-*- Outline -*-

* Scsh binary for Cygwin

The binary was compiled on an older Cygwin installation:

   CYGWIN_NT-5.1 xxx 1.3.5(0.47/3/2) 2001-11-13 23:16 i686 unknown

You will need cygwin1.dll in a directory in your path.

Please note that I'm providing this binary "AS IS". USE IT AT YOUR OWN
RISK!  I don't have the time to support it.

To use it just unpack the archive under /usr/local (the path is hard
coded in the Scsh binary) and enjoy.  A complete installation is
included.

* Compiling Scsh under Cygwin

To compile Scsh under Cygwin you have to make sure that the directory
where Scsh is being compiled as well as the directory where temporary
files are created during the compilation are mounted in "binary" mode.
Otherwise you will get errors about corrupted images.

For example:

   mount -b c:/home/ecl/scheme/scsh/scsh-0.6.7 /scsh
   mount -b c:/tmp /tmp

Now change the working directory to /scsh and start the compilation
there with

   ./configure
   make

The build should finish without any problems and everything else
seems to work but at least with the old Cygwin I'm using one gets a
misleading "heap overflow" error when using regexps:

   /scsh% ./go
   Welcome to scsh 0.6.7 (R6RS)
   Type ,? for help.
   > (+ 3 39)
   42
   > (car '(a b c))
   'a
   > (file-exists? "./scshvm.exe")
   #t
   > (regexp-search? (rx printing) "foo")
   Scheme48 heap overflow
   [Last command exited with status 255]

The reason for this is that the scshvm.exe binary fails to find the regexp
library.

At this point I edited the (automatically generated) Makefile and added 
Cygwin's "/lib/libregex.a" to LIBS:

   diff -c "/scsh/Makefile.~1~" "/scsh/Makefile"
   *** /scsh/Makefile.~1~	Tue Oct 31 09:35:51 2006
   --- /scsh/Makefile	Tue Oct 31 09:51:32 2006
   ***************
   *** 8,14 ****

     CC = gcc
     DEFS = -DHAVE_CONFIG_H
   ! LIBS = -lcrypt -lm  -lutil
     CFLAGS = -O2
     INSTALL = /usr/bin/install -c
     INSTALL_PROGRAM = ${INSTALL}
   --- 8,14 ----

     CC = gcc
     DEFS = -DHAVE_CONFIG_H
   ! LIBS = /lib/libregex.a -lcrypt -lm  -lutil
     CFLAGS = -O2
     INSTALL = /usr/bin/install -c
     INSTALL_PROGRAM = ${INSTALL}

   Diff finished.  Tue Oct 31 09:51:39 2006

Now using regular expressions should work, but you get an error
when using e.g. the "printing" char class, as reported by Matthew
R. Dempsky [1]:

   /scsh% ./go
   Welcome to scsh 0.6.7 (R6RS)
   Type ,? for help.
   > (regexp-search? (rx (= 2 "o")) "foo")
   #t
   > (regexp-search? (rx printing) "foo")

   Error: Posix regexp ([^²³¹¼½¾--]) : invalid character range
          #{Regexp}
   1> 

Michael Sperber explained [2] this is due to a regexp library which
doesn't allow characters above the ASCII range.  Also there has been
complaints that the regexp library shipped with Cygwin is not POSIX
compliant.

One solution is to install the GNU regexp library from
ftp://ftp.gnu.org/gnu/regex/regex-0.12.tar.gz.  After unpacking, run
the "configure" script as usual:

   % ./configure

and then

   % make regex.o

Now use "ar" to build a library containing regex.o:

   % ar ru libgnuregex.a regex.o

Now copy GNU's "regex.h" to the include directory, usually /usr/include,
and move "libgnuregex.a" to the Cygwin library directory, usually /lib.

Modify the Makefile to link against "/lib/libgnuregex.a".  After a
"make clean" followed by "make" everything should now work:

   /scsh% ./go
   Welcome to scsh 0.6.7 (R6RS)
   Type ,? for help.
   > (regexp-search? (rx (= 2 "o")) "foo")
   #t
   > (regexp-search? (rx printing) "foo")
   #t
   > 

You can umount the directories after the compilation.

No changes to Scsh's source code are necessary at all.

 Emilio Lopes <eclig@gmx.net>


Footnotes:

[1] http://article.gmane.org/gmane.lisp.scheme.scsh/7615

[2] http://article.gmane.org/gmane.lisp.scheme.scsh/7616