错误脚本 额外的环境变量包括CGI 1.1 变量传递给错误脚本。这些CGI 1.1 变量有：

REDIRECT_REQUEST ：这是当正确发送给服务器的请求。

REDIRECT_URL ：这是导致错误的请求URL。

REDIRECT_STATUS ：这是如果NCSA HTTPd 已经允许应答的状态数字和信息。

另外，NCSA HTTPd在err_string=error_message时作为NCSA HTTPd产生的QUERY_STRING错误字符串传递。一些错误信息可以需要一些不在CGI规范中的文件头。基于这个原因，以下给出一个没有解析的文件头的脚本，它是用Perl编写的：

#!/usr/local/bin/perl

# 这是一个利用Perl编写的没有解析文件头的CGI 1.1错误脚本来处理错误请求。

$error = $ENV{'QUERY_STRING'};

$redirect_request = $ENV{'REDIRECT_REQUEST'};

($redirect_method,$request_url,$redirect_protocal) = split(' ',$redirect_request);

$redirect_status = $ENV{'REDIRECT_STATUS'};

if (!defined($redirect_status)) {

$redirect_status = "200 Ok";

}

($redirect_number,$redirect_message) = split(' ',$redirect_status);

$error =~ s/error=//;

$title = "";

if ($redirect_method eq "HEAD") {

$head_only = 1;

} else {

$head_only = 0;

}

printf("%s %s\r\n",$ENV{'SERVER_PROTOCOL'},$redirect_status);

printf("Server: %s\r\n",$ENV{'SERVER_SOFTWARE'});

printf("Content-type: text/html\r\n");

$redirect_status = "".$redirect_status;

if ($redirect_number == 302) {

if ($error !~ /http:/) {

printf("xLocation: http://%s:%s%s\r\n",

$ENV{'SERVER_NAME'},

$ENV{'SERVER_PORT'},

$error);

if (!$head_only) {

printf("%s\r\n",$title);

printf("

%s

\r\n",$redirect_status);

printf("This document has moved");

printf("here.\r\n",

$ENV{'SERVER_NAME'},

$ENV{'SERVER_PORT'},

$error);

}

} else {

printf("Location: %s\r\n",$error);

if (!$head_only) {

printf("%s\r\n",$title);

printf("

%s

\r\n",$redirect_status);

printf("This document has moved");

printf("here.\r\n",$error);

}

}

} elsif ($redirect_number == 400) {

printf("\r\n");

if (!$head_only) {

printf("%s\r\n",$title);

printf("

%s

\r\n",$redirect_status);

printf("Your client sent a request that this server didn't");

printf(" understand.
Reason: %s\r\n",$error);

}

} elsif ($redirect_number == 401) {

printf("WWW-Authenticate: %s\r\n",$error);

printf("\r\n");

if (!$head_only) {

printf("%s\r\n",$title);

printf("

%s

\r\n",$redirect_status);

printf("Browser not authentication-capable or ");

printf("authentication failed.\r\n");

}

} elsif ($redirect_number == 403) {

printf("\r\n");

if (!$head_only) {

printf("%s\r\n",$title);

printf("

%s

\r\n",$redirect_status);

printf("Your client does not have permission to get");

printf("URL:%s from this server.\r\n",$ENV{'REDIRECT_URL'});

}

} elsif ($redirect_number == 404) {

printf("\r\n");

if (!$head_only) {

printf("%s\r\n",$title);

printf("

%s

\r\n",$redirect_status);

printf("The requested URL:%s ",

$ENV{'REDIRECT_URL'});

printf("was not found on this server.\r\n");

}

} elsif ($redirect_number == 500) {

printf("\r\n");

if (!$head_only) {

printf("%s\r\n",$title);

printf("

%s

\r\n",$redirect_status);

printf("The server encountered an internal error or ");

printf("misconfiguration and was unable to complete your ");

printf("request \"%s\"\r\n",$redirect_request);

}

} elsif ($redirect_number == 501) {

printf("\r\n");

if (!$head_only) {

printf("%s\r\n",$title);

printf("

%s

\r\n",$redirect_status);

printf("The server is unable to perform the method ");

printf("%s at this time.",$redirect_method);

}

} else {

printf("\r\n");

if (!$head_only) {

printf("%s\r\n",$title);

printf("

%s

\r\n",$redirect_status);

}

}

if (!$head_only) {

printf("

The following might be useful in determining the problem:");

printf("

\r\n");

open(ENV,"env|");
while () {
printf("$_");
}
close(ENV);
printf("

\r\n

---

");

printf(" Back to Root of Server\r\n",

$ENV{'SERVER_NAME'},$ENV{'SERVER_PORT'});

printf("

---

webmaster\@%s / ",

$ENV{'SERVER_NAME'},$ENV{'SERVER_NAME'});

printf("httpd\@ncsa.uiuc.edu");

printf("\r\n");