Shell script arguments: positional parameters

• Positional parameters can be used to pass information to a script: directly, with parameters representing command-line arguments, or indirectly, using set and command substitution (see below), letting the parameters represent the output of a command
• Within the script, we refer to the first argument as $1, the second argument as $2, and so on
• $0 stands for the name of the command itself
• $* stands for all arguments from $1 on up
• These numbered arguments are referred to as positional parameters
• $# represents the number of arguments
• set is used to assign values to positional parameters
  Example:
  set `who am i`
  echo $1
  Note: previously assigned values for positional parameters will be erased!!