bash Sed 错误：替代命令中的错误标志：'U'
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Sed error: bad flag in substitute command: 'U'
提问by JasmineOT
I'm new in bash script and trying to replace some words in my file using sed. Following is the bash I use in my script:
我是 bash 脚本的新手，并尝试使用 sed 替换文件中的一些单词。以下是我在脚本中使用的 bash：
sed -i '' "s/<pre>.*<\/pre>/<pre>($NEWNAME) $MD5<\/pre>/"~/Desktop/replace.html
And I got error message saying: bad flag in substitute command: 'U'. I use double quote because I need to put variables in.
我收到错误消息说：bad flag in substitute command: 'U'。我使用双引号是因为我需要放入变量。
My environment is Mac.
我的环境是Mac。
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1.Turns out I forgot to leave a space between replace string and file name. Which led to the result always showing: bad flag in substitute command: '~'. It works now.
1.原来我忘记在替换字符串和文件名之间留一个空格。这导致结果总是显示：bad flag in substitute command: '~'。它现在有效。
2.The reason is I used MD5=$(md5 path)to create MD5 value which gets the reault of MD5 (path) *****, and the path contains /which breaks the regex. After changing MD5=$(md5 -q path), it will be ok.
2.原因是我用来MD5=$(md5 path)创建MD5值，它得到reault MD5 (path) *****，并且路径包含/打破正则表达式。改MD5=$(md5 -q path)好后就好了。
回答by anubhava
Most likely your $NEWNAMEvariable has a forward slash in it, which is being used as regex delimiter in sed. Try this sedwith an alternate delimitere.g. ~:
很可能您的$NEWNAME变量中有一个正斜杠，它被用作sed. 尝试sed使用备用分隔符，例如~：
sed -i '' "s~<pre>.*</pre>~<pre>($NEWNAME) $MD5</pre>~" ~/Desktop/replace.html
