在 for 循环中使用带有变量的 sed 的 Bash 脚本？
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Bash script using sed with variables in a for loop?
提问by LF4
I'm trying to write a bash script that takes a few variables and then does a find/replace with a given file search using grep to get the list of files that have the string. I think the issue I'm having is having the variables be seen in sed I'm not sure what else it might be.
我正在尝试编写一个 bash 脚本，它接受一些变量，然后使用 grep 使用给定的文件搜索进行查找/替换，以获取具有该字符串的文件列表。我认为我遇到的问题是在 sed 中看到变量我不确定它可能是什么。
if [ "$searchFiles" != "" -a "$oldString" != "" -a "$newString" != "" ]; then
echo -en "Searching for '$searchFiles' and replacing '$oldString' with '$newString'.\n"
for i in `grep $oldString $searchFiles |cut -d: -f1|uniq`; do
sed -i 's/${oldString}/${newString}/g' $i;
done
echo -en "Done.\n"
else
usage
fi
回答by Karoly Horvath
use double quotes so the shell can substitute variables.
使用双引号，以便 shell 可以替换变量。
for i in `grep -l $oldString $searchFiles`; do
sed -i "s/${oldString}/${newString}/g" $i;
done
if your search or replace string contains special characters you need to escape them: Escape a string for a sed replace pattern
如果您的搜索或替换字符串包含特殊字符，您需要对它们进行转义：Escape a string for a sed replace pattern
回答by Conspicuous Compiler
Use double quotes so the environmental variables are expanded by the shell before it calls sed:
使用双引号，以便 shell 在调用 sed 之前扩展环境变量：
sed -i "s/${oldString}/${newString}/g" $i;
Be wary: If either oldStringor newStringcontain slashes or other regexp special characters, they will be interpreted as their special meaning, not as literal strings.
小心：如果oldString或newString包含斜杠或其他正则表达式特殊字符，它们将被解释为它们的特殊含义，而不是文字字符串。
