<!doctype html> <html> <title>folders</title> <meta http-equiv="content-type" value="text/html;utf-8"> <link rel="stylesheet" type="text/css" href="../static/style.css"> <body> <div id="wrapper"> <h1><a href="../doc/folders.html">folders</a></h1> <p>Folder Structures Used by npm</p> <h2 id="DESCRIPTION">DESCRIPTION</h2> <p>npm puts various things on your computer. That's its job.</p> <p>This document will tell you what it puts where.</p> <h3 id="tl-dr">tl;dr</h3> <ul><li>Local install (default): puts stuff in <code>./node_modules</code> of the current package root.</li><li>Global install (with <code>-g</code>): puts stuff in /usr/local or wherever node is installed.</li><li>Install it <strong>locally</strong> if you're going to <code>require()</code> it.</li><li>Install it <strong>globally</strong> if you're going to run it on the command line.</li><li>If you need both, then install it in both places, or use <code>npm link</code>.</li></ul> <h3 id="prefix-Configuration">prefix Configuration</h3> <p>The <code>prefix</code> config defaults to the location where node is installed. On most systems, this is <code>/usr/local</code>, and most of the time is the same as node's <code>process.installPrefix</code>.</p> <p>On windows, this is the exact location of the node.exe binary. On Unix systems, it's one level up, since node is typically installed at <code>{prefix}/bin/node</code> rather than <code>{prefix}/node.exe</code>.</p> <p>When the <code>global</code> flag is set, npm installs things into this prefix. When it is not set, it uses the root of the current package, or the current working directory if not in a package already.</p> <h3 id="Node-Modules">Node Modules</h3> <p>Packages are dropped into the <code>node_modules</code> folder under the <code>prefix</code>. When installing locally, this means that you can <code>require("packagename")</code> to load its main module, or <code>require("packagename/lib/path/to/sub/module")</code> to load other modules.</p> <p>Global installs on Unix systems go to <code>{prefix}/lib/node_modules</code>. Global installs on Windows go to <code>{prefix}/node_modules</code> (that is, no <code>lib</code> folder.)</p> <p>If you wish to <code>require()</code> a package, then install it locally.</p> <h3 id="Executables">Executables</h3> <p>When in global mode, executables are linked into <code>{prefix}/bin</code> on Unix, or directly into <code>{prefix}</code> on Windows.</p> <p>When in local mode, executables are linked into <code>./node_modules/.bin</code> so that they can be made available to scripts run through npm. (For example, so that a test runner will be in the path when you run <code>npm test</code>.)</p> <h3 id="Man-Pages">Man Pages</h3> <p>When in global mode, man pages are linked into <code>{prefix}/share/man</code>.</p> <p>When in local mode, man pages are not installed.</p> <p>Man pages are not installed on Windows systems.</p> <h3 id="Cache">Cache</h3> <p>See <code><a href="../doc/cache.html">cache(1)</a></code>. Cache files are stored in <code>~/.npm</code> on Posix, or <code>~/npm-cache</code> on Windows.</p> <p>This is controlled by the <code>cache</code> configuration param.</p> <h3 id="Temp-Files">Temp Files</h3> <p>Temporary files are stored by default in the folder specified by the <code>tmp</code> config, which defaults to the TMPDIR, TMP, or TEMP environment variables, or <code>/tmp</code> on Unix and <code>c:\windows\temp</code> on Windows.</p> <p>Temp files are given a unique folder under this root for each run of the program, and are deleted upon successful exit.</p> <h2 id="More-Information">More Information</h2> <p>When installing locally, npm first tries to find an appropriate <code>prefix</code> folder. This is so that <code>npm install foo@1.2.3</code> will install to the sensible root of your package, even if you happen to have <code>cd</code>ed into some other folder.</p> <p>Starting at the $PWD, npm will walk up the folder tree checking for a folder that contains either a <code>package.json</code> file, or a <code>node_modules</code> folder. If such a thing is found, then that is treated as the effective "current directory" for the purpose of running npm commands. (This behavior is inspired by and similar to git's .git-folder seeking logic when running git commands in a working dir.)</p> <p>If no package root is found, then the current folder is used.</p> <p>When you run <code>npm install foo@1.2.3</code>, then the package is loaded into the cache, and then unpacked into <code>./node_modules/foo</code>. Then, any of foo's dependencies are similarly unpacked into <code>./node_modules/foo/node_modules/...</code>.</p> <p>Any bin files are symlinked to <code>./node_modules/.bin/</code>, so that they may be found by npm scripts when necessary.</p> <h3 id="Global-Installation">Global Installation</h3> <p>If the <code>global</code> configuration is set to true, then npm will install packages "globally".</p> <p>For global installation, packages are installed roughly the same way, but using the folders described above.</p> <h3 id="Cycles-Conflicts-and-Folder-Parsimony">Cycles, Conflicts, and Folder Parsimony</h3> <p>Cycles are handled using the property of node's module system that it walks up the directories looking for <code>node_modules</code> folders. So, at every stage, if a package is already installed in an ancestor <code>node_modules</code> folder, then it is not installed at the current location.</p> <p>Consider the case above, where <code>foo -> bar -> baz</code>. Imagine if, in addition to that, baz depended on bar, so you'd have: <code>foo -> bar -> baz -> bar -> baz ...</code>. However, since the folder structure is: <code>foo/node_modules/bar/node_modules/baz</code>, there's no need to put another copy of bar into <code>.../baz/node_modules</code>, since when it calls require("bar"), it will get the copy that is installed in <code>foo/node_modules/bar</code>.</p> <p>This shortcut is only used if the exact same version would be installed in multiple nested <code>node_modules</code> folders. It is still possible to have <code>a/node_modules/b/node_modules/a</code> if the two "a" packages are different versions. However, without repeating the exact same package multiple times, an infinite regress will always be prevented.</p> <p>Another optimization can be made by installing dependencies at the highest level possible, below the localized "target" folder.</p> <h4 id="Example">Example</h4> <p>Consider this dependency graph:</p> <pre><code>foo +-- blerg@1.2.5 +-- bar@1.2.3 | +-- blerg@1.x (latest=1.3.7) | +-- baz@2.x | | `-- quux@3.x | | `-- bar@1.2.3 (cycle) | `-- asdf@* `-- baz@1.2.3 `-- quux@3.x `-- bar</code></pre> <p>In this case, we might expect a folder structure like this:</p> <pre><code>foo +-- node_modules +-- blerg (1.2.5) <---[A] +-- bar (1.2.3) <---[B] | +-- node_modules | | `-- baz (2.0.2) <---[C] | | `-- node_modules | | `-- quux (3.2.0) | `-- asdf (2.3.4) `-- baz (1.2.3) <---[D] `-- node_modules `-- quux (3.2.0) <---[E]</code></pre> <p>Since foo depends directly on bar@1.2.3 and baz@1.2.3, those are installed in foo's <code>node_modules</code> folder.</p> <p>Even though the latest copy of blerg is 1.3.7, foo has a specific dependency on version 1.2.5. So, that gets installed at [A]. Since the parent installation of blerg satisfie's bar's dependency on blerg@1.x, it does not install another copy under [B].</p> <p>Bar [B] also has dependencies on baz and asdf, so those are installed in bar's <code>node_modules</code> folder. Because it depends on <code>baz@2.x</code>, it cannot re-use the <code>baz@1.2.3</code> installed in the parent <code>node_modules</code> folder [D], and must install its own copy [C].</p> <p>Underneath bar, the <code>baz->quux->bar</code> dependency creates a cycle. However, because <code>bar</code> is already in <code>quux</code>'s ancestry [B], it does not unpack another copy of bar into that folder.</p> <p>Underneath <code>foo->baz</code> [D], quux's [E] folder tree is empty, because its dependency on bar is satisfied by the parent folder copy installed at [B].</p> <p>For a graphical breakdown of what is installed where, use <code>npm ls</code>.</p> <h3 id="Publishing">Publishing</h3> <p>Upon publishing, npm will look in the <code>node_modules</code> folder. If any of the items there are not in the <code>bundledDependencies</code> array, then they will not be included in the package tarball.</p> <p>This allows a package maintainer to install all of their dependencies (and dev dependencies) locally, but only re-publish those items that cannot be found elsewhere. See <code><a href="../doc/json.html">json(1)</a></code> for more information.</p> <h2 id="SEE-ALSO">SEE ALSO</h2> <ul><li><a href="../doc/faq.html">faq(1)</a></li><li><a href="../doc/json.html">json(1)</a></li><li><a href="../doc/install.html">install(1)</a></li><li><a href="../doc/pack.html">pack(1)</a></li><li><a href="../doc/cache.html">cache(1)</a></li><li><a href="../doc/config.html">config(1)</a></li><li><a href="../doc/publish.html">publish(1)</a></li></ul> </div> <p id="footer">folders — npm@1.1.55</p> <script> ;(function () { var wrapper = document.getElementById("wrapper") var els = Array.prototype.slice.call(wrapper.getElementsByTagName("*"), 0) .filter(function (el) { return el.parentNode === wrapper && el.tagName.match(/H[1-6]/) && el.id }) var l = 2 , toc = document.createElement("ul") toc.innerHTML = els.map(function (el) { var i = el.tagName.charAt(1) , out = "" while (i > l) { out += "<ul>" l ++ } while (i < l) { out += "</ul>" l -- } out += "<li><a href='#" + el.id + "'>" + ( el.innerText || el.text || el.innerHTML) + "</a>" return out }).join("\n") toc.id = "toc" document.body.appendChild(toc) })() </script> </body></html>