Shell scripts Note 2

Use the date command to convert the Basic time second to year, month, and day:

Command:

Date-d @ 1281161747

Be sure not to forget the symbol "@"

# Obtain the current time by date

# Date-d "-1 week" + % Y % m % d get last week date (day, month, year, hour)

# Date -- date = "-24 hour" + % Y % m % d same as above

Date_now = 'date + % s' shell script to assign variable values

% Output % symbol

% A the abbreviation of the week for the current domain (Sun .. SAT)

% A full weekly write of the current domain (Sunday... Saturday)

% B abbreviated month of the current domain (Jan .. dec)

% B full name of the current domain (January... December)

% C default time format of the current domain (Sat Nov 04 12:02:33 est 1989)

% C n Centennial [00-99]

% D two days (01 .. 31)

% D short time format (mm/DD/yy)

% E short format Day (1 .. 31)

% F file time format same as % Y-% m-% d

% H same as % B

% H hour in 24-hour format (00 .. 23)

% I 12 hour (01 .. 12)

% J the day of the year (001 .. 366)

% K hour in short format in 24-hour format (0 .. 23)

% L hour in 12-hour short format (1 .. 12)

% M double-digit month (01 .. 12)

% M double-digit minutes (00 .. 59)

% N line feed

% N 000000000 S (999999999)

% P indicates the upper afternoon of the current domain in upper case (blank in upper Locales)

% P upper-afternoon indication of the current domain in lower case (blank in lower Locales)

% R 12-hour time representation (hour: minute: Second, double-digit) time, 12-hour (HH: mm: ss [AP] m)

% R 24-hour time representation (hour: minute, double digit) time, 24-hour (HH: mm)

% S number of seconds from the basic time 00:00:00 to the current time (a GNU extension)

% S second (00 .. 60 );

% T horizontal Tab)

% T 24-hour format (HH: mm: SS)

% U indicates the week (from Monday to 7)

% U the week Sunday of the year starts (00 .. 53)

% V The week Monday of the year is the start (01 .. 53)

% W the day of the week starts on Sunday (0 .. 6)

% W the week Monday of the year is the start (00 .. 53)

% X local Date Format (mm/DD/yy)

% X local time format (% H: % m: % s)

% Y two years (00 .. 99)

% Y year (1970 ...)

Example: How many days does it take to write a shell script to calculate its birthday?

Read-P "input your birthday (yyyymmdd):" date1

M = 'date -- date = "$ date1" + % m' # Get the birthday month

D = 'date -- date = "$ date1" + % d' # Get The Birthday Day

Date_now = 'date + % s' # obtain the second value of the current time

Y = 'date + % y' # Get the year of the current time

Birth = 'date -- date = "$ y $ M $ D" + % s' # obtain the second value of this year's birthday date.

Internal = $ ($ birth-$ date_now) # Calculate the interval from today to birthday

If ["$ internal"-lt "0"]; then # determines if today's birthday has passed

Birth = 'date -- date = "$ ($ Y + 1) $ M $ D" + % s' # Get the second value of tomorrow's birthday date

Internal = $ ($ birth-$ date_now) # Calculate the interval from today to the next birthday

Fi

Echo "there is: $ (einternal/60/60/24) days." # output result. seconds are converted to days.

Author "eonbell"