=pod

Code submission from: Philip L. Robare (probare@shrike.depaul.edu)

A Perl interactive shell program.  This little bit of code allows you
to test out one-liners and regular expressions to quickly see if they
do what you think they do.  Upon entry a prompt ("perl> ") is 
presented and you may type any perl expression.  When Enter is pressed
the expression is handed over to "eval" and the results come back to
you.  Any error messages are echoed.  Assignments become part of the
execution environment so that you may assign on one line and test the
variable's value on another.  Any line starting with a question mark
is transformed into a print statement.  A previous line may be 
re-entered with the prompt still attached and it will be stripped off.
This allows triple clicking to copy the line and re-execute it.
Exit the script by typing "exit". This will be passed to eval which
will then exit.

Example:
perl> $a="This is a test"
 
perl> if ($a =~ /test/) { print "Test found"; } else { print "Test not found"}
Test found
perl> $a="This is practice"
 
perl> perl> if ($a =~ /test/) { print "Test found"; } else { print "Test not found"}
Test not found
perl> ?$a
This is practice
perl> exit




=cut

# Phil Robare, Chicago IL, USA
$prompt="perl> ";
print "Perl Interpretive Shell - type exit to leave\n\n";
print $prompt;
while(<>) {
    s/^$prompt//;   # previous line is cut & pasted - ignore prompt
    s/^\?/print /;  # a question mark as the first char becomes "print"
    eval;
    warn $@ if $@;  # print out any error messages
    print "\n$prompt";
}