1
00:00:06,528 --> 00:00:10,195
- All right, let me
create this file, users.

2
00:00:11,250 --> 00:00:13,980
And in this file, users,

3
00:00:13,980 --> 00:00:17,556
let me enter all that we need.

4
00:00:17,556 --> 00:00:20,556
(keyboard clacking)

5
00:00:26,460 --> 00:00:28,080
Something like this.

6
00:00:28,080 --> 00:00:30,450
It's all about text patterns here.

7
00:00:30,450 --> 00:00:33,960
And first we are going to use grep

8
00:00:33,960 --> 00:00:36,900
to filter all lines that
contain the text, "anna."

9
00:00:36,900 --> 00:00:39,060
So grep anna on users,

10
00:00:39,060 --> 00:00:40,140
and what do we get?

11
00:00:40,140 --> 00:00:40,973
There we go.

12
00:00:40,973 --> 00:00:43,470
And you can see that the
text that we were looking for

13
00:00:43,470 --> 00:00:45,330
is indicated in red.

14
00:00:45,330 --> 00:00:48,060
That's the grep --colors option

15
00:00:48,060 --> 00:00:49,800
that has been set as a default option

16
00:00:49,800 --> 00:00:51,390
doing that for us.

17
00:00:51,390 --> 00:00:53,220
So next, we need to use
the appropriate tool

18
00:00:53,220 --> 00:00:55,650
to print the last line
only from this file.

19
00:00:55,650 --> 00:00:59,700
That will be tail -n on users.

20
00:00:59,700 --> 00:01:00,780
Small detail.

21
00:01:00,780 --> 00:01:02,970
In older versions of tail and head,

22
00:01:02,970 --> 00:01:06,510
you needed tail -n followed by the number

23
00:01:06,510 --> 00:01:08,280
to print the last line,

24
00:01:08,280 --> 00:01:11,340
but in newer versions you don't
have to use the -n anymore,

25
00:01:11,340 --> 00:01:14,400
you can just use minus
followed by the number.

26
00:01:14,400 --> 00:01:16,230
Next, we print the contents of this file

27
00:01:16,230 --> 00:01:18,360
on the screen in reversed order.

28
00:01:18,360 --> 00:01:19,590
That will be tac.

29
00:01:19,590 --> 00:01:21,060
So tac users,

30
00:01:21,060 --> 00:01:24,900
and there we go, contents of
the file in the opposite order.

31
00:01:24,900 --> 00:01:25,733
And that's all.