Node js create folder or use existing

Question

I already have read the documentation of Node js and  unless if I missed something  it does not tell what the parameters contain in certain operations  in particular fs mkdir    As you can see in the documentation  it s not very much   Currently  I have this code  which tries to create a folder or use an existing one instead   fs mkdir path function e       if  e     e  amp  amp  e code      EEXIST               do something with contents       else             debug         console log e               But I wonder is this the right way to do it  Is checking for the code EEXIST the right way to know that the folder already exists  I know I can do fs stat   before making the directory  but that would already be two hits to the filesystem   Secondly  is there a complete or at least a more detailed documentation of Node js that contains details as to what error objects contain  what parameters signify etc

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You can use this   if  fs existsSync  directory         fs mkdirSync  directory   0766  function err           if err               console log err                  echo the result back             response send  ERROR  Can t make the directory   n

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Here is the ES6 code which I use to create a directory  when it doesn t exist    const fs   require  fs    const path   require  path     function createDirectory directoryPath      const directory   path normalize directoryPath      return new Promise  resolve  reject    gt        fs stat directory   error    gt          if  error            if  error code      ENOENT               fs mkdir directory   error    gt                if  error                  reject error                 else                 resolve directory                                         else             reject error                     else           resolve directory                            const directoryPath        dirname  test    createDirectory directoryPath  then  path    gt      console log  Successfully created directory     path         catch  error    gt      console log  Problem creating directory    error message          Note    In the beginning of the createDirectory function  I normalize the path to guarantee that the path seperator type of the operating system will be used consistently  e g  this will turn C  directory test into C  directory test  when being on Windows  fs exists is deprecated  that s why I use fs stat to check if the directory already exists If a directory doesn t exist  the error code will be ENOENT  Error NO ENTry  The directory itself will be created using fs mkdir I prefer the asynchronous function fs mkdir over it s blocking counterpart fs mkdirSync and because of the wrapping Promise it will be guaranteed that the path of the directory will only be returned after the directory has been successfully created

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You can also use fs-extra  which provide a lot frequently used file operations   Sample Code   var fs   require  fs-extra    fs mkdirs   tmp some long path that prob doesnt exist   function  err      if  err  return console error err    console log  success        fs mkdirsSync   tmp another path     docs here  https   github com jprichardson node-fs-extra mkdirsdir-callback

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You d better not to count the filesystem hits while you code in Javascript  in my opinion  However   1  stat  amp  mkdir and  2  mkdir and check or discard  the error code  both ways are right ways to do what you want

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Edit  Because this answer is very popular  I have updated it to reflect up-to-date practices   Node   10  The new   recursive  true   option of Node s fs now allows this natively  This option mimics the behaviour of UNIX s mkdir -p  It will recursively make sure every part of the path exist  and will not throw an error if any of them do    Note  it might still throw errors such as EPERM or EACCESS  so better still wrap it in a try    catch  e     if your implementation is susceptible to it    Synchronous version   fs mkdirSync dirpath    recursive  true      Async version  await fs promises mkdir dirpath    recursive  true      Older Node versions  Using a try    catch  err      you can achieve this very gracefully without encountering a race condition   In order to prevent dead time between checking for existence and creating the directory  we simply try to create it straight up  and disregard the error if it is EEXIST  directory already exists    If the error is not EEXIST  however  we ought to throw an error  because we could be dealing with something like an EPERM or EACCES  function ensureDirSync  dirpath      try       return fs mkdirSync dirpath      catch  err        if  err code      EEXIST   throw err         For mkdir -p-like recursive behaviour  e g    a b c  you d have to call it on every part of the dirpath  e g    a    a b   a b c

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Raugaral s answer but with -p functionality  Ugly  but it works   function mkdirp dir        let dirs   dir split       filter asdf   gt   asdf match    s          let fullpath              Production directory will begin     test is on my local drive      if  dirs 0  match  C  i             fullpath   dirs 0                   else           fullpath            dirs 0                       Start from root directory   1  build out one level at a time      dirs slice 1  map asdf   gt            fullpath    asdf                if   fs existsSync fullpath                 fs mkdirSync fullpath                      mkdirp

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Good way to do this is to use mkdirp module     npm install mkdirp   Use it to run function that requires the directory  Callback is called after path is created or if path did already exists  Error err is set if mkdirp failed to create directory path   var mkdirp   require  mkdirp    mkdirp   tmp some path foo   function err             path exists unless there was an error

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You can do all of this with the File System module   const   fs   require  fs      dirPath    path to dir      Check if directory exists  fs access dirPath  fs constants F OK   err   gt     if  err          Create directory if directory does not exist      fs mkdir dirPath   recursive true    err   gt         if  err  console log  Error creating directory    err          else console log  Directory created successfully                    Directory now exists       You really don t even need to check if the directory exists  The following code also guarantees that the directory either already exists or is created   const   fs   require  fs      dirPath    path to dir      Create directory if directory does not exist  fs mkdir dirPath   recursive true    err   gt     if  err  console log  Error creating directory    err         Directory now exists

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I propose a solution without modules  accumulate modules is never recommended for maintainability especially for small functions that can be written in a few lines        LAST UPDATE    In v10 12 0  NodeJS impletement recursive options       Create recursive folder fs mkdir  my new folder create     recursive  true     err    gt    if  err  throw err        UPDATE       Get modules node const fs     require  fs    const path   require  path        Create  function mkdirpath dirPath        if  fs accessSync dirPath  fs constants R OK   fs constants W OK                 try                       fs mkdirSync dirPath                     catch e                        mkdirpath path dirname dirPath                mkdirpath dirPath                         Create folder path mkdirpath  my new folder create

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If you want a quick-and-dirty one liner  use this   fs existsSync  directory      fs mkdirSync  directory

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create dynamic name directory for each user    use this code      suppose email contain user mail address     var filessystem   require  fs    var dir      public uploads   email   if   filessystem existsSync dir      filessystem mkdirSync dir     else       console log  Directory already exist

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The node js docs for fs mkdir basically defer to the Linux man page for mkdir 2    That indicates that EEXIST will also be indicated if the path exists but isn t a directory which creates an awkward corner case if you go this route   You may be better off calling fs stat which will tell you whether the path exists and if it s a directory in a single call   For  what I m assuming is  the normal case where the directory already exists  it s only a single filesystem hit   These fs module methods are thin wrappers around the native C APIs so you ve got to check the man pages referenced in the node js docs for the details

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Liberateur s answer above did not work for me  Node v8 10 0    Little modification did the trick but I am not sure if this is a right way  Please suggest      Get modules node const fs     require  fs    const path   require  path        Create function mkdirpath dirPath        try           fs accessSync dirPath  fs constants R OK   fs constants W OK             catch err            try                       fs mkdirSync dirPath                     catch e                        mkdirpath path dirname dirPath                mkdirpath dirPath                         Create folder path mkdirpath  my new folder create

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Just as a newer alternative to Teemu Ikonen s answer  which is very simple and easily readable  is to use the ensureDir method of the fs-extra package   It can not only be used as a blatant replacement for the built in fs module  but also has a lot of other functionalities in addition to the functionalities of the fs package    The ensureDir method  as the name suggests  ensures that the directory exists  If the directory structure does not exist  it is created  Like mkdir -p  Not just the end folder  instead the entire path is created if not existing already    the one provided above is the async version of it  It also has a synchronous method to perform this in the form of the ensureDirSync method

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