mirror of
https://git.FreeBSD.org/ports.git
synced 2024-11-14 23:46:10 +00:00
6a68b60f92
A Unix shell embedded into Scheme, with access to all Posix calls Reviewed by: max Submitted by: cracauer@cons.org "Martin Cracauer"
85 lines
3.5 KiB
Plaintext
85 lines
3.5 KiB
Plaintext
Scsh is a Unix shell in that is has significant syntax entensions to
|
|
make writing Unix shell scripts easy (constructing pipelines, setting
|
|
I/O redirection, conditional execution etc.). It also offers access to
|
|
lower-level functionality like all Posix system calls, TCP/IP sockets
|
|
and a full-featured regular expression library. All this is embedded
|
|
into a general-purpose programming language with proper handling of
|
|
quoting, real data types and extensive, syntactically clean control
|
|
constructs.
|
|
|
|
Scsh is also a full implementation of R4RS Scheme with some
|
|
non-standard behaviour (required for scripting) that shouldn't be a
|
|
problem in practice. As a result, a wide varity of exsting Scheme code
|
|
can be used.
|
|
|
|
Offered functionality:
|
|
- Scheme special forms to work with Unix commands and command chains
|
|
- the ability to be used to write self-identifying scripts with
|
|
'#!/usr/local/bin/scsh' as the first line.
|
|
- all Posix system calls including signals, tty and time handling
|
|
- regular expressions, uses the same C library as *BSD, returns a
|
|
proper structure describing the matches and/or matched substrings.
|
|
- delimited strings, awk-like record/field processing
|
|
- several socket layers
|
|
- A foreign function interface to use other C code, including a tool
|
|
(cig) to automate integration process.
|
|
- elisp code to run it as a subprocess under emacs
|
|
- On the Scheme side: a module system, basic thread support, optional
|
|
static linker (compiles images to C, then into an executable).
|
|
|
|
The underlying Scheme implementation is a virtual machine for compact
|
|
byte code.
|
|
|
|
Installed Items:
|
|
----------------
|
|
|
|
Main program name(s): "scsh"
|
|
Manpage(s): scsh(1)
|
|
Info files: <none>
|
|
Other documentation: lib/scsh/doc/ (also linked to share/doc/scsh)
|
|
Learning entry point: lib/scsh/doc/scsh-paper.ps or
|
|
http://www-swiss.ai.mit.edu/scsh/
|
|
|
|
General Notes:
|
|
--------------
|
|
|
|
Changing ${PREFIX} to something other than /usr/local works
|
|
flawlessly, as far as scsh itself is concerned (that means: it will
|
|
run and find everythings it needs). You will have to change the
|
|
initial "#!/usr/local/bin/scsh" line when running shell scripts, of
|
|
course. An additional problem is the location of optional packages
|
|
like slib, these are still expected to be in /usr/local. I looked
|
|
into the sources and all the hardcoded /usr/local I found are in files
|
|
that are installed sourcecode form when scsh is installed
|
|
(i.e. slib-init.scm).
|
|
|
|
To load slib, install slib into /usr/local/lib/slib and run
|
|
(load "slib-init.scm")
|
|
in scsh. It requires no additional setup (paths or such).
|
|
|
|
The emacs interface is in the original distribution in emacs/. For
|
|
documentation see doc/user-quide.txt.
|
|
|
|
Differences between FreeBSD port and generic scsh release:
|
|
----------------------------------------------------------
|
|
|
|
1) When hitting C-d (end-of-file), scsh asks 100 times for
|
|
confirmation. I changed the default to do this just once. See constant
|
|
*y-or-n-eof-count* in scsh/rw.scm to change it.
|
|
|
|
2) The original scsh sends a mail to the scsh authors everytime you
|
|
make the package. The FreeBSD port doesn't. The authors of scsh would
|
|
appreciate it if you do a `(cd work/scsh-0.4.4 && make .notify)` after
|
|
you build this package.
|
|
|
|
3) A symbolic link ${PREFIX}/share/doc/scsh to the documentation is
|
|
created.
|
|
|
|
4) Some basic description text files from the distribution base dir
|
|
are copied to lib/doc. The emacs directory is copied into
|
|
lib/scsh/emacs. scsh's default is not to install these files.
|
|
|
|
5) Some /usr/tmp -> /var/tmp
|
|
|
|
FreeBSD port provided by Martin Cracauer <cracauer@cons.org>
|