Scsh 0.6.6 Release notes -*- outline -*- We are pleased to release scsh version 0.6.6. The main focus of this release is support for the upcoming packaging proposal and the removal of any code which did not conform to scsh's BSD-style license. In addition, some bugs have been fixed. The text below gives a general description of scsh, instructions for obtaining it, pointers to discussion forums, and a description of the new features in release 0.6.6. (Emacs should display this document is in outline mode. Say c-h m for instructions on how to move through it by sections (e.g., c-c c-n, c-c c-p).) * Contents ========== What is scsh Scsh as a scripting language Scsh as a systems-programming language Scsh is a portable programming environment Obtaining and installing scsh Getting in touch The World-Wide What? New in this release Removed or replaced non-free code New code for sorting Separate documentation of the library directories search facility New module CONFIGURE Argument processing more robust Ultrix is no longer supported Bug fixes New in 0.6.5 New in 0.6.4 New in 0.6.3 New in 0.6.2 New in 0.6.1 New in 0.6.0 Thanks * What is scsh ============== Scsh is a broad-spectrum systems-programming environment for Unix embedded in R5RS Scheme. It has an open-source copyright, and runs on most major Unix systems. ** Scsh as a scripting language ------------------------------- Scsh has a high-level process notation for doing shell-script like tasks: running programs, establishing pipelines and I/O redirection. For example, the shell pipeline gunzip < paper.tex.gz | detex | spell | lpr -Ppulp & would be written in scsh as (& (| (gunzip) (detex) (spell) (lpr -Ppulp)) ; Background a pipeline (< paper.tex.gz)) ; with this redirection Scsh embeds this process notation within a full Scheme implementation. The process notation is realized as a set of macro definitions, and is carefully designed to allow full integration with standard Scheme code. Scsh isn't Scheme-like; it is Scheme. At the scripting level, scsh also has an Awk design, also implemented as a macro that can be embedded inside general Scheme code. Scripts can be written as standalone Scheme source files, with a leading #!/usr/local/bin/scsh -s trigger line. ** Scsh as a systems-programming language ----------------------------------------- Scsh additionally provides the low-level access to the operating system normally associated with C. The current release provides full access to Posix, plus important non-Posix extensions, such as complete sockets support. "Complete Posix" means: fork, exec & wait, sockets, full read, write, open & close, seek & tell, complete file-system access, including stat, chmod/chgrp/chown, symlink, FIFO & directory access, tty & pty support, file locking, pipes, select, file-name pattern-matching, time & date, environment variables, signal handlers, and more. In brief, you can now write Unix systems programs in Scheme instead of C. For example, we have implemented an extensible HTTP server at MIT entirely in scsh. As important as full access to the OS is the manner in which it is provided. Scsh integrates the OS support into Scheme in a manner which respects the general structure of the language. The details of the design are discussed in a joint MIT Lab for Computer Science/University of Hong Kong technical report, "A Scheme Shell," also to appear in a revised format in the "Journal syof Lisp and Symbolic Computation." This paper is also available by ftp: ftp://ftp.scsh.net/pub/scsh/papers/scsh-paper.ps ** Scsh is a portable programming environment --------------------------------------------- Scsh is designed for portability. It is implemented on top of Scheme 48, a byte-code-interpreter Scheme implementation. The Scheme 48 virtual machine can be compiled on any system with a C compiler; the rest of Scheme 48 is machine-independent across 32-bit processors. Scsh's OS interface is also quite portable, providing a consistent interface across different Unix platforms. We currently have scsh implementations for: AIX BSD/OS CXUX FreeBSD HP-UX IRIX Linux NetBSD OpenBSD Solaris SunOS Win32 Darwin/Mac OS X GNU Hurd Scsh code should run without change across these systems. Porting to new platforms is usually not difficult. * Obtaining and installing scsh =============================== You can get a copy of scsh via anonymous ftp, from ftp://ftp.scsh.net/pub/scsh/scsh.tar.gz The tar file includes a detailed manual and a paper describing the design of the system. For the lazily curious, we also have the manual separately available as ftp://ftp.scsh.net/pub/scsh/0.6/scsh-manual.ps Just click 'n view. You *should* be able to build scsh on the standard platforms with exactly five commands: gunzip, tar, cd, ./configure, and make. The configure script figures out the special flags and switches needed to make the build work (thanks to the GNU project for the autoconfig tool that makes this possible). After doing the make, you can start up a Scheme shell and try it out by saying ./go See the manual for full details on the command-line switches. If it's harder than this, and your system is standard, we'd like to know about it. * Getting in touch ================== Currently, there is a mailing-list which is mirrored to a newsgroup. To (un)subscribe to the mailing-list, send a message to scsh-request@@zurich.csail.mit.edu. To submit a message to the mailing-list, send it to scsh@@zurich.csail.mit.edu. The mailing-list is also readable as a standard newsgroup, thanks to gmane, a mail-to-news gateway. More information is available at the following URL: http://gmane.org/info.php?group=gmane.lisp.scheme.scsh There used to be a newsgroup dedicated to scsh, called comp.lang.scheme.scsh but it is now deprecated. Bugs can be reported to scsh-bugs@zurich.csail.mit.edu or via the Scsh project's bugs section on SourceForge: http://sourceforge.net/projects/scsh/ * The World-Wide What? ====================== We even have one of those dot-com cyberweb things: http://www.scsh.net We manage the project using SourceForge: http://sourceforge.net/projects/scsh/ * New in this release ===================== ** Removed or replaced non-free code Some files in the previous versions of scsh did not conform to scsh's BSD-style license. We therefore removed the directory scheme/infix and asked the copyright holders of the rest of the code to put their code under a compatible license. The code of the sort package has been replaced by a new version (see below). ** New code for sorting The old package SORT from Scheme 48 has been replaced by a sophisticated library written by Olin Shivers for the withdrawn SRFI 32. ** Separate documentation of the library directories search facility The manual now contains a separate section that describes the library directories search facility. The description of the respective switches has been adapted accordingly. ** New module CONFIGURE The new module CONFIGURE permits access to some of the values obtained during the run of the configure script. ** Argument processing more robust Any number of whitespaces may now occur between the arguments to the VM. ** Ultrix is no longer supported The Ultrix platform is lacking support for POSIX regular expressions and is therefore no longer supported. ** Bug fixes Fix WITH-LOCk Ensure that the exit value is 1 if scsh exits due to an error Load the package scheme-with-scsh before dumping images to get better start-up times Fix two bugs in GLOB related to quotation The optmizer AUTO-INTEGRATE can now inline procedures with macro-generated arguments The optmizer FLAT-ENVIRONMENTS now works if invoked after AUTO-INTEGRATE Fixed a bug in the parser of "-" sre forms Removed accidentally committed expansion of paths in SCSH_LIB_DIR Fix the various SELECT-like procedures for 0 timeouts Let PATH-LIST->FILE-NAME return "/" for '(""). Fix bug in S48_RECORD_TYPE: third parameter to s48_stob_ref was missing. Fixed check for -rdynamic FIELD-READER returns (values EOF '()) on an empty port Fixed STRING-CONTAINS and STRING-CONCATENATE-REVERSE/SHARED from SRFI-13 * New in 0.6.5 ============== ** New platform: GNU Hurd Andreas Vögele ported scsh to GNU Hurd. ** ./configure option to set default scsh library directories The ./configure script now accepts the option --with-lib-dirs-list to specify a list of default scsh library directories. In previous versions of scsh this list was hardwired to /usr/local/lib/scsh/modules. ** Support for DESTDIR for easier packaging The install target of the Makefile now respects the environment variable DESTDIR to allow package maintainers to use a staging directory. ** New SRFI This release adds support for SRFI 42. ** Switch to load exec scripts from library path The new switch -lel searches the library path for a file and loads the file into the exec package. ** Removed scheme/infix/ The directory scheme/infix/ had a non-free copyright licence and has been removed. ** Bug fixes - SEEK currently works on unbuffered ports only. Check this in the implementation and oopsify it in the manual. - Adjust documentation of some low-level regexp procedures - Removed message argument form errno-error - After fork/pipe, make the ports returned by the pipe the current-in/output-ports - Get the names of MAKE-STRING-PORT-FILTER and MAKE-CHAR-PORT-FILTER right in the doc - Fixed memory leak in scheme_cwd - Fixed memory leak in format_date - Avoid calling SOCKET-OPTION twice in case of an error - Fix for (rx (|)) by Peter Wang - Fix for (posix-string->regexp "$") by Peter Wang ** API changes None known. * New in 0.6.4 ============== ** Switches to load exec scripts The new switch -le loads a file into the exec package, the new switch -de loads the "-s" script into the exec package. ** New SRFIs This release adds support for SRFI 25, 26, 27, 28 and 30. ** Bug fixes - Other select bug - Timeout for select is in seconds, not milliseconds - Load package md5 before dumping scsh.image - Revised implementation of SRFI-19 - -sfd switch called bogus procedures - Ooopsify write-string/partial - Clean up get_groups - Check for "." in file-name-{sans-}extension - Bug fix for let-match: variables may be #f - Fix some problems with WAIT-FOR-CHANNELS - Fixes in the time zone code - Fix a bug in SEND-MESSAGE: There is such a thing as an empty datagram - Renamed string-filter to make-string-port-filter and char-filter to make-char-port-filter ** API changes pause-until-interrupt has been removed because it is not compatible with the thread system * New in 0.6.3 ============== ** Shorter startup times By a couple of small fixes we could diminish the startup time by 10-30%. ** stripped-scsh.image In addition to the standard heap image scsh.image, scsh now ships with an additional image stripped-scsh.image. This image contains the same code as the standard image but has almost all debugging information removed. It is therefore much smaller (2.5 MB vs. 4.5 MB) which also allows shorter startup times. The image is intended for use in scripts but not for interactive development. See the manual for more information. ** MD5 support The package md5 contains a bunch of procedures to compute MD5 checksums. ** New SRFIs This release adds support for SRFI 25, 26, 27, 28 and 30. ** API changes select and select! are supported again. Note however, that we recommend to use the new select-ports and select-port-channels procedures instead whenever possible. New interface to the uname function. New direct interface to the directory stream operations New structure scheme-with-scsh which combines the exports of the modules scsh and scheme, avoiding duplicates New procdures to work directly on file-info records The repl procedure has been removed New procedures connect-socket-no-wait, connect-socket-successful? Add lookup-external from recent S48 ** Bugfixes LET-MATCH, IF-MATCH, and COND-MATCH now behave according to the documentation. Many bug fixes for the SRE system, specifically for dynamic submatches. PORT->SOCKET uses dups both ports of the socket Added missing process resource alignments No reaping for stopped children Initialize t.c_lflag before reading it. Fix to allow single character here strings. Add a whole bunch of S48_GC_PROTECT against s48_extract_integer. Added MAP, FOR-EACH, MEMBER, ASSOC to SRFI 1 interface Fixed a subtle bug in the macro for the << redirection Use "compare" und "rename" to compare symbols in lots of macros Fixed the close method for string-input-ports ... and many others. * New in 0.6.2 ============== ** SRFIs In addition to SRFIs 1, 8, 13, 14 and 23 scsh now features SRFIs 2, 5, 6, 7, 9, 11, 16, 17 and 19. See http://srfi.schemers.org/ for a detailed description. The SRFIs are available in packages srfi-N where N is the number of the SRFI. ** port->socket New procedure port->socket to turn a port into a socket object was added to the network code. ** New forms in the module language The module language supports the new forms modify, subset and with-prefix from Scheme 48 version 0.57. ** API changes Fork, fork/pipe, fork/pipe+ take an optional argument continue-threads? to determine whether all threads should continue to run in the child. exec-path-list is now a preseved thread fluid ** PDF version of the manual There is now a PDF version of the manual generated by pdflatex. ** Bugfixes - Added default argument to tty-info as described in the manual - Conversion to s48_value in tty1.c - Fixed another hygiene problem in SRE - Plugged space leak in bind-listen-accept-loop - Aligned CWD and umask in various file operations - Better releasing of port locks - Corrected exception of time - Set-cloexec to #t for unrevealed ports. - Included scsh paper in the distribution. - Fixed accept for AF_UNIX - (setenv var #f) now deletes var from environment - Quoted { and } within literal strings of regexps * New in 0.6.1 ============== ** API changes For sre's, BOW, EOW, WORD, and WORD+ (which were already unsupported in 0.6.0 on most platforms) are gone for good. ** Bugfixes Most of the known bugs of version 0.6.0 have been fixed, many thanks for the precise reports! See the project page on SourceForge for a list of the remaining known bugs. Here is a brief overview of the fixes: - GC_PROTECT'ed the necessary variables (specifically, where >1 arg to a function 'may GC') (Thanks to Steven Jenkins for dealing with this) - Fixed various race conditons in the signal handling and process reaping code - Fixed bug in set-process-group - If $HOME is unset, consult (user-info (user-uid)) for the value of home-directory - Fix external-call-from-callback problem leading to spurious gc-protection-mismatch exceptions. - Let s48-do-gc return 0 so the PreScheme compiler will emit the correct signature of the function. - scsh/linux/tty-consts.scm: num-ttychars seems to be 32 not 19. - scsh/top.scm: Return 0 exit status for -c and -e. - *.c: Replaced // comments. - scsh/syslog1.c: Remove LOG_LPR from list of syslog levels. - scsh/network1.c: Pass SYSCALL argument to ERRNO-ERROR. - scsh/syscalls1.c: Disable timer interrupts before execve - scsh/network.scm: Correct name extraction in bind-socket - Added export for with-error-output-port - Install HTML version of manual under $(libdir) - ./configure is more rebost wrt $(srcdir) - Fixed installation of the S48 manual - Replaced several /tmp by /var/tmp - Catch EISDIR in delete-filesys-object - flush-all-ports is now non-blocking * New in 0.6.0 ============== ** Scsh is now based on Scheme 48 0.53 With the move from Scheme 48 version 0.36 to version 0.53 in this release the underlying system received a massive update. The most significant changes include: User level threads Advanced garbage collector Improved foreign function interface to C The most significant change for Scsh users is the addition of a user-level thread system. Scsh provides various features to deal with this new power in a system programming environment: An event based interface to interrupts, thread local process state and thread-safe system calls. ** A manual for Scheme 48 has been included Richard Kelsey, the author of Scheme 48, has graciously allowed us to retrofit the current Scheme 48 manual for inclusion in this scsh release. ** Interfaces to dot-locking, crypt and syslog Scsh now provides advisory file locking via the dot-locking scheme and a direct binding to the crypt function. Furthermore we added a complete, system-independent and thread-safe interface to syslog. ** API changes Some features of the previous releases are currently not supported as we did not have the time to implement them. Please tell us, if you can't get along without them. Here is a listing of these currently dereleased features: select select! ODBC support bufpol/line The following procedures received new names in this release: sleep (now process-sleep) sleep-until (now process-sleep-until) network-info, service-info and protocol-info now return #f on non-success. The default directory for creating temporary files has changed: It's now the value of $TMPDIR if set and /var/tmp otherwise. The nth procedure is still there but is now officially obsolete. It will go away in a future release. ** HTML version of the manual There is now a HTML version of the scsh manual generated by tex2page * Thanks ======== We would like to thank the members of local-resistance cells for the Underground everywhere for bug reports, bug fixes, design review and comments that were incorporated into this release. We really appreciate their help, particularly in the task of porting scsh to new platforms. Brought to you by the Scheme Underground. Go forth and write elegant systems programs. -Olin Shivers, Brian Carlstrom, Martin Gasbichler & Mike Sperber