2.Understand and use essential tools - RHEL7

Access a shell prompt &  issue commands with correct syntax.


Login to your Linux System

use Putty console or the terminal to access the shell prompt

Now, let’s check the command syntax.


To issue commands with the correct syntax always consult the man command for the command

For example, run the man command for ls

# man ls


Use input-output redirection (>, >>, |, 2>, etc.).

Output Redirection

the notation > file    normally writes the command  output to standard output / file

# echo  cats  > cats.txt
# ls  > listing.txt

note with the above notation if the file is not empty then the command will rewrite your file contents.

the notation >>  file  normally writes the command  output to standard output / file

echo  cats  >> cats.txt

ls  >>  listing.txt

# echo  cats  >> cats.txt
# ls  >> listing.txt

The difference between this operator is that if the file is empty it will write the data to the last line and it will not rewrite the file.

The Operator |

Takes output from one program, or process, and sends it to another program or process.


listing all the contents of a directory then taking the output and pass it to the cut command to process  the delimiter t and grab the first field string.

ls -al  | cut -d “t” -f1

The operator 2>

Represents is standard error output (STDERR).

sh script.sh 2> /dev/null

Input Redirection

the less-than character < is used to redirect the input of a command.

Use grep and regular expressions to analyze text.

cat << EOF This is a text for  input redirection EOF

Access remote systems using ssh.

Log in and switch users in multiuser targets.

Archive, compress, unpack, and uncompress files using tar, star, gzip, and bzip2.

Create and edit text files.

Create, delete, copy, and move files and directories.

  • Create a file

# touch filename

  • Create a directory

# mkdir directoryname

Create hard and soft links.

List, set, and change standard ugo/rwx permissions.

Locate, read, and use system documentation including man, info, and files in /usr/share/doc.