Question

在下面的字符串中，我要提取子字符串。

场景：

一旦字符串中的wafers_starts匹配，就应从前一个匹配项<ac:structured-macro中选择该字符串。（在下面的示例中有两个，我只需要在wafers_starts之前的一个）
应该选择子字符串，直到它与wafers_ends加上第一个结束标记</ac:structured-macro>匹配为止。

示例代码：

if ($matches -ne $null) { Remove-Variable $matches }

$confluenceHtml = "<h2>Description</h2><ac:structured-macro ac:macro-id=""77f3n751-39w7-4746-acd4-bee7586449ed"" ac:name=""warning"" ac:schema-version=""1""><ac:parameter ac:name=""title"">Compatibility</ac:parameter><ac:rich-text-body><p class=""auto-cursor-target""><br/></p><table class=""wrapped""><colgroup> <col/> <col/> <col/> </colgroup><tbody><tr><th><p>Prerequisite</p><p>This needs a progressive rollout </p></td></tr></tbody></table><p class=""auto-cursor-target""><br/></p><p class=""auto-cursor-target""><br/></p><ac:structured-macro ac:macro-id=""4657sd53-e024-4ea3-a5e2-4586667542da"" ac:name=""excerpt"" ac:schema-version=""1""><ac:parameter ac:name=""hidden"">true</ac:parameter><ac:parameter ac:name=""atlassian-macro-output-type"">INLINE</ac:parameter><ac:rich-text-body><p>wafers_starts</p></ac:rich-text-body></ac:structured-macro><h2>Deployment Notes</h2><ac:structured-macro ac:macro-id=""77f5e121-31d7-4576-awq4-bej57t6d39ed"" ac:name=""warning"" ac:schema-version=""1""><ac:parameter ac:name=""title"">Compatibility</ac:parameter>  <ac:rich-text-body><p class=""auto-cursor-target""><br/></p><table class=""wrapped""><colgroup> <col/> <col/> <col/> </colgroup><tbody><tr><th><p>Prerequisite</p><p>This needs a progressive rollout 2,3,4,5 and so on</p></td></tr></tbody></table><p class=""auto-cursor-target""><br/></p><ac:structured-macro ac:macro-id=""72d7h552-a5dd-44cc-a4re-6f3247574fbd"" ac:name=""excerpt"" ac:schema-version=""1""><ac:parameter ac:name=""hidden"">true</ac:parameter><ac:parameter ac:name=""atlassian-macro-output-type"">INLINE</ac:parameter><ac:rich-text-body><p>wafers_ends</p></ac:rich-text-body></ac:structured-macro><p class=""auto-cursor-target""><br/></p></ac:structured-macro>"

if ($confluenceHtml -match '\<ac:structured-macro.+?wafers_starts([\s\S]*)wafers_ends.+?\<\/ac:structured-macro\>') {  
    $matches[0]
}

输出：

<ac:structured-macro ac:macro-id="77f3n751-39w7-4746-acd4-bee7586449ed" ac:name="warning" ac:schema-version="1"><ac:parameter ac:name="title">Compatibility</ac:parameter><ac:rich-text-body><p class="auto-cursor-target"><br/></p><table class="wrapped"><colgroup> <col/> <col/> <col/> </colgroup><tbody><tr><th><p>Prerequisite</p><p>This needs a progressive rollout </p></td></tr></tbody></table><p class="auto-cursor-target"><br/></p><p class="auto-cursor-target"><br/></p><ac:structured-macro ac:macro-id="4657sd53-e024-4ea3-a5e2-4586667542da" ac:name="excerpt" ac:schema-version="1"><ac:parameter ac:name="hidden">true</ac:parameter><ac:parameter ac:name="atlassian-macro-output-type">INLINE</ac:parameter><ac:rich-text-body><p>wafers_starts</p></ac:rich-text-body></ac:structured-macro><h2>Deployment Notes</h2><ac:structured-macro ac:macro-id="77f5e121-31d7-4576-awq4-bej57t6d39ed" ac:name="warning" ac:schema-version="1"><ac:parameter ac:name="title">Compatibility</ac:parameter>  <ac:rich-text-body><p class="auto-cursor-target"><br/></p><table class="wrapped"><colgroup> <col/> <col/> <col/> </colgroup><tbody><tr><th><p>Prerequisite</p><p>This needs a progressive rollout 2,3,4,5 and so on</p></td></tr></tbody></table><p class="auto-cursor-target"><br/></p><ac:structured-macro ac:macro-id="72d7h552-a5dd-44cc-a4re-6f3247574fbd" ac:name="excerpt" ac:schema-version="1"><ac:parameter ac:name="hidden">true</ac:parameter><ac:parameter ac:name="atlassian-macro-output-type">INLINE</ac:parameter><ac:rich-text-body><p>wafers_ends</p></ac:rich-text-body></ac:structured-macro>

问题：

子字符串的结尾可以。但是，即使经过几次尝试也无法获得子字符串的开头。正则表达式从<ac:structured-macro的第一次出现开始就包括在内。

期望的输出：

我只想要下面的子字符串，该子字符串只包含一次<ac:structured-macro，就在第一个匹配的字符串wafers_starts之前

<ac:structured-macro ac:macro-id="4657sd53-e024-4ea3-a5e2-4586667542da" ac:name="excerpt" ac:schema-version="1"><ac:parameter ac:name="hidden">true</ac:parameter><ac:parameter ac:name="atlassian-macro-output-type">INLINE</ac:parameter><ac:rich-text-body><p>wafers_starts</p></ac:rich-text-body></ac:structured-macro><h2>Deployment Notes</h2><ac:structured-macro ac:macro-id="77f5e121-31d7-4576-awq4-bej57t6d39ed" ac:name="warning" ac:schema-version="1"><ac:parameter ac:name="title">Compatibility</ac:parameter>  <ac:rich-text-body><p class="auto-cursor-target"><br/></p><table class="wrapped"><colgroup> <col/> <col/> <col/> </colgroup><tbody><tr><th><p>Prerequisite</p><p>This needs a progressive rollout 2,3,4,5 and so on</p></td></tr></tbody></table><p class="auto-cursor-target"><br/></p><ac:structured-macro ac:macro-id="72d7h552-a5dd-44cc-a4re-6f3247574fbd" ac:name="excerpt" ac:schema-version="1"><ac:parameter ac:name="hidden">true</ac:parameter><ac:parameter ac:name="atlassian-macro-output-type">INLINE</ac:parameter><ac:rich-text-body><p>wafers_ends</p></ac:rich-text-body></ac:structured-macro>

问题：

寻找正确的/有效的正则表达式模式。

Answer 1

您需要使用此正则表达式，该正则表达式使用tempered greedy token (?:(?!ac:structured-macro).)+模式来拒绝ac:structured-macro的首次匹配之后的任何进一步匹配。

<ac:structured-macro(?:(?!ac:structured-macro).)+wafers_starts([\s\S]*)wafers_ends.+?<\/ac:structured-macro>

Demo

如何使用正则表达式匹配子字符串并在匹配之前和之后获取一些额外的字符串

1 个答案: