Mini Shell

If you read this file _as_is_, just ignore the funny characters you
see. It is written in the POD format (see perlpod manpage) which is
specially designed to be readable as is.

=head1 NAME

perlamiga - Perl under AmigaOS 4.1

=head1 NOTE

This is a port of Perl 5.22.1, it is a fresh port and not in any way
compatible with my previous ports of Perl 5.8 and 5.16.3. This means
you will need to reinstall / rebuild any third party modules you have
installed.

newlib.library version 53.28 or greater is required.

=head1 SYNOPSIS

Once perl is installed you can read this document in the following way

	sh -c "perldoc perlamiga"

or you may read I<as is>: either as F<README.amiga>, or F<pod/perlamiga.pod>.

=cut

       NAME
       SYNOPSIS
       DESCRIPTION
         -  Prerequisites
         -  Starting Perl programs under AmigaOS
         -  Shortcomings of Perl under AmigaOS
       INSTALLATION
       CHANGES

=head1 DESCRIPTION

=head2 Prerequisites for running Perl 5.22.1 under AmigaOS 4.1

=over 6

=item B<AmigaOS 4.1 update 6 with all updates applied as of 9th October 2013>

The most important of which is:

=item B<newlib.library version 53.28 or greater>

=item B<AmigaOS SDK>

Perl installs into the SDK directory structure and expects many of the
build tools present in the SDK to be available. So for the best results
install the SDK first.

=item B<abc-shell>

If you do not have the SDK installed you must at least have abc-shell
installed or some other suitable sh port. This is required to run
external commands and should be available as 'sh' in your path.

=back

=head2 Starting Perl programs under AmigaOS 4.1

Perl may be run from the AmigaOS shell but for best results should be
run under abc-shell.  (abc-shell handles file globbing, pattern
expansion, and sets up environment variables in the UN*Xy way that
Perl expects.)

For example:

	New Shell process 10
	10.AmigaOS4:> sh
	/AmigaOS4>perl path:to/myprog arg1 arrg2 arg3

Abc-shell can also launch programs via the #! syntax at the start of
the program file, it's best use the form #!SDK:Local/C/perl so that
the AmigaOS shell may also find perl in the same way. AmigaOS requires
the script bit to be set for this to work

	10.AmigaOS4:> sh
	/AmigaOS4>myprog arg1 arrg2 arg3

=head2 Limitations of Perl under AmigaOS 4.1

=over 6

=item B<Nested Piped programs can crash when run from older abc-shells>

abc-shell version 53.2 has a bug that can cause crashes in the
subprocesses used to run piped programs, if a later version is
available you should install it instead.

=item B<Incorrect or unexpected command line unescaping>

newlib.library 53.30 and earlier incorrectly unescape slashed escape
sequences e.g. \" \n \t etc requiring unusual extra escaping.

=item B<Starting subprocesses via open has limitations>

	open FH, "command |"

Subprocesses started with open use a minimal popen() routine and
therefore they do not return pids usable with waitpid etc.

=item If you find any other limitations or bugs then let me know.

Please report bugs in this version of perl to andy@broad.ology.org.uk
in the first instance.

=back

=head1 INSTALLATION

This guide assumes you have obtained a prebuilt archive from os4depot.net.

Unpack the main archive to a temporary location (RAM: is fine).

Execute the provided install script from shell or via its icon.

You B<must not> attempt to install by hand.

Once installed you may delete the temporary archive.

This approach will preserve links in the installation without creating
duplicate binaries.

If you have the earlier ports perl 5.16 or 5.8 installed you may like
to rename your perl executable to perl516 or perl58 or something
similar before the installation of 5.22.1, this will allow you to use
both versions at the same time.

=head1 Amiga Specific Modules

=head2 Amiga::ARexx

The Amiga::ARexx module allows you to easily create a perl based ARexx
host or to send ARexx commands to other programs.

Try C<perldoc Amiga::ARexx> for more info.

=head2 Amiga::Exec

The Amiga::Exec module introduces support for Wait().

Try C<perldoc Amiga::Exec> for more info.

=head1 BUILDING

To build perl under AmigaOS from the patched sources you will need to
have a recent version of the SDK. Version 53.29 is recommended,
earlier versions will probably work too.

With the help of Jarkko Hietaniemi the Configure system has been tweaked to
run under abc-shell so the recommend build process is as follows.

	stack 2000000
	sh Configure -de
	gmake

This will build the default setup that installs under SDK:local/newlib/lib/

=head1 CHANGES

=over 6

=item B<August 2015>

=over 2

=item Port to Perl 5.22

=item Add handling of NIL: to afstat()

=item Fix inheritance of environment variables by subprocesses.

=item Fix exec, and exit in "forked" subprocesses.

=item Fix issue with newlib's unlink, which could cause infinite loops.

=item Add flock() emulation using IDOS->LockRecord thanks to Tony Cook
for the suggestion.

=item Fix issue where kill was using the wrong kind of process ID

=back

=item B<27th November 2013>

=over 2

=item Create new installation system based on installperl links
and Amiga protection bits now set correctly.

=item Pod now defaults to text.

=item File::Spec should now recognise an Amiga style absolute path as well
as an Unix style one. Relative paths must always be Unix style.

=back

=item B<20th November 2013>

=over 2

=item Configured to use SDK:Local/C/perl to start standard scripts

=item Added Amiga::Exec module with support for Wait() and AmigaOS signal numbers.

=back

=item B<10th October 13>

First release of port to 5.16.3.

=back

=head1 SEE ALSO

You like this port?  See L<http://www.broad.ology.org.uk/amiga/>
for how you can help.

=cut