NOTE: There are a few housekeeping things that this obviously doesn't do, e.g. checking for a valid code label, etc. I left them out intending to do that when it comes time for real implementation.

The main script, recover.pl

#!/usr/local/bin/perl
use Getopt::Std;
our ($opt_r);
getopts('r:');

my $recover             = uc $opt_r;
$recover and goto ($recover);

my $rec_file_name       = 'start.rec';

FIRST:          first();
SECOND:         second();
THIRD:          third();
CleanUp();


# do the first task
sub first
{
        # some other stuff may happen here, 
        #  so we'll go ahead and write the recovery info
        write_recovery_file('first');
        print STDERR "This is first\n";
        sleep(1);
#       die "died in first";
}

sub second
{
        write_recovery_file('second');
        print STDERR "This is second\n";
        sleep(1);
#       die "died in second";
}

sub third
{
        write_recovery_file('third');
        print STDERR "This is third\n";
        sleep(1);
#       die "died in third";
}


sub CleanUp
{
        `rm start.rec`;
        print "Recovery file deleted\n" unless ($?);
}

sub write_recovery_file
{
        my $str = shift;
        open RECOVER, ">$rec_file_name";
        print RECOVER "$0 -r$str\n";
        close RECOVER;
}
[download]

#!/usr/local/bin/perl
# This tests the recovery system

$recovery_file = check_for_recovery_file();

# execute the script at either the recovery step or the beginning
$recovery_file ? recover($recovery_file) : recover();

sub recover
{
        my $file_name = shift;
        my $cmd_line = 'recover.pl';
        if ($file_name)
        {
                open INFILE, "$file_name";
                # assumes the recovery file contains 
                #  no more than one line of text
                chomp($cmd_line = <INFILE>);    
                print STDERR "Resuming failed process: '$cmd_line'";
        }
        `$cmd_line`;
        die "Could not execute $file_name: $!" if ($?);
        print STDERR "'$cmd_line' successful\n";
}

sub check_for_recovery_file
{
        # won't hard-code this in real life
        $_ = 'start.rec';
        (-s) ? return $_ : return 0
}
[download]

Any thoughts?

MM