Edit package.json from command line

Question

I'm trying to add or edit a variable in my package.json from a shell script. So if i have a package.json like this:

{   "name": "my-project",   "description": "Project by @DerZyklop",   "version": "0.0.0",   ... 

I want a command like

npm config set foo bar 

that adds a new field like

{   "name": "my-project",   "description": "Project by @DerZyklop",   "foo": "bar",   "version": "0.0.0",   ... 

...but unfortunately npm config set just edits the ~/.npmrc and not my package.json.

Answer 1

The package.json is just a json file, so you could use the tool json. To install it use:

npm install -g json 

Then you can edit a file in-place. More information here.

Example

$ cat package.json {   "name": "my-project",   "description": "Project by @DerZyklop",   "version": "0.0.0" }  $ json -I -f package.json -e "this.foo=\"bar\"" json: updated "package.json" in-place  $ cat package.json {   "name": "my-project",   "description": "Project by @DerZyklop",   "version": "0.0.0",   "foo": "bar" } 

Answer 2

If you don't want to install sponge or json, you can also do

echo "`jq '.foo="bar"' package.json`" > package.json