#!/usr/bin/perl
#

use strict;
use warnings;

# Get modules, set autoflush on STDOUT.
#
use IO::File;
use Term::ReadKey;
STDOUT->autoflush(1);

# Get name of script we want to create, die if it already
# exists.
#
my $newfile = shift or
   die "Usage: newscript <filename>\n";
die "newscript: $newfile already exists\n" if
   -e $newfile or -l $newfile;

# Make new IO::File handle to create script file with execute
# permissions, die on failure.
#
my $scriptFH = IO::File->new($newfile,
   O_WRONLY|O_CREAT|O_TRUNC, 0755);
die "newscript: open: $!\n" unless $scriptFH;

# Set up hash-bang line and strictures for top of script, write
# them to the new file and then close.
#
my $hashBang =
   "#!/usr/bin/perl\n#\n\nuse strict;\nuse warnings;\n\n";
$scriptFH->print($hashBang);
$scriptFH->close();

# Set up editor command, prompts asking user if they want to
# edit the new script, and a time-out value of five seconds.
#
my $editor = "/usr/local/bin/nedit";
our $prompt1 = "Start editing $newfile? (";
our $prompt2 = ") (y/n) : ";
our $timeOut = 5;

# Set up subroutine reference that will be used as the handler
# for $SIG{ALRM}.
#
our $rcCountdown = sub
{
    # If there is still time left, print prompt (decrementing
    # time-out value) and set alarm for one second.
    #
    if($timeOut)
    {
        print "\r", $prompt1, $timeOut --, $prompt2;
        alarm(1);
    }

    # Time is up, restore read mode and die.
    #
    else
    {
        ReadMode(0);
        die "Timed out\n"
    }
};

# Install handler, call handler for the first time to prompt
# and set alarm.
#
$SIG{ALRM} = $rcCountdown;
$rcCountdown->();

# Set read mode to raw and await a key press.
#
ReadMode(4);
my $resp = ReadKey(0);

# If we got here we got a key press, reset read mode, unset
# alarm and print a newline to move off prompt.
#
ReadMode(0);
alarm(0);
print "\n";

# If key pressed was 'y' then start the editor in the
# background via exec, new editor window will appear and
# shell will prompt for next command.
#
if($resp =~ /^y$/i)
{
    exec "$editor $newfile &" or
       die "Couldn't invoke $editor: $!\n";
}

# User doesn't want to edit so just exit.
#
exit;