I want to replace a unique string in a markdown file with another unique string located in a separate text file.
I would like to do this with basic Linux commands that I can run with GitHub actions.
To generate the unique string that I want to replace, I:
grep -Po '(?<=href=")[^"]*(?=")' filename | head -1 > replace.txt
Next I want to search a file, locate the string found in replace.txt, and overwrite it with a string found within inject.txt (inject only contains the unique string).