perl使用$ _读取文件中的每一行不起作用

Question

I am reading 'Beginning Perl: Online book by Simon Cozen'. In my code below, print comment prints all lines of my data.txt file. But my while loop does not print anything. Please help me fix this problem.

open(FILE,'data.txt');
my $line = <FILE>;
my @lines = <FILE>;
print @lines;

while (<FILE>) {
    print "$_";
}

Answer 1

Since you've read the file and now you're "at the end", you need to close the file and open it again to get back to the start.

Alternatively, use seek FILE, 0, SEEK_SET; on the open file to reset back to the start without a close and reopen. (Use use Fcntl qw( SEEK_SET ); to import SEEK_SET .)