regex - Perl Regex 试图读取我评论中的宏

Question

我有一个程序可以将命令嵌入到 XML 文件、属性文件和其他文件的注释中。我识别三种不同类型的评论:

• Perl 和 Shell 脚本注释(以 # 开头的行)
• Python 和 Java 风格的注释(以 // 开头的行)
• XML 样式注释(行以 <-- 开始并以 --> 结束

我有一个 IF 宏，如果一个属性被设置为特定值，我将注释掉以下所有行，直到我得到一个嵌入的 `ENDIF 或不管它们。

这是一个例子:

# IF: MACHINE = SERVER
# SERVER_PORT = 1022
# ENDIF:

这是一个类似的 XML 格式示例:

<!-- IF: NOT MACHINE SERVER -->
    <server>foo.vegicorp.com</server>
<!-- ENDIF: -->

我需要捕获的内容:

   1. 2.  3.   4.    5.    6.   7.
   |  |   |    |     |     |    |
<!-- IF: NOT MACHINE =  SERVER -->

1. 评论的开头(必须在文件的第一列)
2. 字符串 IF:
3. 可选字符串 NOT (如果存在，捕获 #1)
4. 属性名称(捕获 #2)
5. 一个可选等号
6. 属性值(捕获#3)
7. 如果这是 XML 行，则为可选的结束注释

不知何故，我根本没有正确选择正则表达式。这是我拥有的:

$if_line_re = qr@^(?:<\!--|#|//)\s*IF:\s+(?:(NOT)\s+)?(\S+)\s+(?:=\s)?(\S+)(?:\s*-->)?@i;

这是我的模板文件:

# Macro: machine_type choice
# Q: WHat type of machine is this?
# C: Server:SERVER
# C: Client:CLIENT
# C: A type of toaster:TOASTER

# Macro: QUESTION integer
# Q: What is an example of a number

question=%QUESTION%

machine type = %machine_type%

# IF: Machine = SERVER
machine = server

# ENDIF:

# IF: NOT MACHINE = SERVER

Machine = Toaster? Maybe Client?

# ENDIF: 

# IF: Machine = Toaster
machine = Definitely a toaster!

# ENDIF:

模板的填写方式如下:

# Macro: machine_type choice
# Q: WHat type of machine is this?
# C: Server:SERVER
# C: Client:CLIENT
# C: A type of toaster:TOASTER

# Macro: QUESTION integer
# Q: What is an example of a number

question=34

machine type = TOASTER

# IF: Machine = SERVER -->
# machine = server
# 
# ENDIF:

# IF: NOT MACHINE = SERVER

Machine = Toaster? Maybe Client?

# ENDIF: 

# IF: Machine = Toaster
# machine = Definitely a toaster!
# 
# ENDIF:

我添加了一些调试行来显示发生了什么:

DEBUG: if ( 0 and SERVER eq  ) { at ./autoconfig.pl line 1048, <$template_fh> line 32.
DEBUG: if ( not 0 and SERVER ne  ) { at ./autoconfig.pl line 1063, <$template_fh> line 32.
DEBUG: if ( 0 and SERVER eq  ) { at ./autoconfig.pl line 1048, <$template_fh> line 32.
DEBUG: if ( not 0 and SERVER ne  ) { at ./autoconfig.pl line 1063, <$template_fh> line 32.
DEBUG: if ( 1 and SERVER eq  ) { at ./autoconfig.pl line 1048, <$template_fh> line 32.
DEBUG: if ( not 1 and SERVER ne  ) { at ./autoconfig.pl line 1063, <$template_fh> line 32.
DEBUG: if ( 1 and SERVER eq  ) { at ./autoconfig.pl line 1048, <$template_fh> line 32.
DEBUG: if ( not 1 and SERVER ne  ) { at ./autoconfig.pl line 1063, <$template_fh> line 32.
DEBUG: if ( 1 and SERVER eq  ) { at ./autoconfig.pl line 1048, <$template_fh> line 32.
DEBUG: if ( not 1 and SERVER ne  ) { at ./autoconfig.pl line 1063, <$template_fh> line 32.
DEBUG: if ( 0 and Toaster eq  ) { at ./autoconfig.pl line 1048, <$template_fh> line 32.
DEBUG: if ( not 0 and Toaster ne  ) { at ./autoconfig.pl line 1063, <$template_fh> line 32.
DEBUG: if ( 0 and Toaster eq  ) { at ./autoconfig.pl line 1048, <$template_fh> line 32.
DEBUG: if ( not 0 and Toaster ne  ) { at ./autoconfig.pl line 1063, <$template_fh> line 32.

如您所见，我与属性匹配的值未被提取。我的正则表达式匹配该行，但没有捕获属性的值。这是代码:

    elsif ( $line =~ IF_LINE ) {
    my $negation = $1;
    my $parameter = uc $2;
    my $value = $3;
    my $if_clause;
    if ( $negation ) {
        $if_clause = If->new( $parameter, $value, 1 );
    } else {
        $if_clause = If->new( $parameter, $value, 0 );
    }
    push @macro_list, $if_clause;

Answer 1

我将“一个或多个”量词添加到 (?:=\s)，结果是 (?:=\s+):

$if_line_re = qr@^(?:<\!--|#|//)\s*IF:\s+(?:(NOT)\s+)?(\S+)\s+(?:=\s+)?(\S+)(?:\s*-->)?@i;

现在我得到:

MATCH 1
1.  [9-12]  `NOT`
2.  [13-20] `MACHINE`
3.  [23-29] `SERVER`