This directory, and its subdirectories contain the source code
for ksh-93; the language described in the second addition of
the book, "The KornShell Command and Programming Language," by
Morris Bolsky and David Korn which is published by Prentice Hall.
ksh-93 has been compiled and run on several machines with several
operating systems.  The end of this file contains a partial list of
operating systems and machines that ksh-93 has been known to run on.

The layout of files for ksh-93 has changed somewhat since ksh-88,
the last major release.  Most of the source code for ksh remains in
the sh directory.  However, the shell editing and history routines
are in the edit sub-directory.  The code for shell built-ins is
in the bltins directory.  The data directory contains read-only
data tables and messages that are used by the shell.  The include
files remain in the include directory and the shlib directory
is gone.  The features directory replaces the older install
directory. The method for generating systems specific feature
information has changed substantially.

The Makefile file contains several compilation options that can be set
before compiling ksh.  Options are of the form SHOPT_option and become
#define inside the code.  These options are set to their recommended
value and some of these may disappear as options in future releases.
A value of 0, or no value  represents off, 1 represents on.
Note that == is needed, not =, because these are nmake state variables
and changing their value will cause all modules that could be affected
by this change to be recompiled.
The options have the following defaults and meanings:
    ACCT         off Shell accounting.
    ACCTFILE     off Enable per user accounting info
    APPEND       on  Allows var+=val string and array append.
    BASH         off Bash compatibility mode.  It is not fully implemented
                     and is experimental.
    BRACEPAT     on  C-shell type abc{d,e}f style file generation
    CMDLIB_BLTIN off Makes all commands in libcmd.a builtins.  The
                     SH_CMDLIB_DIR nmake state variable can be used to
		     specify a directory. 
    CMDLIB_DIR   off Sets CMDLIB_BLTIN=1 and provides a default value
                     of "/opt/ast/bin" for SH_CMDLIB_DIR.
    COMPOUND_ARRAY
                 on  Allows all components of compound variables except the
                     first to be any string by enclosing in [...].  It also
                     allows components other than the last to be arrays.
                     This is experimental and only partially complete.
    CRNL         off <cr><nl> treated as <nl> in shell grammar.
    DYNAMIC      on  Dynamic loading of builtins. (Requires dlopen() interface.)
    ECHOPRINT    off Make echo equivalent to print.
    ESH          on  Compile with emacs command line editing.  The original
                     emacs line editor code was provided by Mike Veach at IH.
    FILESCAN     on  Experimental option that allows fast reading of files
                     using while < file;do ...; done and allowing fields in
                     each line to be accessed as positional parameters.
    FS_3D        off For use with 3-D file system.  Enabled automatically for
                     sytems with dynamic linking.
    KIA          off Allow generation of shell cross reference database with -I.
    MULTIBYTE    on  Multibyte character handling.  Requires mblen() and
                     mbctowc().
    NAMESPACE    on  Allows namespaces.  This is experimental, incomplete
                     and undocumented.
    OLDTERMIO    off Use either termios or termio at runtime.
    OO           on  Experimental object oriented extension.  This option
                     should disappear soon.
    OPTIMIZE     on  Optimize loop invariants for with for and while loops.
    P_SUID       off If set, all real uids, greater than or equal to this
                     value will require the -p flag to run suid/sgid scripts.
    PFSH         off Compile with support for profile shell.
    RAWONLY      off Turn on if the vi line mode doesn't work right unless
                     you do a set -o viraw.
    SEVENBIT     off Strip the eigth bit from characters.
    SPAWN        off Use spawn as combined fork/exec.  May improve speed on
                     some systems.
    SUID_EXEC    on  Execute /etc/suid_exec for setuid, setgid script.
    TIMEOUT      off Set this to the number of seconds for timing out and
                     exiting the shell when you don't enter a command.  If
                     non-zero, TMOUT can not be set larger than this value.
    VSH          on  Compile with vi command line editing.  The original vi
                     line editor code was provided by Pat Sullivan at CB.

The following compile options are set automatically by the feature testing:
    DEVFD   Set when /dev/fd is a directory that names open files.
    SHELLMAGIC
            Set on systems that recognize script beginning with #! specially.
    VPIX    Set on systems the have /usr/bin/vpix program for running MS-DOS.


In most instances, you will generate ksh from a higher level directory
which also generates libcmd and libast libraries on which ksh depends.
However, it is possible to generate ksh, with by running make -f ksh.mk
in this directory.  The ksh.mk file was generated from the nmake Makefile.
If you do not have make or nmake, but do have a Version 7 UNIX compatible
shell, then you can run the script mamexec < Mamfile to build ksh.
If you have nmake, version 2.3 or later, you can use it without the -f ksh.mk.
In either case, ksh relies on libraries libast and libcmd which must be
built first.  The binary for ksh becomes the file named ./ksh which can
be copied to where ever you install it.

If you use old make or the Mamfile, and you system has dynamic shared
libraries, then you should define the variables mam_cc_static and
mam_cc_dynanamic as the compiler options that request static linking
and dynamic linking respectively.  This will decrease the number of
shared libraries that ksh need and cut startup time substantially.

The makefile should also generate shcomp, a program that will precompile
a script.  ksh93 is able to recognize files in this format and process
them as scripts.  You can use shcomp to send out scripts when you
don't want to give away the original script source.

It is advisable that you put the line PWD=$HOME;export PWD into the
/etc/profile file to reduce initialization time for ksh.

To be able to run setuid/setgid shell scripts, or scripts without read
permission, the SUID_EXEC compile option must be on, and ksh must be installed
in the /bin directory, the /usr/bin directory, the /usr/lbin directory,
or the /usr/local/bin directory and the name must end in sh. The program
suid_exec must be installed in the /etc directory, must be owned by root,
and must be a suid program.  If you must install ksh in some other directory
and want to be able to run setuid/setgid and execute only scripts, then
you will have to change the source code file sh/suid_exec.c explicitly.
If you do not have ksh in one of these secure locations, /bin/sh will
be invoked with the -p options and will fail when you execute a setuid/setgid
and/or execute only script.  Note, that ksh does not read the .profile
or $ENV file when it the real and effective user/group id's are not
equal.

The tests sub-directory contains a number of regression tests for ksh.
To run all these tests with the shell you just built, go to the tests
directory and run the command
        SHELL=../ksh shtests

The file PROMO.mm is an advertisement that extolls the virtues of ksh.
The file sh.1 contains the troff (man) description of this Shell.
The file nval.3 contains the troff (man) description of the name-value
pair library that is needed for writing built-ins that need to
access shell variables.

The file sh.memo contains a draft troff (mm) memo describing ksh.  The
file RELEASE88 contains the changes made for ksh88.  The file RELEASE93
contains the changes made in this release since ksh-88.  The file
RELEASE contains bug fixes made in this release since ksh-88.  The file
COMPATIBILITY contains a list of incompatibilities with ksh-88.  The
file bltins.mm is a draft troff (mm) memo describing how to write
built-in commands that can be loaded at run time.

Most of the work for internationalization has been done with ksh93.
The file ksh.msg is a generated file that contains error messages
that need to be translated.  In addition, the function translate()
in sh/init.c has to be completed to interface with the dictionary
lookup.  The translate function takes two argument, the string
that is to be translated and a type which is
    0 when a library string needs translation.
    1 when one of the error messages in ksh.msg needs translation.
    2 when a string in a script needs translation.  You use a $ in front
      of a double quoted string in a script to indicate that it
      needs translation.  The -D option for ksh builds the dictionary.
The translate routine needs to return the translated message.
For dictionaries that need to use a numeric key, it should be
possible to use the strhash() function to generate numbers to
go along with each of the messages and to use this number both
when generating the dictionary and when converting strings.
If you encounter error messages of type 1 that are not be translated via
this translate() function send mail to the address below.

Please report any problems or suggestions to:

dgk@research.att.com


ksh93 has been compiled and alpha tested on the following.  An asterisk
signifies that ksh has been installed as /bin/sh on this machine.

*    Sun OS 4.1.[123] on sparc.
     Sun OS 4.1.1 on sun.
     Solaris 2.[1-9] on sparc.
     Solaris 2.[4-8] on X86.
     HP/UX 8 on HP-9000/730.
     HP/UX 9 on HP-9000/730.
     HP/UX 10 on HP-9000/857.
     HP/UX 11 on pa-risc.
     System V Release 3 on Counterpoint C19
     System V Release  4 on AT&T Intel 486.
     System V Release  4 on NCR 4850 Intel 486.
     IRIX Release 4.0.? System V on SGI-MIPS.
     IRIX Release 5.1 System V on SGI-MIPS.
     IRIX Release 6.[1-5] System V on SGI-MIPS.
     System V Release 3.2 on 3B2. 
     UTS 5.2.6 on Amdahl 3090,5990,580.
     System V Release 3.2 on i386.
     SMP_DC.OSx olivetti dcosx MIServer-S 2/128.
     SMP_DC.OSx Pyramid dcosx MIServer-S 2/160 r3000.
     4.3BSD on Vax 8650.
     AIX release 2 on RS6000.
     AIX 3.2 on RS6000.
     Linux 1.X on Intel
     Linux 2.X on Intel
     Linux 2.X on Alpha
     Linux 2.X on Alpha
     Linux 2.X on OS/390
     Linux 2.X on sparc
     Linux 2.4 on intel itanium 64
     Linux Slackware on sparc64
*    Linux ARM on i-PAQ 
     OSF1 on DEC alpha.
     OSF4 on DEC alpha.
     UMIPS 4.52 on mips.
     BSD-i [2-4] on X86.
     OpenBSD on X86
     NetBSD on X86
     FreeBSD on X86
     NeXT on Intel X86.
     NeXT on HP.
*    Windows NT using UWIN on X86
*    Windows NT using UWIN on alpha
     Windows NT using Cygwin on X86
     Windows NT with NutCracker libraries.
     Windows NT with Portage libraries.
     Windows 3.1 using custom C library.
     OpenEdition on MVS
     Darwin OS X on PPC
     MVS on OS 390
     SCO Openserver 3.2 on X86
     Unixware 7 on X86

Good luck!!

David Korn
dgk@research.att.com