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