echo

echo command prints a string or a environment variable

Example:

echo $HOME

echo Hello, World

Frequently used shell variables

• $USERNAME
• $HOME
• $HOSTNAME
• $PWD
• $PATH

Special shell variables

• $0

  • Name of the shell

• $$

  • Process ID (PID) of the shell

    

• $? → Return code of previously run program

• $- → Flags set in the bash shell

Process control

• Use of & to run a job in the background
• fg
• coproc