Beefy Boxes and Bandwidth Generously Provided by pair Networks
good chemistry is complicated,
and a little bit messy -LW

Re: easy file copy

by Parham (Friar)
on Mar 29, 2002 at 23:00 UTC ( #155350=note: print w/replies, xml ) Need Help??

in reply to easy file copy

open(IN, "< $input"); open(OUT, "> $output"); print OUT "--- begin stuff ---\n"; print OUT <IN>; # <- this is the cool part print OUT "---- end stuff ----\n"; close(IN); close(OUT);
there would be a few things which would cause this process to go a bit wrong. First, I'd use flock just in case two people decided to copy the file at the same time (chances of this are next to nothing, but why take the chance). Second, i'd binmode because you might be on a OS which distinguishes from binary and text. Finally, instead of printing all at once, i'd print in chunks just to save memory. This is what i'd do:
my $flock = 1 open (FILE1, "file_to_copy.ext") or die "Can't open for reading: $!"; open (FILE2, ">file_to_create.ext") or die "Can't open for writing: $! +"; binmode FILE1; if ($flock == 1) { flock (FILE2, 2); } binmode FILE2; while ( read(FILE1,$file_contents,1024) ) { print FILE2 $file_contents; } close (FILE1); if ($flock == 1) { flock (FILE2, 8); } #this is in fact not needed, th +anx to crazyinsomniac for pointing out the insignificance ... read "f +ile locking" for more information close (FILE2);

Log In?

What's my password?
Create A New User
Node Status?
node history
Node Type: note [id://155350]
[marto]: 1nickt, no snow, just some ice on the roads and the usual idiocy associated with humans and driving in less than ideal conditions
[1nickt]: Corion I am trying to keep an open mind :-) Or at least, go with the flow. marto yes I saw som photos of lorries overturned on country roads, and wondered why they would have been driving fast enough to have that happen!

How do I use this? | Other CB clients
Other Users?
Others romping around the Monastery: (8)
As of 2017-12-11 11:54 GMT
Find Nodes?
    Voting Booth?
    What programming language do you hate the most?

    Results (289 votes). Check out past polls.