如何使用npm安装软件包？

Question

I have never used nodejs before. I just found out about the npm. If you wanted to install a package using npm, will you have to download the file first? If so, where do you put the file? would you place it in the same folder as the npm?

I tried to install faye with npm and this is what I got on the npm-debug.log:

0 info it worked if it ends with ok
1 verbose cli [ 'C:\\Program Files\\nodejs\\\\node.exe',
1 verbose cli   'C:\\Program Files\\nodejs\\node_modules\\npm\\bin\\npm-cli.js',
1 verbose cli   'install',
1 verbose cli   'faye' ]
2 info using npm@2.7.4
3 info using node@v0.12.2
4 verbose node symlink C:\Program Files\nodejs\\node.exe
5 silly cache add args [ 'faye', null ]
6 verbose cache add spec faye
7 silly cache add parsed spec { raw: 'faye',
7 silly cache add   scope: null,
7 silly cache add   name: 'faye',
7 silly cache add   rawSpec: '',
7 silly cache add   spec: '*',
7 silly cache add   type: 'range' }
8 verbose addNamed faye@*
9 silly addNamed semver.valid null
10 silly addNamed semver.validRange *
11 silly addNameRange { name: 'faye', range: '*', hasData: false }
12 silly mapToRegistry name faye
13 silly mapToRegistry using default registry
14 silly mapToRegistry registry https://registry.npmjs.org/
15 silly mapToRegistry uri https://registry.npmjs.org/faye
16 verbose addNameRange registry:https://registry.npmjs.org/faye not in flight; fetching
17 verbose request uri https://registry.npmjs.org/faye
18 verbose request no auth needed
19 info attempt registry request try #1 at 7:19:45 PM
20 verbose request id e2cc452cb2788a4b
21 http request GET https://registry.npmjs.org/faye
22 info retry will retry, error on last attempt: Error: connect EACCES
23 info attempt registry request try #2 at 7:19:55 PM
24 http request GET https://registry.npmjs.org/faye
25 info retry will retry, error on last attempt: Error: connect EACCES
26 info attempt registry request try #3 at 7:20:55 PM
27 http request GET https://registry.npmjs.org/faye
28 verbose stack Error: connect EACCES
28 verbose stack     at exports._errnoException (util.js:746:11)
28 verbose stack     at TCPConnectWrap.afterConnect [as oncomplete] (net.js:1000:19)
29 verbose cwd C:\tito3
30 error Windows_NT 6.1.7601
31 error argv "C:\\Program Files\\nodejs\\\\node.exe" "C:\\Program Files\\nodejs\\node_modules\\npm\\bin\\npm-cli.js" "install" "faye"
32 error node v0.12.2
33 error npm  v2.7.4
34 error code EACCES
35 error errno EACCES
36 error syscall connect
37 error Error: connect EACCES
37 error     at exports._errnoException (util.js:746:11)
37 error     at TCPConnectWrap.afterConnect [as oncomplete] (net.js:1000:19)
37 error  { [Error: connect EACCES] code: 'EACCES', errno: 'EACCES', syscall: 'connect' }
38 error Please try running this command again as root/Administrator.
39 verbose exit [ 1, true ]

Answer 1

Npm will download the relevant files for the module for you.

There are 2 modes of installing node modules using npm, either locally or globally. Locally (the default) means the modules are downloaded to a node_modules directory at the location you ran the command, so you would normally run this at the root of your app project. Globally (-g option) means it is downloaded to a location so it can be used by anything on your system Ie grunt_cli

The program files directory on windows is protected so you will need to run the command as an administrator, or run npm install from a non protect path such as c:\\myapp

You might want to look at a package.json file, this is a file that allows you to list all your modules that you need for your app. Running just npm install in a location that contains a package.json will cause npm to read the file and download all your dependent modules for you.