sub i{$_=<>;chop;if(/^\d{1,4}$/){return sprintf("%04d",$_)}print"!\n";
+&i}$c=i;$d=i;for($c..$d){$_="bar$_.jpg";print"$_\n"unless(-e)}

[download]

Enter first then last in sequence. no check made that second number is larger than first (not in challenge :))

! means re-enter digit

131 chars (includes 'bonus' challenge).

Hmmm, that was fun :)

cLive ;-)

Update: if larger strings *are* valid as long as they are numerically correct, the above needs amending to: 

sub i{$_=<>;chop;if(/^\d+$/&&$_<10000){return sprintf("%04d",$_)}print
+"!\n";&i}$c=i;$d=i;for($c..$d){$_="bar$_.jpg";print"$_\n"unless(-e)}

[download]

adding another 6 chars...

In reply to Re: Perl Golf Proposal by cLive ;-)
in thread Perl Golf Proposal by sharle

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