这是后续问题，但与我之前发布的另一个问题略有不同：
如何提取两种模式之间的所有内容(使用 sed？
在测试过程中，我还发现在某些情况下，多个记录不仅在单个文件中，而且所有记录都只是在一行中，它们之间没有换行符，当我在那一行组合上运行 sed 命令时，它似乎会找到匹配项， 但是匹配，但这不是第一个匹配(我实际上不知道为什么它与它找到的匹配
(。我知道第一"行"也是最新的记录，所以我想执行 sed 类型匹配以从第一条记录中提取时间，但只能从第一条记录中提取时间。
这里有一个片段来说明我上面试图描述的内容：
UPDATE SUCCESS (key/name): 7c061313-9cbd-4bd1-8613-139cbd2bd1da/snctest38
UPDATE SUCCESS (key/name): 7ebab268-05dc-4110-bab2-6805dc2110f6/snctest4
UPDATE SUCCESS (key/name): 8ef15385-3d23-40e9-b153-853d2310e9fd/snctest5
UPDATE SUCCESS (key/name): 978bf8b5-b4aa-4cd4-8bf8-b5b4aaacd4b6/snctest6
UPDATE SUCCESS (key/name): 34f28da7-1311-4cb7-b28d-a713116cb77d/snctest7
UPDATE SUCCESS (key/name): 7be77991-4c73-4c35-a779-914c73ec359a/snctest8
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如您所见，显然有多条"线"组合成一条大线。
那么，如何修改上一个线程中建议的一些 sed 命令以匹配并提取第一个匹配项呢？
谢谢 吉姆
如果我没看错你的问题(考虑到它对其他问题的依赖，这并不容易(，你只需要两个给定正则表达式(它们本身只是字符串(之间的短路匹配：</messages>和</start>.
sed '/</message>.*</start>/ { s:^.*</message>:</message>:; s:</start>.*$:</start>: }'
这使用 POSIXsed，因为您没有指定您正在使用 GNU(例如通过 Linux 发行版(。首先，我们检查以确保行匹配。如果是这样，请删除最终</message>之前的所有内容，然后在第一个</start>之后删除所有内容。
这对于 GNU(或 BSD(sed会更优雅，因为您可以使用反向引用来保留这些标签：
sed -E '/</message>.*</start>/ { s:^.*(</message>):1:; s:(</start>).*$:1: }'
就个人而言，我会使用 GNU grep(假设它是用 libpcre 编译以支持-P(：
grep -Po '</message>.*?</start>'
这将仅显示这两个给定字符串之间最短匹配的匹配文本。