How do I find out what version of a bower package is actually installed?

问题

Normally a bower.json file specifies some dependencies, but these are typically expressed so that they allow a range of versions of a bower package to be used (e.g. >=1.0, which means anything higher than version 1.0).

I have an automated process which needs to find what version of a bower package is actually installed on this system right now.

How can I find this out programmatically (just the version itself), ideally using standard Unix command line tools / the bower command?

bower info <thepackagename> does not show this - it shows information about what is currently available from the bower repository (for example, even if I do bower info apackageIdonthaveinstalled it will still show a valid JSON structure containing a version number).

cat bower_components/thepackagename/bower.json | node_modules/json/lib/json.js version works for some packages (assuming the npm package json is installed), but not all (e.g. jquery 2.2.0's bower package does not contain a bower.json).

回答1:

Here's a grep command to do that: grep "version\"\:" bower_components/thepackagename/.bower.json

Also, a command to see versions of all bower components for the project - this list can be a handy CI artefact: grep "version\"\:" bower_components/*/.bower.json

回答2:

Have you ever tried "bower list --json=0 --offline".

It would list all bower packages info.

回答3:

The best approach I've now found, which seems to work for every package I've come across so far, is:

cat bower_components/thepackagename/.bower.json | node_modules/json/lib/json.js version

(note the extra . in .bower.json).

It would appear that bower stores some metadata about the installed package in .bower.json, and that includes the installed version.

The best I've come up with so far is:

bower list | grep jquery | perl -pe 's/.*jquery#(.*?) .*$/$1/'

(if, for example, the package I was interested in was jquery).

That's pretty ugly for a variety of reasons:

• I have to repeat the package name (although this could probably be improved with a better Perl script which filters lines too, I'm just being lazy).

• bower list gets information about all installed packages, not just the one I'm interested in - the rest of the information is discarded.

• bower list seems to require internet connectivity to check the registry, otherwise it fails.

Would be interested to see if this could be improved upon, particularly the last point.

来源：https://stackoverflow.com/questions/35368144/how-do-i-find-out-what-version-of-a-bower-package-is-actually-installed