Shell

Bash Guide for Beginners

The Architecture of Open Source Applications: The Bourne-Again Shell

• Environment variables

• Lexical analysis

  • Split input into tokens

• Parse (analyze and substitute) the tokens into commands

• Command Execution

  • Word expansion

    • Environment variables substitution

    • Field splitting

    • Quote removal

  • Redirection of I/O

  • Pipelines

  • Built-in commands

    • echo with option '-n'

    • cd with relative or absolute path

    • pwd

    • export

    • unset

    • env without arguments

    • exit

  • Execution of non-built-in commands

  • Exit status of last command

  • Signals: SIGINT (CTRL-C), SIGQUIT (CTRL-\) and EOF (CTRL-D)