Question

让我的Perl CGI脚本呈现HTML时遇到很多麻烦。它始终将HTML输出为纯文本。我什至尝试使用print header("text/html");

显式设置 Content-Type

以下代码有什么问题吗？ -

use CGI qw(:standard);

# other code

print header("text/html"); 
# also tried just print header;

my $banner = "Some text";
print start_html($banner);
print h3($banner);

print start_form(-method=>"POST");
# HTML form specific code
print end_form;

print end_html;

当我在Chrome开发人员工具上检查 Elements 标签时，出于某种原因，整个HTML都包裹在<pre>标签内，而标签又在另一个HTML文档中。因此HTML格式不正确，但我无法理解为什么-

    <html>

    <head></head>

    <body>
        <pre style="word-wrap: break-word; white-space: pre-wrap;">&lt;!DOCTYPE html
        PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
         "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"&gt;
    &lt;html xmlns="http://www.w3.org/1999/xhtml" lang="en-US" xml:lang="en-US"&gt;
    &lt;head&gt;
    &lt;title&gt;Some text&lt;/title&gt;
    &lt;meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1" /&gt;
    &lt;/head&gt;
    &lt;body&gt;
    &lt;h3&gt;Some text&lt;/h3&gt;&lt;form method="post" action="/path/script.pl?param1=val1&param2=val2" enctype="multipart/form-data"&gt;

    //form specific code

&lt;/form&gt;
    &lt;/body&gt;
    &lt;/html&gt;</pre>
    </body>

    </html>

任何帮助将不胜感激。

Answer 1

运行程序时，得到以下输出：

Content-Type: text/html; charset=ISO-8859-1

<!DOCTYPE html
    PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
     "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" lang="en-US" xml:lang="en-US">
<head>
<title>Some text</title>
<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1" />
</head>
<body>
<h3>Some text</h3><form method="post" action="http://localhost" enctype="multipart/form-data"></form>
</body>
</html>

这正是我所希望看到的，与您所看到的完全不同。我可以看到两种可能性来解释这种差异：

程序的# other code部分中有一些东西正在输出一组CGI标头（也许还有<pre>标签）。
您实际上并没有在CGI环境中运行代码，并且存在一些不寻常的Web配置，该配置从程序中获取输出并将其嵌入到另一个Web页面中。

区分这两种情况的一种简单方法是从命令行运行程序，然后查看获得的输出。如果您得到输出，则问题出在# other code中，如果您得到我的输出，则问题出在Web服务器配置中。

顺便说一句，我强烈建议您阅读HTML Generation functions should no longer be used和CGI module documentation页面的最新版本中标题为CGI::Alternatives的部分，以获取一些更好方法的建议。

Answer 2

以下代码有什么问题吗？ -

是的。对于初学者来说，它甚至不编译。

$ perl <<'__EOS__'
use CGI qw(:standard);

// other code

print header("text/html"); // also tried just print header;
my $banner = "Some text";
print start_html($banner);
print h3($banner);

print start_form(-method=>"POST");
// HTML form specific code
print end_form;

print end_html;
__EOS__
Bareword found where operator expected at - line 3, near "// other"
        (Missing operator before other?)
Bareword found where operator expected at - line 3, near "other code"
        (Do you need to predeclare other?)
Bareword found where operator expected at - line 5, near "// also"
        (Missing operator before also?)
Bareword found where operator expected at - line 11, near "// HTML"
        (Missing operator before HTML?)
Bareword found where operator expected at - line 11, near "specific code"
        (Do you need to predeclare specific?)
syntax error at - line 3, near "// other "
syntax error at - line 5, near "// also tried "
syntax error at - line 11, near "// HTML form "
Execution of - aborted due to compilation errors.

但是在将所有//更改为#之后，我们得到了一个很好的程序，它不会输出任何PRE元素。

$ perl <<'__EOS__'
use CGI qw(:standard);

# other code

print header("text/html"); # also tried just print header;
my $banner = "Some text";
print start_html($banner);
print h3($banner);

print start_form(-method=>"POST");
# HTML form specific code
print end_form;

print end_html;
__EOS__
Content-Type: text/html; charset=ISO-8859-1

<!DOCTYPE html
        PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
         "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" lang="en-US" xml:lang="en-US">
<head>
<title>Some text</title>
<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1" />
</head>
<body>
<h3>Some text</h3><form method="post" action="http://localhost" enctype="multipart/form-data"></form>
</body>
</html>

Answer 3

尝试一下：

print(header(-type => 'text/html'));

至少对我有用。

即使在显式配置Content-Type之后，Perl CGI脚本也会输出原始HTML

3 个答案: