【Perl】模块 Tie::File

1 Tie::File

建立一个list和file的关系，对list的操作会反映到file上去。

 

use Tie::File;
tie @array, 'Tie::File', filename or die ...;


$array[13] = 'blah';     # line 13 of the file is now 'blah'
print $array[42];        # display line 42 of the file

$n_recs = @array;        # how many records are in the file?
$#array -= 2;            # chop two records off the end


for (@array) {
  s/PERL/Perl/g;         # Replace PERL with Perl everywhere in the file
}

# These are just like regular push, pop, unshift, shift, and splice
# Except that they modify the file in the way you would expect

push @array, new recs...;
my $r1 = pop @array;
unshift @array, new recs...;
my $r2 = shift @array;
@old_recs = splice @array, 3, 7, new recs...;

untie @array;            # all finished

2 应用举例

 

use Tie::File;
my @array;
my $filename = "a.txt";
tie(@array,'Tie::File',$filename) or die;
print "$array[3]\n";
print "$#array\n";
$array[3] = "hello";
$array[1] = "world";
splice(@array, 1, 0, "insert into 0 and 1 line");
delete $array[$#array];
$#array -= 2;
print pop @array;
untie($array);

3 more help

perldoc Tie::File