Showing posts with label time format. Show all posts
Showing posts with label time format. Show all posts

Sunday, August 25, 2013

HowTo Format Date For Display or Use In a Shell Script

How do I format date to display on screen on for my shell scripts as per my requirements on Linux or Unix like operating systemsYou need to use the standard date command to format date or time. You can use the same command with the shell script.
 The syntax is
  1. date +FORMAT 
  2. date +"%FORMAT"
  3. date +"%FORMAT%FORMAT" 
  4. date +"%FORMAT-%FORMAT"

Task: Display date in mm-dd-yy format

Open a terminal and type the following date command:
$ date +"%m-%d-%y"Sample output:
02-27-07
To turn on 4 digit year display:
$ date +"%m-%d-%Y"Just display date as mm/dd/yy format:
$ date +"%D"

Task: Display time only

Type the following command:
$ date +"%T"Outputs:
19:55:04
To display locale's 12-hour clock time, enter:
$ date +"%r"Outputs:
07:56:05 PM
To display time in HH:MM format, type:
$ date +"%H-%M"Sample outputs:
00-50

How do I save time/date format to the shell variable?

$ NOW=$(date +"%m-%d-%Y"To display a variable use echo / printf command:
$ echo $NOW

A sample shell script

#!/bin/bash
NOW=$(date +"%m-%d-%Y")
FILE="backup.$NOW.tar.gz"
echo "Backing up data to /nas42/backup.$NOW.tar.gz file, please wait..."
# rest of script
# tar xcvf /nas42/backup.$NOW.tar.gz /home/ /etc/ /var
 

A complete list of FORMAT control characters supported by the date command

FORMAT controls the output. It can be the combination of any one of the following:
%FORMAT StringDescription
%%a literal %
%alocale's abbreviated weekday name (e.g., Sun)
%Alocale's full weekday name (e.g., Sunday)
%blocale's abbreviated month name (e.g., Jan)
%Blocale's full month name (e.g., January)
%clocale's date and time (e.g., Thu Mar 3 23:05:25 2005)
%Ccentury; like %Y, except omit last two digits (e.g., 21)
%dday of month (e.g, 01)
%Ddate; same as %m/%d/%y
%eday of month, space padded; same as %_d
%Ffull date; same as %Y-%m-%d
%glast two digits of year of ISO week number (see %G)
%Gyear of ISO week number (see %V); normally useful only with %V
%hsame as %b
%Hhour (00..23)
%Ihour (01..12)
%jday of year (001..366)
%khour ( 0..23)
%lhour ( 1..12)
%mmonth (01..12)
%Mminute (00..59)
%na newline
%Nnanoseconds (000000000..999999999)
%plocale's equivalent of either AM or PM; blank if not known
%Plike %p, but lower case
%rlocale's 12-hour clock time (e.g., 11:11:04 PM)
%R24-hour hour and minute; same as %H:%M
%sseconds since 1970-01-01 00:00:00 UTC
%Ssecond (00..60)
%ta tab
%Ttime; same as %H:%M:%S
%uday of week (1..7); 1 is Monday
%Uweek number of year, with Sunday as first day of week (00..53)
%VISO week number, with Monday as first day of week (01..53)
%wday of week (0..6); 0 is Sunday
%Wweek number of year, with Monday as first day of week (00..53)
%xlocale's date representation (e.g., 12/31/99)
%Xlocale's time representation (e.g., 23:13:48)
%ylast two digits of year (00..99)
%Yyear
%z+hhmm numeric timezone (e.g., -0400)
%:z+hh:mm numeric timezone (e.g., -04:00)
%::z+hh:mm:ss numeric time zone (e.g., -04:00:00)
%:::znumeric time zone with : to necessary precision (e.g., -04, +05:30)
%Zalphabetic time zone abbreviation (e.g., EDT)
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