Shell：使用sed替换文件中的字符串

Question

I am writing a script to replace a string in a file in linux.

this is my code:

echo "Enter file name? "
read FILE1
echo "You have entered, $FILE1"

echo "String to be replaced "
read STR1
echo "You have entered, $STR1"

echo "Replace by "
read STR2
echo "You have entered, $STR2"

sed -i 's/$STR1/$STR2/g' /misc/home3/abc/$FILE1

echo "DONE !!"

The string is not getting replace in the file. what could be wrong with it??

Thanks :)

Answer 1

Do not use ' for the sed-string but " like this:

sed -i "s/$STR1/$STR2/g" /misc/home3/abc/$FILE1

Double quotes allow the shell to do variable expansion inside of the quoted text. Single tick ' prevents this.