旧的 Perl 脚本现在出现错误：名称仅使用一次

Question

我继承了一个旧的 perl 脚本，它从各种形式中获取搜索词并对其进行处理。

我现在在日志中看到脚本抛出以下错误： mastersearch.cgi：名称 "main::error_fields" 仅使用一次：可能在 /var/www/cgi-bin/mastersearch.cgi 第 203 行出现错字。

我在下面指出了错误行，这里是断章取义的：

 ($error,@error_fields) = @_;

我读过只使用一个变量一次，所以看起来这一行，数组错误字段只使用了一次。但是为什么不行呢？

我可以使用 strict 来纠正这个问题吗？我读过其他堆栈问题，但没有看到它们之间的关系，特别是：

"Used only once" warnings can be generated when autodie or Fatal is used with package filehandles (eg, FILE ). Scalar filehandles are strongly recommended instead.

那么我的问题是：

如何消除错误，我不是 perl 人！

和不太重要的：

是时候转储这个脚本了吗？

提前致谢

#!/usr/bin/perl -w
use CGI::Carp qw(fatalsToBrowser);

# @referers allows forms to be located only on servers which are defined 
# in this field.  This prevents other servers from using your SearchWWW script.

@referers = ('http://ourname.edu');

# Check Referring URL
&check_url;

# Parse Form Contents
  &parse_form;

# Submit to search engine
  &search;

sub check_url {
  if ($ENV{'HTTP_REFERER'}) {
    foreach $referer (@referers) {
      if ($ENV{'HTTP_REFERER'} =~ /$referer/i) {
      $check_referer = '1';
      last;
      }
   }
}
else {
  $check_referer = '1';
}

if ($check_referer != 1) {
   &error('bad_referer');
  }
}

sub parse_form {
    if ($ENV{'REQUEST_METHOD'} eq 'GET') {
     # Split the name-value pairs
     @pairs = split(/&/, $ENV{'QUERY_STRING'});
   }
   elsif ($ENV{'REQUEST_METHOD'} eq 'POST') {
     # Get the input
       read(STDIN, $buffer, $ENV{'CONTENT_LENGTH'});
     # Split the name-value pairs
       @pairs = split(/&/, $buffer);
   }
   else {
      &error('request_method');
   }

foreach $pair (@pairs) {
    ($name, $value) = split(/=/, $pair);
    $value =~ tr/+/ /;
    $value =~ s/%([a-fA-F0-9][a-fA-F0-9])/pack("C", hex())/eg;
    $value =~ s/<!--(.|\n)*-->//g;
    $contents{$name} = $value;
   }
}

sub search {
    # Assign the value from search to search_for
   $search_for = $contents{'search'};

    # Places a plus between two words
    $search_for =~ tr/ /+/;

    # If no engine entered goto Google by default
    if ($contents{'location'} eq "15"){
     print "Location: http://ourname.edu/search?q=$search_for";
    }

    if ($contents{'location'} eq "11"){
        print "Location:http://ourname.edu/search~S9/?searchtype=X& searcharg=$search_for&searchscope=39\n\n"
     }
 # ....snipped as redundant for question- more locations here
 #resume

 exit;
}

  sub error {
  # -->the error line, 203,  is below
    ($error,@error_fields) = @_;
    print "Content-type: text/html\n\n";
    if ($error eq 'bad_referer') {
        print qq~ 
        <html>\n <head>\n  <title>Bad Referrer - Access Denied</title></head>\n
    <body>\n  <center>\n   <h1>Bad Referrer - Access Denied</h1></center>\n
    The form that is trying to use this SearchWWW Program</a>\n
    resides at: $ENV{'HTTP_REFERER'}, which is not allowed to access this cgi script.<p>\n
    Sorry!\n
    </body></html>\n ~;
}
 else {
    print qq~
    <html>\n <head>\n  <title>Error: Request Method</title>\n </head>
    </head>\n <body>
    <center>\n\n
    <h1>Error: Request Method</h1>\n  </center>\n\n
    The Request Method of the Form you submitted did not match\n
    either GET or POST.  Please check the form, and make sure the\n
    method= statement is in upper case and matches GET or POST.\n
    </body></html>\n ~;
    }
    exit;
}

Answer 1

首先，这是警告，不是错误。它不会停止脚本的执行，它只是试图提醒您可能有问题，您应该检查一下。

要获取有关警告的更多详细信息，请将 use diagnostics; 添加到脚本的顶部。在这种情况下，您会看到：

Typographical errors often show up as unique variable names. If you had a good reason for having a unique name, then just mention it again somehow to suppress the message...

由于您在初始分配后从未使用 @error_fields，Perl 认为您可能打错了字并警告您。如果您从未对其进行任何操作，则没有理由分配给 @error_fields，因此您只需将其从该行中删除即可：

($error) = @_;

但是该脚本还有很多其他问题（例如没有 use strict;）。我会把它扔掉。

旧的 Perl 脚本现在出现错误：名称仅使用一次

Old Perl Script now with Error-: Name Used only once

perl

cgi