sed中的环境变量替换 [英] Environment variable substitution in sed
问题描述
如果我从脚本运行以下命令:
If I run these commands from a script:
#my.sh
PWD=bla
sed 's/xxx/'$PWD'/'
...
$ ./my.sh
xxx
bla
很好.
但是，如果我运行:
#my.sh
sed 's/xxx/'$PWD'/'
...
$ ./my.sh
$ sed: -e expression #1, char 8: Unknown option to `s'
我在教程中读到，要从shell替换环境变量，您需要停止操作，并在$varname部分中加引号，以使它不被直接替换，这就是我所做的，并且仅当变量有效时才起作用是在紧接之前定义的.
I read in tutorials that to substitute environment variables from shell you need to stop, and 'out quote' the $varname part so that it is not substituted directly, which is what I did, and which works only if the variable is defined immediately before.
我该如何识别$var作为外壳程序中定义的环境变量?
How can I get sed to recognize a $var as an environment variable as it is defined in the shell?
推荐答案
您的两个示例看起来相同，这使问题难以诊断.潜在问题:
Your two examples look identical, which makes problems hard to diagnose. Potential problems:
-
您可能需要双引号，如
sed 's/xxx/'"$PWD"'/'
$PWD可能包含斜杠，在这种情况下，您需要找到$PWD中包含的字符 not 用作定界符.
$PWD may contain a slash, in which case you need to find a character not contained in $PWD to use as a delimiter.
也许要一次解决这两个问题
To nail both issues at once, perhaps
sed 's@xxx@'"$PWD"'@'
这篇关于sed中的环境变量替换的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
