Bash Reference Manual - Major Differences From The Bourne Shell Go to the first , previous , next , last section, table of contents . Several of the Bash builtins take options to act on arrays.
Bash provides a number of built-in array variables.
Very useful when an if statement needs to act only if a test fails. Variables present in the shell's initial environment are automatically exported to child processes. The Bourne shell does not normally do this unless the variables are explicitly marked using the export command. See section Bash Variables , for details. This closes a longstanding shell security hole.