Copying or Moving a File
Problem
You need to copy a file, but Perl has no built-in copy command.
Solution
Use the copy
function from the standard File::Copy
module:
use File::Copy; copy($oldfile, $newfile);
You can do it by hand:
open(IN, "< $oldfile") or die "can't open $oldfile: $!"; open(OUT, "> $newfile") or die "can't open $newfile: $!"; $blksize = (stat IN)[11] || 16384; # preferred block size? while ($len = sysread IN, $buf, $blksize) { if (!defined $len) { next if $! =~ /^Interrupted/; # ^Z and fg die "System read error: $!\n"; } $offset = 0; while ($len) { # Handle partial writes. defined($written = syswrite OUT, $buf, $len, $offset) or die "System write error: $!\n"; $len -= $written; $offset += $written; }; } close(IN); close(OUT);
Or you can call your system’s copy program:
system("cp $oldfile $newfile"); # unix system("copy $oldfile $newfile"); # dos, vms
Discussion
The File::Copy module provides copy
and
move
functions. These are more convenient than
resorting to low-level I/O calls and more portable than calling
system
. move
works across
file-system boundaries; the standard Perl built-in
rename
(usually) does not.
use File::Copy; copy("datafile.dat", "datafile.bak") or die "copy failed: $!"; move("datafile.dat", "datafile.new") or die "move failed: $!";
Because these functions return only a simple success status, you can’t easily tell which file prevented the copy or move from being done. Copying the files manually lets you pinpoint which files didn’t copy, but it fills your ...
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