data_bin |sed -e 's/^\(.\{4\}\).*/\1/')
lunar_leap_month=$(echo "ibase=2;$lunar_leap_month_bin"|bc)
lunar_month_all_bin=$(echo $lunar_year_data_bin |sed -e 's/^.\{4\}\(.\{13\}\).*/\1/')
[ "$lunar_leap_month" = "0" ] && lunar_month_all_bin=$(echo $lunar_year_data_bin |sed -e 's/^.\{4\}\(.\{12\}\).*/\1/')
lunar_month_all=$(echo $lunar_month_all_bin |sed -e 's/0/29\ /g' |sed -e 's/1/30\ /g')
if [ "$befor_or_after" = "0" ];then
lunar_month=1
lunar_day=$lunar_days
for i in $lunar_month_all
do
[ "$lunar_day" -gt "$i" ] && lunar_day=$(($lunar_day - $i)) && lunar_month=$(($lunar_month + 1))
[ "$lunar_day" = "$i" ] && break
done
else
lunar_month=12
lunar_day=$((-$lunar_days))
lunar_month_all_bin=$(echo $lunar_month_all_bin |rev)
lunar_month_all=$(echo $lunar_month_all_bin |sed -e 's/0/29\ /g' |sed -e 's/1/30\ /g')
for i in $lunar_month_all
do
if [ "$lunar_day" -gt "$i" ]; then
lunar_day=$(($lunar_day - $i))
lunar_month=$(($lunar_month - 1))
else
lunar_day=$(($i - $lunar_day))
break
fi
done
fi
if [ "$lunar_leap_month" = "0" ]; then
echo $lunar_year-$lunar_month-$lunar_day
else
if [ "$lunar_leap_month" -ge "$lunar_month" ]; then
echo $lunar_year-$lunar_month-$lunar_day
elif [ "$befor_or_after" = "0" ]; then
if [ "$(($lunar_leap_month + 1))" = "$lunar_month" ];then
lunar_month=$(($lunar_month - 1))
echo $lunar_year-*$lunar_month-$lunar_day
else
lunar_month=$(($lunar_month - 1))
echo $lunar_year-$lunar_month-$lunar_day
fi
else
echo $lunar_year-$lunar_month-$lunar_day
fi
fi
4 Modify history
2013-12-02
Bug found: If the last month of the lunar calendar is the big month and this month is the small month, then the output of the thirty of the previous month is the first day of the month. The reason is that there are 30 days left last month, which is exactly the thirty of the previous month, and this month is 29 days, 29<30. The next cycle is the number of days of the month, making the thirty of the previous month the first day of the month.
Bug modification: Add judgment statement, if the remaining days in the lunar calendar are equal to the number of days in the current month, no longer loops