Shell脚本在Linux中获取日期

Question

I am new to Shell scripting.

I want to write a script to get any random Date from the user in the format YYYY:MM:DD and echo (display) date of tuesday and friday of previous week.

For Example if I give Input Date as 2013-12-11 .
The output should be

date1= 2013-12-06
date2= 2013-12-10

or

Input Date as 2013-12-07

Output

date1= 2013-12-03
date2= 2013-12-06

Answer 1

Try the following:

input=2013-12-11
lastTues=$(date -d "$input -$(date -d "$input +5 days" +%u) days" +%Y-%m-%d)
lastFri=$(date -d "$input -$(date -d "$input +2 days" +%u) days" +%Y-%m-%d)

This command first works out how many days there are between the input date and last Tuesday (or Friday), call this X . It then runs date -d "inputDate -X days" to calculate the new date.

Answer 2

Perl to the rescue:

#!/usr/bin/perl
use warnings;
use strict;

use DateTime;

sub tuefri {
    my ($year, $month, $day) = split /[^0-9]/, shift;
    my $date = 'DateTime'->new( year  => $year,
                                month => $month,
                                day   => $day,
                              );
    $date->subtract(days => 7);
    my @result;
    until (2 == @result) {
        push @result, $date->ymd if grep $_ == $date->day_of_week, 2, 5;
        $date->add(days => 1);
    }
    return @result
}

my $i = 1;
print 'date', $i++, "= $_\n" for tuefri(shift);

Answer 3

A python solution using the python-dateutil module:

import fileinput
from dateutil.relativedelta import TU, FR, relativedelta
from datetime import date

for line in fileinput.input():
    d = date(*(map(int, line.rstrip().split('-'))))
    print(d + relativedelta(weekday=FR(-1)))
    print(d + relativedelta(weekday=TU(-1)))

Run it like:

python script.py <<<"2013-12-11"

That yields:

2013-12-06
2013-12-10