37.3. Bash, version 4

Chet Ramey announced Version 4 of Bash on the 20th of February, 2009. This release has a number of significant new features, as well as some important bugfixes.

Among the new goodies:

37.3.1. Bash, version 4.1

Version 4.1 of Bash, released in May, 2010, was primarily a bugfix update.

37.3.2. Bash, version 4.2

Version 4.2 of Bash, released in February, 2011, contains a number of new features and enhancements, in addition to bugfixes.



To be more specific, Bash 4+ has limited support for associative arrays. It's a bare-bones implementation, and it lacks the much of the functionality of such arrays in other programming languages. Note, however, that associative arrays in Bash seem to execute faster and more efficiently than numerically-indexed arrays.


Copyright 1995-2009 by Chester Ramey.


This only works with pipes and certain other special files.


But only in conjunction with readline, i.e., from the command-line.


And while you're at it, consider fixing the notorious piped read problem.