Node.js
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Node.js is a javascript runtime environment combined with useful libraries. It uses Google's V8 engine to execute code outside of the browser. Due to its event-driven, non-blocking I/O model, it is suitable for real-time web applications.
Installation
nodejs package is available in the official repositories.
Alternate Installations
It is not uncommon to need or desire to work in different versions of nodejs. A preferred method among node users is to use NVM (Node Version Manger). nvmAUR allows for cheap and easy alternative installs. Usage is well documented on the projects github but is as simple as:
$ nvm install VERSION_NUM
Node Packaged Modules
npm is the official package manager for node.js. Since nodejs 0.12.2-4, npm
is no longer included in the package. It is available as npm in the official repositories.
Managing packages with npm
Installing packages
Any package can be installed using:
$ npm install packageName
This command installs the package in the current directory under node_modules
and executables under node_modules/.bin
.
For a system-wide installation global switch -g
can be used:
# npm -g install packageName
By default this command installs the package under /usr/lib/node_modules/npm
and requires admin privileges to do so.
For a user-wide installation you can configure npm
to use a local folder instead. This can be done in various ways:
- Manually with the
--prefix
command line flag (e.g.npm -g install packageName --prefix ~/.node_modules
). - Using the
npm_config_prefix
environment variable. - Using a user config file
~/.npmrc
.
First method is not recommended since you need to remember the location and give it as the parameter each time you do an operation.
For the second method simply add the following lines to your shell configuration file (e.g. .bash_profile
).
PATH="$HOME/.node_modules/bin:$PATH" export npm_config_prefix=~/.node_modules
Do not forget to log out and log back in or restart your shell accordingly.
For the third method you can use the command:
$ npm config edit
You can then find the prefix
option and set a desired location:
prefix=~/.node_modules
Do not forget to delete the preceding ;
on the line or it will be read as a comment. You can now add the location of your executables to your shell configuration file (e.g. .bash_profile
).
export PATH="$HOME/.node_modules/bin:$PATH"
Again do not forget to log out and log back in or restart your shell accordingly.
Updating packages
Updating packages is as simple as
$ npm update packageName
For the case of globally installed packages (-g
)
# npm update -g packageName
Updating All Packages
However, sometimes you may just wish to update all packages. Be it locally or globally. Leaving off the packageName npm
will attempt to update all the packages
$ npm update
or add the -g
flag to update globally installed packages
# npm update -g
Removing packages
To remove a package installed with the -g
switch simply use:
# npm -g uninstall packageName
to remove a local package drop the switch and run:
$ npm uninstall packageName
Listing packages
To show a tree view of the installed globally packages use:
$ npm -g list
This tree is often quite deep. To only display the top level packages use:
$ npm list --depth=0
To display obsolete packages that may need to be updated:
$ npm outdated
Managing packages with pacman
Some node.js packages can be found in Arch User Repository with the name nodejs-packageName
.
Troubleshooting
node-gyp python errors
Some node modules use the node-gyp
utility which does not support Python 3, which in most cases will be the default system-wide Python executable. To resolve such errors, make sure you have python2 installed, then set the default npm Python like so:
$ npm config set python /usr/bin/python2
In case of errors like gyp WARN EACCES user "root" does not have permission to access the ... dir --unsafe-perm option might help:
$ sudo npm install --unsafe-perm -g node-inspector
Additional Resources
For further information on nodejs and use of its official package manager npm you may wish to consult the following external resources
- NodeJs Documentation Documentation and Tutorials for Node
- NodeJS Community Webpage
- API Documentation Official
npm
API documentation - IRC channel #node.js on irc.freenode.net