Perl：为什么 "seek" 不起作用

Question

我正在尝试浏览一堆文本文件两次以查找两个不同的值。但是，seek $fh, 0, 0 似乎不起作用。为什么？

请帮忙

我的代码：

 use strict;
 use warnings;
 ...
 read_in_data_employer();
 read_in_data_union();
 process_files ($FileFolder);
 close $FileHandle;
 ...
 sub process_files
 {
         opendir (DIR, $FileFolder)
                 or die "Unable to open $FileFolder: $!";
         my @files = grep { /.pdf.txt/ } readdir (DIR);
         closedir (DIR);
         @files = map { $FileFolder . '/' . $_ } @files;
         foreach my $file (@files)
         {
                 open (my $txtfile, $file) or die "error opening $file\n";
                 print "$file";
                 LookForEmployer:
                 {
                         print $FileHandle "\t";
                         while (my $line=<$txtfile>)
                         {
                                 foreach (@InputData_Employers)
                                 {
                                         if ($line =~ /\Q$_/i)
                                         {
                                                 print $FileHandle "$_";
                                                 last LookForEmployer;
                                         }
                                 }
                         }
                 }
                 seek ($txtfile, 0, 0);
                 LookForUnion:
                 {
                         print $FileHandle "\t";
                         while (my $line=<$txtfile>)
                         {
                                 print "$.\n";
                                 foreach (@InputData_Unions)
                                 {
                                         if ($line =~ /\Q$_/i)
                                         {
                                                 print $FileHandle "$_";
                                                 last LookForUnion;
                                         }
                                 }
                         }
                 }
                 close $txtfile
         }
 }

输出：

>perl "test.pl" test "employers.txt" "unions.txt" output.txt
test/611-2643-03 (801-0741).pdf.txt12
13
14
15
16
17
18
19
20
21
22
test/611-2643-05 (801-0741).pdf.txt
7
8
9
10
11
12
test/611-2732-21 (805-0083).pdf.txt
2
3
4
5
6
7
8
test/611-2799-17 (801-0152).pdf.txt
6
7
8
9
10
11
12
13
14

谢谢

Answer 1

文件没有行号。他们甚至没有台词。文件只有字节。这意味着您不能只询问系统 "What line of the file is at this position?"

但是，由于您正在查找文件的开头，因此您只需重置 $.。

use Fcntl qw( SEEK_SET );

seek($txtfile, 0, SEEK_SET)
   or die("seek: $!\n");

$. = 0;

顺便说一下，你的程序效率低得离谱。将数据加载到哈希或数据库中！

Perl：为什么 "seek" 不起作用

Perl: How come "seek" is not working

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