Today, I was facing (once more) with the following need: I need to update a setting in a text file but if the variable is not yet present, I need to add it.
So, in short, I need to make a search and replace or insert new line.
Using sed it's quite easy to automate the search & replace but how to append?
jq is a powerful utility for Linux allowing manipulating JSON data from the command line and can be integrated into shell scripts.
Using jq you can beautify JSON output but also filter it like f.i. showing only a given node.
xmlstarlet is a powerful utility for Linux allowing manipulating XML data from the command line and can be integrated into shell scripts.
Using xmlstarlet you can beautify XML output but also filter it like f.i. showing only a given node.