replace - Can I use sed to manipulate a variable in bash?

Question

In my program, I would like to first get the user input, and insert a before each / so I write this, but it doesn't work.

echo "input a website"
read website

sed '///i/' $website

Answer 1

Try this:

website=$(sed 's|/|\/|g' <<< $website)

Bash actually supports this sort of replacement natively:

${parameter/pattern/string} — replace the first match of pattern with string.
${parameter//pattern/string} — replace all matches of pattern with string.

Therefore you can do:

website=${website////\/}

Explanation:

website=${website // / / \/}
                  ^  ^ ^  ^
                  |  | |  |
                  |  | |  string, '' needs to be backslashed
                  |  | delimiter
                  |  pattern
                  replace globally