What is the difference between $@ and $*?

The difference between $@ and $* lies in how they handle quoted arguments when used in a script.

1. $@:

   • When used without quotes, it behaves like $*, treating each argument as a separate word.
   • When used with quotes ("$@"), it preserves each argument as a separate entity. This means that if any arguments contain spaces, they will be treated as individual arguments.

   Example:

   #!/bin/bash
   echo "Using \$@:"
   for arg in "$@"; do
       echo "$arg"
   done

   If you run the script with ./script.sh "arg 1" "arg 2", the output will be:

   Using $@:
   arg 1
   arg 2

2. $*:

   • When used without quotes, it behaves like $@, treating all arguments as a single word.
   • When used with quotes ("$*"), it combines all arguments into a single string, with the first character of the IFS (Internal Field Separator, usually a space) used as a separator.

   Example:

   #!/bin/bash
   echo "Using \$*:"
   for arg in "$*"; do
       echo "$arg"
   done

   If you run the script with ./script.sh "arg 1" "arg 2", the output will be:

   Using $*:
   arg 1 arg 2

In summary, use "$@" when you want to preserve the individual arguments, especially if they contain spaces, and use "$*" when you want to treat all arguments as a single string.