在bash中如何替换字符串变量，并将其设置为sed命令

Question

in a bash script file, I have set one variable like this:

    current_path=`pwd`
    sed -i "1s/.*/working_path='$current_path';/" file1.sh

I want to run this script to replace the first line of file1.sh into working_path='$current_path'; , but the current_path has the / and in the sed command, the / is predefined in sed replace pattern. And I have tried this:

    current_path1="${current_path/\//\\\/}"

the above line, I want to replace the / in variable current_path into \\/ , then input the current_path1 into the sed command, but also has an error.

Could you give me some advice, please? Thanks.

Answer 1

Try this.

sed -i -e "1s@.*@working_path='$current_path';@" file1.sh

Use @ instead of / in the substitute command.

Answer 2

You can use different delimiters for the s/// command:

current_path=`pwd`
sed -i "1s|.*|working_path='$current_path';|" file1.sh

But you're not really searching and replacing here,, you want to insert the new line and delete the old line:

current_path=`pwd`
sed -i -e "1i\working_path='$current_path)';" -e 1d file1.sh

Are you really changing the first line of a .sh file? Are you deleting the she-bang line?

Answer 3

Please add a '/' to the beginning of pattern string. It replaces all matches of pattern with string.

 current_path1="${current_path//\//\\\/}"