Scsh is a unix shell embedded in Scheme. What does that mean? Well, unix shells are powerful tools. They allow a user to concisely specify her commands and the communications between them (piping, redirecting, &c.). When she needs to do something more complex than running a set of commands with known inputs, however, things become complicated. General programming with sh can be unpleasant and error prone, to say the least.
Scheme is a simple, expressive general programming language. A user with some taste may want to use it to wield her computing machine. For simple commands, however, it is not the most concise. At the scale of the command line, even the overhead of parentheses matters. It would be nice to use each of these languages where their strengths lie.
Scsh is the solution. It allows the user to write commands in a language within Scheme that follows the unix way, but also allows her to specify more complex commands with the elegance of Scheme.
In order to run scsh, you'll need to be running on a POSIX complient operating system, the gnu build system, and (until its next release) the latest development revision of scheme48 at http://s48.org/cgi-bin/hgwebdir.cgi/s48.
In order to build the development version of scheme48, you'll need to have an installed version of the latest released version. If it's not available in your operating system's package managing system, the source distribution and installation instructions are available here http://s48.org/1.8/download.html.
Two different versions of scheme48 can't be installed to the same prefix without file conflicts. To
avoid this problem, either install the development version to a different prefix than the latest
released version, or uninstall that version right before you execute the
make install step below.
If you choose the former method, make sure the chosen prefix's bin directory comes before the latest
released version's prefix's bin directory in your PATH variable. This way, the command
will be resolved to the development version.
In a fresh clone of the scheme48 development repository
hg clone http://www.s48.org/cgi-bin/hgwebdir.cgi/s48) run the following commands
$ ./autogen.sh $ ./configure $ make $ make install
Within a fresh checkout of scsh, run the following commands
$ git submodule update --init $ autoreconf $ ./configure $ make
That'll pull all the scheme dependencies and build scsh. To try scsh before installing, run
from that same directory. That'll open up a repl with standard r5rs scheme in the environment,
scsh's command language, and a large posix library (docs to come). To run scsh's test suite, run
make install to install scsh on your system. Standard gnu build system rules apply. So, for
instance, if you'd like to install to a location other than the default (usually
./configure the appropriate flags.