13.14. Order of Expansion

When you are performing the expansion of variables, commands, arithmetic expressions, and pathnames, the shell is programmed to follow a specific order when scanning the command line. Assuming that the variables are not quoted, the processing is performed in the following order:

1. Brace expansion

2. Tilde expansion

3. Parameter expansion

4. Variable substitution

5. Command substitution

6. Arithmetic expansion

7. Word splitting

8. Pathname expansion