Es is an extensible shell. The language was derived from the Plan 9 shell, rc, and was influenced by functional programming languages, such as Scheme, and the Tcl embeddable programming language. This implementation is derived from Byron Rakitzis's public domain implementation of rc.
See the INSTALL file for installation instructions. Once it's running have a look at the manual page and the docs and examples directories, in particular Haahr & Rakitzis's paper: ``Es: a shell with higher-order functions.'' The paper corresponds to a slightly older version of the shell; see the file ERRATA for changes which affect parts of the paper.
The file initial.es, which is used to build the initial memory state of the es interpreter, can be read to better understand how pieces of the shell interact.
The official ftp site (associated with the original authors) is at:
ftp://ftp.sys.utoronto.ca/pub/es
but all of the relevant information is mirrored in the repository and/or the website:
http://www.github.com/wryun/es-shell
http://wryun.github.io/es-shell
including the change history and the old mailing list archives.
An old version of Paul's .esrc (es startup) file is provided as an example as esrc.haahr; correctness is not guaranteed. A simple debugger for es scripts, esdebug, is also included; this is very untested and should be considered little more than a sketch of a few ideas.
Es is in the public domain. We hold no copyrights or patents on the source code, and do not place any restrictions on its distribution. We would appreciate it if any distributions do credit the authors.
Enjoy!
-- Paul Haahr & Byron Rakitzis
Maintenance by:
- Soren Dayton (0.9beta1)
- James Haggerty (post 0.9beta1)
