That's better.
A few comments:
- Always check the result of a file open or I/O operation.
- You don't need to know the size of your file to use sysread. You
can say how much sysread should read, and that function will return the
number of bytes read, or 0 when it's finished.
- If you really need to know the file size, use a -s check.
Here is an example.
#!/usr/bin/perl
use warnings;
use strict;
my $filename = "stable.tar.gz"; # it's the latest Perl source code
die "filename not found\n" unless -f $filename;
my $size = -s $filename;
my $total_read = 0;
open F, "< $filename"
or die "can't open $filename\n";
my $bufsize = 2_000_000;
my $buffer;
while ( my $read = sysread(F , $buffer , $bufsize, ) )
{
printf "Read %8u bytes\n", $read;
# do something with $buffer
$total_read += $read;
}
print "initial size: $size\n";
print "total read: $total_read\n";
__END__
output:
Read 2000000 bytes
Read 2000000 bytes
Read 2000000 bytes
Read 2000000 bytes
Read 2000000 bytes
Read 2000000 bytes
Read 254916 bytes
initial size: 12254916
total read: 12254916
HTH
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