Linux basic commands

How to redirect the matter of files in a new file

Create two file and write some text in them.

$cat > one

This is first file

$cat > second

This is second file

Now we will combine these two files in a single file. In standard linux its call redirection of output.

$cat one second > new

$cat new

This is first file

This is second files

How to execute multiple commands in a single row

 $[command] ; [command] ; [command] ;[command]…….. To execute multiple commands from single row use a ; between them form example
 $cat new ; mkdir xyz ; mkdir rat ; lsThis is first fileThis is second filesnew xyz rat

How to create multiple sub directory form single command

To create multiple sub directory from a single command use –p switch with mkdir command for example

$mkdir –p a/b/c/d/f/g/h/i/j

In this example we created 9 subdirectories form a single mkdir command. Now verify it by listing.

How to move multiple file in directory with a single commands?

Give all files name one by one with a single space between them and in the end give the destination directory name for example

$mv new first second xyz

how to take back-up and restore files and directories.

tar command is used to take the back up with –cvf switches and the same tar command is used to restore the matter with –xvf switches. For example
 $tar –cvf backup.tar xyz

$tar –xvf backup.tar

How to compress files to save disk space?

Create a large file and check how much disk space is consumed by this file
 $man ls > manoj$du –h manoj12k manoj File manoj is using 12k space on hard disk. For exam prospective you should familiar with two compress utilities.
 $bzip2 [file name]                      {command syntax}$bzip2 manoj$ls$du -h  manoj.bz24k manoj.bz2

$gzip manoj

$ls

manoj.gz

$du –h manoj.gz

4k manoj.gz

$gzip –d manoj.gz

$ls

manoj

Posted in: RHCE