After having my crontab deleted for the 3rd time from "fat fingering" -r instead of -e(they're so close!), I created this little script that adds a prompt to delete the crontab.

1) Create /usr/local/scripts/safe_crontab.pl with the code below.
2) Add this line to /etc/bashrc (or your personal .bashrc) alias crontab='/usr/local/scripts/safe_crontab.pl'
3) Run the following command: chmod 755 /usr/local/scripts/safe_crontab.pl
4) Log off and back on and you should be all set. Hope you find this useful. 
#!/usr/bin/perl -w
use strict;
    
my $run_crontab = 1;
my @safe_argv;
my ( $bForce, $bRemove, $bHelp );
    
foreach ( @ARGV ) {
    if ( uc( $_ ) eq '--FORCE' ) {
        $bForce = 1;
    } else {
        if ( uc( $_ ) eq '-R' ) {
            $bRemove = 1;
        }
        push( @safe_argv, $_ );
    }
}
    
if ( $bRemove ) {
    unless( $bForce ) {
        my ( $y_or_n );
        do {
            print 'Are you sure you want to remove the crontab? (Y/N):
+ ';
            $y_or_n = uc( getc() );
            print \"\n\";
        } until ( ( $y_or_n eq 'Y' ) || ( $y_or_n  eq 'N' ) );
        if ( $y_or_n eq 'N' ) {
            print \"/usr/bin/crontab: no changes made to crontab\n\";
            $run_crontab = 0;
        }
    }
}
    
if ( $run_crontab ) {
    if ( system( '/usr/bin/crontab', @safe_argv ) == 256 ) {
        print \"\t--force (delete crontab without prompting)\n\";
    }
}

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In reply to safe cron by mincus

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