I liked your approach. I'm not sure you need the sub in it
though; you're already doing variable interpolation when you
open( OUT, ">$outfile" ) or die ... so you could lean it up a bit:
open( OUT, ">${_}_distilled" ) or die ...

Here's what your code inspired me to do

#!/usr/bin/perl

for(glob '*')
{
  /^$0$/ and next;  # don't process the script
  open(I,"<$_") or die("$_: $!");
  open(O,">$_.$$") or die("$_: $!");

  print O $_,"\n";
  { $. > 4 ? last : print O while(<I>); }

  close(I);
}

exit;
[download]

While writing and subsequently edting above program I discov-
ered the redundancy of local() in certain contexts. I originally wrote
{ local $_ = undef; $. > 4 ? last : print O while(<I>) }
RRedundancy bad, so local went away.

Update: changed >$outfile_distilled
to ${_}_distilled which actually makes sense
in the context of the original program.

blyman

If you like brief you might like this:

#!/usr/bin/perl -w

while(<*>) {
    next if /^$0$/;
    open I, $_        or die "$_: $!";
    open O,">$_.bak"  or die "$_.bak: $!";
    print O $_, "\n", (<I>)[0..3];
    close I, close O;
}
[download]

cheers

tachyon

s&&rsenoyhcatreve&&&s&n.+t&"$'$`$\"$\&"&ee&&y&srve&&d&&print

Shorter still -

open(LOG, ">logfile.txt");
while($FL = <*.extension>) {
    open(FL) and print LOG "$_\n",(<FL>)[0..3] and close(FL)
}
close(LOG);
[download]

But we could golf this 'til the cows come home :o)
HTH

broquaint

I like it really brief. The only reason I have close(I)
is to reset $. You don't ever use $. so $. doesn't need to
be reset - therefore the close calls aren't needed. This
works just as well for me...


#!/usr/bin/perl -w

while(<*>) {
    next if /^$0$/;
    open I, $_        or die "$_: $!";
    open O,">$_.bak"  or die "$_.bak: $!";
    print O $_, "\n", (<I>)[0..3];
    #close I, close O;
}
[download]

A few things I picked up from your code:
You used .bak instead of .$$, which makes your solution
portable beyond *nix systems. I like your <*> more than my
glob. Your treatment of the filehandle as though it were an
array is also new to me.

blyman