如果用户没有 select 单选按钮 Perl/CGI，我该如何发送错误消息

Question

尝试编写我的第一个 Perl/CGI 脚本并将运行用于某些领域，我不太了解如何继续前进。创建了一个 HTML 页面，其中包含用户输入并发送到脚本的信息。如果用户不遵循指示，该脚本会在第二页上将信息输出回错误给用户。我的表单如下所示：

项目编号：用户输入一个数字
产品名称：
产品成本：
售价：

产品类别： - 单选按钮 1 - 单选按钮 2 - 单选按钮 3

手头数量（输入字段）
提交按钮

如果用户没有 select 单选按钮，我如何测试并发送错误我想要 return 应该由脚本在第二页上自动生成的利润金额（价格 - 成本）。到目前为止，这是我的脚本（我使用记事本++作为编辑器）

#!/usr/bin/perl

print "Content-type: text/html\n\n";

use CGI qw(:standard);

local ( $buffer, @pairs, $pair, $name, $value, %FORM );

# Read in text
$ENV{'REQUEST_METHOD'} =~ tr/a-z/A-Z/;
if ( $ENV{'REQUEST_METHOD'} eq "POST" ) {
    read( STDIN, $buffer, $ENV{'CONTENT_LENGTH'} );
}
else {
    $buffer = $ENV{'QUERY_STRING'};
}

# Split information into name/value pairs
@pairs = split( /&/, $buffer );
foreach $pair ( @pairs ) {
    ( $name, $value ) = split( /=/, $pair );
    $value =~ tr/+/ /;
    $value =~ s/%(..)/pack("C", hex())/eg;
    $FORM{$name} = $value;
}

#variables for input text fields
$Item     = $FORM{Item};
$Name     = $FORM{Name};
$Cost     = $FORM{Cost};
$Price    = $FORM{Price};
$Quantity = $FORM{Quantity};

#Radio button
$letter = $FORM{letter};

#Validate data is entered in first 2 input boxes
if ( $Item eq "" ) {
    print "$Item Field Cannot be Blank";
}

if ( $Name eq "" ) {
    print "$Name Field cannot be Blank";
}

#Validate the correct amount is entered
if ( $Cost >= .50 && $Cost <= 1000 ) {
    print "$Cost Cost must be between $.50 and 00";
}

if ( $Price >= 1.00 && $Cost <= 2000 ) {
    print "$Price Price must be between .00 and 00";
}

#Validate Category is Chosen

#Validate Quantity on hand not less than 0
if ( $Quantity < 0 ) {
    print "$Quantity Quantity on-hand cannot be less than 0";
}

Answer 1

单选按钮通常用于预定义选项。所以只需将它设置为默认选项，这样最终用户就必须将其更改为其他选项，否则使用默认值

Answer 2

假设您想坚持使用 CGI 作为一项技术（坦率地说，这在 2015 年是荒谬的）那么您的代码可以简化为这样的东西。

#!/usr/bin/perl

use strict;
use warnings;
use CGI qw(:standard);

my @errors;

#Validate data is entered in first 2 input boxes
foreach my $param (qw[Item Name]) {
  if ( ! defined param($param) ) {
    push @errors, "$param Field Cannot be Blank";
  }
}

#Validate the correct amount is entered
my $cost = param('Cost');
if ( $cost >= .50 && $cost <= 1000 ) {
  push @errors, 'Cost must be between $.50 and 00';
}

my $price = param('Price')
if ( $price >= 1.00 && $price <= 2000 ) {
  push @errors, 'Price must be between .00 and 00';
}

#Validate Quantity on hand not less than 0
if ( param('Quantity') < 0 ) {
    push @errors, 'Quantity on-hand cannot be less than 0';
}

print header;

# You now need to send an HTML response to the user. If you have errors
# in @errors, then you need to send them a page which describes what they
# have got wrong. If @errors is empty, then you should send them a page
# containing whatever information they need next.

if (@errors) {
  # create and send an error page
} else {
  # create and send the next page
}

如果用户没有 select 单选按钮 Perl/CGI，我该如何发送错误消息

How can I send error message if user doesn't select a radio button Perl/CGI

html

perl

cgi