RFC 227 (v1) Extend the window to turn on taint mode

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=head1 TITLE

Extend the window to turn on taint mode

=head1 VERSION

  Maintainer: Adam Turoff <[email protected]>
  Date: Sep 14 2000
  Mailing List: [email protected]
  Number: 227
  Version: 1
  Status: Developing

=head1 ABSTRACT

Taint mode must be turned on when Perl is invoked.  This is frequently
done using:

	perl -T foo.pl

or using a preamble like this:

	#!/usr/bin/perl -T

However, using the #! mechanism to turn on tainting causes
problems with other perl idioms, such as:

	perl -c foo.pl

This dependency should be removed.

=head1 DESCRIPTION

According to the perlrun manpage description of the -T
runtime flag:

    [...] For security reasons, this option must be
    seen by Perl quite early; usually this means it must
    appear early on the command line or in the #! line
    for systems which support that construct.

Perl complains when the -T flag is used with the #! 
mechanism, and perl is explicitly invoked on the 
commandline without the -T flag:

    $ cat foo.pl
    #!/usr/bin/perl -T
    print "Success!\n";

    $ perl foo.pl 
    Too late for "-T" option at foo.pl line 1.

    $ perl -c foo.pl
    Too late for "-T" option at foo.pl line 1.

    $ perl -Tc foo.pl
    foo.pl syntax OK

    $ perl -T foo.pl
    Success!

This RFC proposes that when Perl is explicitly invoked
on the commandline, and runs a script that contains the
-T option on the #! line, Perl should just turn on 
taint mode and not complain about it.

=head1 MIGRATION ISSUES

None.

=head1 IMPLEMENTATION

The call sequence which is used to turn on taint mode
should be modified to handle the scenario described
above.

=head1 REFERENCES

perlsec manpage

perlrun manpage