paste

Insert lines from files using Linux paste command:

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Input files:

$ cat contestant.txt

Christopher

Williams

Darwin

Ajay

Brain

Amay

Jiten

Lila

$ cat leader.txt

Mr B

Mrs C

Mrs A

Output required:

For every single line of 'leader.txt'; insert 3 lines from file 'contestant.txt'; so that the output looks like this:

Mr B

Christopher

Williams

Darwin

Mrs C

Ajay

Brain

Amay

Mrs A

Jiten

Lila

The step by step solution using Linux/UNIX paste command

$ cat contestant.txt | paste - - -

Output:

Christopher     Williams        Darwin

Ajay    Brain   Amay

Jiten   Lila

$ cat contestant.txt | paste - - - | paste leader.txt -

Output:

Mr B    Christopher     Williams        Darwin

Mrs C   Ajay    Brain   Amay

Mrs A   Jiten   Lila

$ cat contestant.txt | paste - - - |paste leader.txt - |tr "\t" "\n"

Output:

Mr B

Christopher

Williams

Darwin

Mrs C

Ajay

Brain

Amay

Mrs A

Jiten

Lila

du,df

Directory size excluding sub-directories - Linux:

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Directory '/home/user/work/demo/' contains a few regular files and two directories say "part2"(size=41236 KB) and "libs"(size=20620 KB).

$ du ~/work/demo/

41236   /home/user/work/demo/part2

20620   /home/user/work/demo/libs

87640   /home/user/work/demo/

From Linux/UNIX DU(1) command man page:

-s, --summarize

display only a total for each argument.

So, the following command is going to display the total size of the directory '/home/user/work/demo/'

$ du -s ~/work/demo/

87640   /home/user/work/demo/

Now, if you need to find the size of the '/home/user/work/demo/' directory excluding the size of the sub-directories, there is a command line option with DU(1):

-S, --separate-dirs

do not include size of sub-directories

So

$ du -S ~/work/demo/

41236   /home/user/work/demo/part2

20620   /home/user/work/demo/libs

25784   /home/user/work/demo/

Now,

$ du -S --max-depth=0 ~/work/demo/

25784   /home/user/work/demo/

or

$ du -S ~/work/demo/ | awk 'END {print}'

25784   /home/user/work/demo/

awk

please refer my another blog : Top examples of awk command in unix