Pipe Command:

• | = Pipe command = Pipes the output of the previous command as an input to the next command

Less Command:

• less [filename] = Displays the contents of a file or a command output, one page at a time. And allows to navigate forward and backward through the file

Different piping examples/use cases:

• cat /var/log/syslog | less = Pipes the output of 'syslog' file to less program.
• ls /usr/bin | less = Pipes the output of ls command to less program.
• history | less = Pipes the output of history command to less program.

Pipe & Grep:

Grep Command:

• grep [pattern] = Searches for a particular pattern of characters and displays all lines that contain that pattern

More piping examples/use cases:

• history | grep sudo = Look for any commands of history commands, which have 'sudo' word in it
• history | grep "sudo chmod" = Look for any commands of history commands, which have 'sudo chmod' phrase in it
• history | grep sudo | less = History output will pass output to grep and filter for 'sudo' and this output will again be piped or passed to less program
• ls /usr/bin/ | grep java = Filter ls output for java
• cat Documents/java-app/config.yaml | grep ports = See all 'ports' occurences in config.yaml file

Redirects in Linux:

• > = Redirect Operator = Takes the output from the previous command and sends it to a file that you give

Different redirects examples/use cases: