Shell Scripting Tutorial-3: View System Date; Calendar Video Lecture | Shell Scripting: Discovering to Automate Command-Line Tasks - Back-End Programming

hello guys my name is Mathur and welcome
to my channel this is the third tutorial
in the series of tutorials on UNIX shell
programming now in this tutorial we are
going to check out two really important
commands the first command is the Cal
command and it is used to view the
calendar so if I type in CL and press
Enter
I would see the calendar of the current
month and obviously the current year so
its May 2012 and the current day is
highlighted now the Cal command is a
pretty important command and when we
learn shell scripting we would put it to
use in different ways now if suppose you
want to view the calendar of not the
current month part of some month from
the past or someone from the future for
example if I want to view the calendar
of July 2006 then what I would have to
do is type in Cal and then follow that
up with a space and then since July is
the seventh month I have to type in
seven and then the year which in this
example we will take 2006 and then press
enter and there you go
I can see that the calendar of July 2006
is displayed now this is a format that
you have to obey you cannot type in the
year first like 2003 April if you would
do that then it will show an error
message saying the 2003 is neither a
month number nor a name now this brings
us to an interesting observation this is
and you know this brick Springs us to a
very important point if suppose I do not
want to type in a number for my month
but if I want to type in the name I can
do that as well but I don't even have to
type in the full name for example if I
want to view the calendar of February
two thousand thirty three then I can
just type in Fe P and that would be
taken as February and then the year 2000
oops sorry
2033 in that press enter and I can see
the calendar of 2033 February okay it's
not a leap year
it cannot be so that was enough about
Cal command the next command that we're
going to check out is the date come on
now when I type in date and press enter
I see the current date and it gives me a
lot of information firstly it tells me
what day it is it's Sunday and what
month is it it's May and then it tells
me the date which is it's the 28th day
of the month and then it tells me the
time at 6:48 a.m. in the morning and it
tells me my time zone which is ist
Indian Standard Time and it also tells
me the year so date is a pretty good
utility and it gives a output which is
quite comprehensive but what if you want
to view the date in a custom format not
in the format in which it is being
displayed correctly but in your own
format you can do that and this is how
you do it
you first type in date and then you give
space and use single quotation mark and
press the addition symbol or the plus
symbol and then you can basically design
your own custom format for example if I
first want to type in the string date
now see this is the optional part this
is not a part of the command so this can
be in uppercase letters right and if I
then want to put a colon and then if I
suppose want to just see the month and a
hyphen and the year I would have to use
percentage symbol for small m and small
m which are symbols for month and year
respectively and then suppose if I want
to see the time but I want to see the
time on and
uline I'll have to use a percentage n
which basically would tell the shell to
display the time on a new line and then
I can type in time and then follow it up
with another colon and then view it in
what format ours minutes and seconds all
right that would be fine so ours colon
percentage capital M 4 minutes and colon
percentage capital S 4 seconds and then
I can close my format width ending
single quotation mark and press ENTER
and I can see my date and time being
displayed in custom format now this can
be used and can also be avoided and we
would see different ways of displaying
date and custom formats later on when we
get to shell scripting but for the time
being I just wanted to give you guys
some insight about date and gas so I
created this tutorial anyway in the next
tutorial we'll be checking out a few
more important commands so please stick
with me and I hope this isn't getting
boring and yeah that's pretty much it
I'll see you guys in the next tutorial
please subscribe to my channel thank you
so much for watching