如何正确地将值100的参数`q`传递给我的sed表达式? [英] How can I pass correctly the parameter `q` with value 100 to my sed expression?

问题描述

我正在尝试了解关于sed的返回码(不匹配)的答案，但是表达式 sed'/foo/{s/f/b/; q}毫无意义./foo/！{q100}'.他不能创造一个简单的例子吗?为什么会有这么多的斜杠/，分号; 和额外的一对/foo/.

I am trying to understand the answer on Return code of sed for no match, but it dos not make any sense the expression sed '/foo/{s/f/b/;q}; /foo/!{q100}'. He could just not create a simple example? Why these so many slashes /, semicolons ; and extra pair of /foo/.

我试图用 foo 替换 tr ，并在成功执行操作时使sed的返回码 $?$ 为100.我尝试了此代码，但无法正常工作.

I am trying to replace the tr by foo and make sed have the return code $? of 100 when its succeeds the operation. I tried this code and does not work.

echo "trash"|sed 's/tr/foo/!{q100}'; echo $?

输出为:

sed: -e expression #1, char 10: unknown option to `s'
1

如何正确将值100的参数 q 传递给sed表达式?

How can I pass correctly the parameter q with value 100 to my sed expression?

推荐答案

您的sed命令错误；这样就可以了:

Your sed command is wrong; this does the job:

$ echo trash | sed '/tr/{ s/tr/foo/; q100 }'
fooash
$ echo $?
100

sed命令的作用:

/tr/ {      # find the tr string, then enter the block
s/tr/foo/;  # replace tr with foo
q100        # exit with 100
}

不幸的是，众所周知， sed 是一种加密语言.所有的斜杠和分号都必须先用眼球解密.我强烈建议您在深入学习之前，先阅读一个完整的sed教程: http://www.grymoire.com/Unix/sed.html

Unfortunately, sed is well known to be an encrypted language. All the slashes and semicolons need to be decrypted first with eyeballs. I highly recommend you to follow a good and thorough sed tutorial before stepping into the deep water: http://www.grymoire.com/Unix/sed.html

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