Shell Scripting Features

     Command features

• >     :-   Redirect output
• >>   :-   Append to file
• <     :-   Redirect input
• <<   :-   "Here" document (redirect input)
• |       :-   Pipe output
• &     :-   Run process in background.
• ;       :-   Separate commands on same line
• *      :-   Match any character(s) in filename
• ?      :-   Match single character in filename
• [ ]    :-   Match any characters enclosed
• ( )    :-   Execute in subshell
• ` `    :-   Substitute output of enclosed command
• " "   :-    Partial quote (allows variable and command expansion)
• ' '     :-    Full quote (no expansion)
• \      :-    Quote following character
• $var :-    Use value for variable
• $$    :-    Process id
• $0    :-    Command name
• $n    :-    nth argument (n from 0 to 9)
• $*    :-    All arguments as a simple word
• #      :-    Begin comment
• bg    :-    Background execution
• break :-   Break from loop statements
• cd    :-     Change directories
• cont :-     Resume a program loop
• echo :-    Display output
• eval  :-    Evaluate arguments
• exec :-    Execute a new shell
• fg    :-     Foreground execution
• jobs :-     Show active jobs
• kill   :-    Terminate running jobs
• newgrp :-  Change to a new group
• shift  :-      Shift positional parameters
• stop  :-     Suspend a background job
• suspend :- Suspend a foreground job
• time   :-    Time a command
• umask :-   Set or list file permissions
• unset  :-    Erase variable or function definitions
• wait   :-    Wait for a background job to finish