Ubuntu Manpage: npm-install - Install a package

NAME

       npm-install - Install a package

SYNOPSIS

       npm install (with no args in a package dir)
       npm install <tarball file>
       npm install <tarball url>
       npm install <folder>
       npm install <name> [--save|--save-dev|--save-optional]
       npm install <name>@<tag>
       npm install <name>@<version>
       npm install <name>@<version range>
       npm i (with any of the previous argument usage)

DESCRIPTION

       npm  help  This  command  installs  a  package, and any packages that it depends on. If the package has a
       shrinkwrap file, the installation of dependencies will be driven by that. See npm-shrinkwrap.

       A package is:

       •   a) a folder containing a program described by a package.json file

       •   b) a gzipped tarball containing (a)

       •   c) a url that resolves to (b)

       •   d) a <name>@<version> that is published on the registry with (c)

       •   e) a <name>@<tag> that points to (d)

       •   f) a <name> that has a "latest" tag satisfying (e)

       •   g) a <git remote url> that resolves to (b)

       Even if you never publish your package, you can still get a lot of benefits of using npm if you just want
       to write a node program (a), and perhaps if you also want to be able to easily install it elsewhere after
       packing it up into a tarball (b).

       •   npm install (in package directory, no arguments):

           Install the dependencies in the local node_modules folder.

           In global mode (ie, with -g or --global appended to the command), it  installs  the  current  package
           context (ie, the current working directory) as a global package.

       •   npm install <folder>:

           Install a package that is sitting in a folder on the filesystem.

       •   npm install <tarball file>:

           Install  a  package that is sitting on the filesystem. Note: if you just want to link a dev directory
           into your npm root, you can do this more easily by using npm link.

           Example:

               npm install ./package.tgz

       •   npm install <tarball url>:

           Fetch the tarball url, and then install it. In order to distinguish between this and  other  options,
           the argument must start with "http://" or "https://"

           Example:

               npm install https://github.com/indexzero/forever/tarball/v0.5.6

       •   npm install <name> [--save|--save-dev|--save-optional]:

           Do a <name>@<tag> install, where <tag> is the "tag" config. (npm help  See npm-config.)

           In most cases, this will install the latest version of the module published on npm.

           Example:

               npm install sax

       npm  install  takes  3  exclusive,  optional  flags which save or update the package version in your main
       package.json:

       •   --save: Package will appear in your dependencies.

       •   --save-dev: Package will appear in your devDependencies.

       •   --save-optional: Package will appear in your optionalDependencies.

       Examples:

               npm install sax --save
               npm install node-tap --save-dev
               npm install dtrace-provider --save-optional

       Note: If there is a file or folder named <name> in the current working directory, then  it  will  try  to
       install that, and only try to fetch the package by name if it is not valid.

       •   npm install <name>@<tag>:

           Install the version of the package that is referenced by the specified tag. If the tag does not exist
           in the registry data for that package, then this will fail.

           Example:

               npm install sax@latest

       •   npm install <name>@<version>:

           Install the specified version of the package. This will fail if the version has not been published to
           the registry.

           Example:

               npm install sax@0.1.1

       •   npm install <name>@<version range>:

           npm help  Install a version of the package matching the specified version range. This will follow the
           same rules for resolving dependencies described in package.json.

           Note  that  most  version  ranges  must be put in quotes so that your shell will treat it as a single
           argument.

           Example:

               npm install sax@">=0.1.0 <0.2.0"

       •   npm install <git remote url>:

           Install a package by cloning a git remote url. The format of the git url is:

               <protocol>://[<user>@]<hostname><separator><path>[#<commit-ish>]

       <protocol> is one of git, git+ssh, git+http, or git+https. If no <commit-ish> is specified,  then  master
       is used.

       Examples:

               git+ssh://git@github.com:isaacs/npm.git#v1.0.27
               git+https://isaacs@github.com/isaacs/npm.git
               git://github.com/isaacs/npm.git#v1.0.27

       You may combine multiple arguments, and even multiple types of arguments. For example:

           npm install sax@">=0.1.0 <0.2.0" bench supervisor

       The --tag argument will apply to all of the specified install targets.

       The --force argument will force npm to fetch remote resources even if a local copy exists on disk.

           npm install sax --force

       npm  help   The --global argument will cause npm to install the package globally rather than locally. See
       npm-folders.

       The --link argument will cause npm to link global installs into the local space in some cases.

       The --no-bin-links argument will prevent npm from creating symlinks for any binaries  the  package  might
       contain.

       The  --no-shrinkwrap  argument,  which  will ignore an available shrinkwrap file and use the package.json
       instead.

       The --nodedir=/path/to/node/source argument will allow npm to find the node source code so that  npm  can
       compile native modules.

       npm help  See npm-config. Many of the configuration params have some effect on installation, since that´s
       most of what npm does.

ALGORITHM

       To install a package, npm uses the following algorithm:

           install(where, what, family, ancestors)
           fetch what, unpack to <where>/node_modules/<what>
           for each dep in what.dependencies
             resolve dep to precise version
           for each dep@version in what.dependencies
               not in <where>/node_modules/<what>/node_modules/*
               and not in <family>
             add precise version deps to <family>
             install(<where>/node_modules/<what>, dep, family)

       For this package{dep} structure: A{B,C}, B{C}, C{D}, this algorithm produces:

           A
           +-- B
           `-- C
               `-- D

       That is, the dependency from B to C is satisfied by the fact that A already caused C to be installed at a
       higher level.

       npm  help   See  npm-folders  for  a more detailed description of the specific folder structures that npm
       creates.

   Limitations of npm´s Install Algorithm
       There are some very rare and pathological edge-cases where a cycle can cause npm  to  try  to  install  a
       never-ending tree of packages. Here is the simplest case:

           A -> B -> A´ -> B´ -> A -> B -> A´ -> B´ -> A -> ...

       where  A  is  some  version  of  a  package, and A´ is a different version of the same package. Because B
       depends on a different version of A than the one that is already in the tree, it must install a  separate
       copy.  The  same  is  true of A´, which must install B´. Because B´ depends on the original version of A,
       which has been overridden, the cycle falls into infinite regress.

       To avoid this situation, npm flat-out refuses  to  install  any  name@version  that  is  already  present
       anywhere  in the tree of package folder ancestors. A more correct, but more complex, solution would be to
       symlink the existing version into the new location. If this ever affects a  real  use-case,  it  will  be
       investigated.

NAME

SYNOPSIS

DESCRIPTION

ALGORITHM

SEE ALSO