https://linuxengg.com/tac-command-in-linux-with-example/

in this tutorials you can see tac command in Linux with example and this is the best tutorials with all flags. Tac command in the Linux use to concatenate the data and its show the output in reverse order. Tac command show reverse each line , first in the last.

Syntax [option]……[file]…….

Your first command……

I want to say one thing to Linux user, first you should run help command for all commands so that you can understand the flag and you can save your time.

Command: Tac –help

Your next command:

Tac , this command use without any flag, you can see below it use for concatenate the date and reverse the output. First you type tac command and then you type file name which already in your system. In below example you can see txt1 is the file name before the file name we use the tac command

Syntax [option]……[file]…….

command: tac txt1

your first flag -b

tac -b: This option attach the separator before instead of after. In the below example you can see there is two files txt1, txt and we use flag –b . you can see here in the example before start here is space and in the last of the file is separator.

command : tac -b test2 test3

2nd flag: -r

Below option will interpret the separator as a regular expression, here tec command in Linux with example has is two files output without any space or separator. if you use this flag space and separatory will not show in the two files it will will output as stander output.

command: tac -r test2 test3

3rd flag

tac -s, This option use STRING as the separator instead of newline.

command : tac -s test2 test3