Node js check if file exists

Question

How do i check the existence of a file   In the documentation for the module fs there s a description of the method fs exists path  callback   But  as I understand  it checks for the existence of only directories  And I need to check the file   How can this be done

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A easier way to do this synchronously     if  fs existsSync   etc file          console log  Found file        The API doc says how existsSync work  Test whether or not the given path exists by checking with the file system

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For asynchronous version  And with the promise version  Here the clean simple way   try       await fsPromise stat filePath                  File exists                 do something   catch  err        if  err code    ENOENT                           File not found                  else              Another error            A more practical snippet from my code to illustrate better    try       const filePath   path join FILES DIR  fileName       await fsPromise stat filePath                  File exists              const readStream   fs createReadStream          filePath                        autoClose  true              start  0                       return           success  true          readStream          catch  err                   Mapped file doesn t exists             if  err code    ENOENT             return               err                    msg   Mapped file doesn  t exists                   code  EErrorCode MappedFileNotFound                                else           return               err                    msg   Mapped file failed to load  File system error                   code  EErrorCode MappedFileFileSystemError                                    The example above is just for demonstration  I could have used the error event of the read stream  To catch any errors  And skip the two calls

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There are a lot of inaccurate comments about fs existsSync   being deprecated  it is not   https   nodejs org api fs html fs fs existssync path     Note that fs exists   is deprecated  but fs existsSync   is not

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Modern async await way   Node 12 8 x    const fileExists   async path   gt     await fs promises stat path  catch e   gt  false     const main   async      gt        console log await fileExists   path myfile txt        main      We need to use fs stat   or fs access   because fs exists path  callback  now is deprecated  Another good way is fs-extra

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in old days before sit down I always check if chair is there then I sit else I have an alternative plan like sit on a coach  Now node js site suggest just go  no needs to check  and the answer looks like this        fs readFile    foo txt   function  err  data               if err                   if  err code      ENOENT                          console log   File Doesn  t Exist                 return                    if  err code      EACCES                          console log   No Permission                 return                           console log   Unknown Error             return                console log  data               code taken from http   fredkschott com post 2014 03 understanding-error-first-callbacks-in-node-js  from March 2014  and slightly modified to fit computer  It checks for permission as well - remove permission for to test chmod a-r foo txt

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Why not just try opening the file   fs open  YourFile    a   function  err  fd           anyway after a minute search try this    var path   require  path      path exists  foo txt   function exists       if  exists            do something                or   if  path existsSync  foo txt            do something          For Node js v0 12 x and higher   Both path exists and fs exists have been deprecated   Edit   Changed  else if err code     ENOENT    to  else if err code      ENOENT    Linter complains about the double equals not being the triple equals   Using fs stat   fs stat  foo txt   function err  stat        if err    null            console log  File exists          else if err code      ENOENT                file does not exist         fs writeFile  log txt    Some log n          else           console log  Some other error     err code

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fs exists path  callback  and fs existsSync path  are deprecated now  see https   nodejs org api fs html fs fs exists path callback and https   nodejs org api fs html fs fs existssync path   To test the existence of a file synchronously one can use ie  fs statSync path   An fs Stats object will be returned if the file exists  see https   nodejs org api fs html fs class fs stats  otherwise an error is thrown which will be catched by the try   catch statement   var fs   require  fs      path     path to my file     stats   try     stats   fs statSync path     console log  File exists       catch  e      console log  File does not exist

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Using typescript and fs promises in node14 import   as fsp from  fs promises   try  const   await fsp readFile fullFileName        catch e          It is better to use fsp readFile than fsp stator fsp access for two reasons   The least important reason - it is one less access  It is possible that fsp statand fsp readFile would give different answers   Either due to subtle differences in the questions they ask  or because the files status changed between the calls   So the coder would have to code for two conditional branches instead of one  and the user might see more behaviors

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fs exists has been deprecated since 1 0 0  You can use fs stat instead of that   var fs   require  fs    fs stat path   err  stats    gt    if    stats isFile filename         do this      else      do this         Here is the link for the documentation fs stats

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You can use fs stat to check if target is a file or directory and you can use fs access to check if you can write read execute the file   remember to use path resolve to get full path for the target   Documentation    path resolve fs stat fs access   Full example  TypeScript   import   as fs from  fs   import   as path from  path    const targetPath   path resolve process argv 2     function statExists checkPath   Promise lt fs Stats gt      return new Promise  resolve    gt        fs stat checkPath   err  result    gt          if  err            return resolve undefined                  return resolve result                    function checkAccess checkPath  string  mode  number   fs constants F OK   Promise lt boolean gt      return new Promise  resolve    gt        fs access checkPath  mode   err    gt          resolve  err                     async function        const result   await statExists targetPath     const accessResult   await checkAccess targetPath  fs constants F OK     const readResult   await checkAccess targetPath  fs constants R OK     const writeResult   await checkAccess targetPath  fs constants W OK     const executeResult   await checkAccess targetPath  fs constants X OK     const allAccessResult   await checkAccess targetPath  fs constants F OK   fs constants R OK   fs constants W OK   fs constants X OK      if  result        console group  stat        console log  isFile     result isFile         console log  isDir     result isDirectory         console groupEnd          else       console log  file dir does not exist           console group  access      console log  access    accessResult     console log  read access    readResult     console log  write access    writeResult     console log  execute access    executeResult     console log  all  combined  access    allAccessResult     console groupEnd       process exit 0

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vannilla Nodejs callback function fileExists path  cb     return fs access path  fs constants F OK  er  result   gt  cb  err  amp  amp  result     F OK checks if file is visible  is default does no need to be specified     the docs say you should use access   as a replacement for deprecated exists   Nodejs with build in promise  node 7   function fileExists path  cb     return new Promise  accept deny    gt       fs access path  fs constants F OK  er  result   gt  cb  err  amp  amp  result           Popular javascript framework fs-extra var fs   require  fs-extra   await fs pathExists filepath   As you see much simpler  And the advantage over promisify is that you have complete typings with this package  complete intellisense typescript   Most of the cases you will have already included this library because   -10 000  other libraries depend on it

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Fox  great answer  Here s a bit of an extension with some more options   It s what I ve been using lately as a go-to solution   var fs   require  fs     fs lstat  targetPath  function  err  inodeStatus      if  err            file does not exist-     if  err code      ENOENT            console log  No file or directory at  targetPath         return                miscellaneous error  e g  permissions      console error err       return             Check if this is a file or directory   var isDirectory   inodeStatus isDirectory           Get file size           NOTE  this won t work recursively for directories-- see       http   stackoverflow com a 7550430 486547        var sizeInBytes   inodeStatus size     console log       isDirectory    Folder     File         at  targetPath       is  sizeInBytes  bytes              P S  check out fs-extra if you aren t already using it-- it s pretty sweet  https   github com jprichardson node-fs-extra

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async await version using util promisify as of Node 8   const fs   require  fs    const   promisify     require  util    const stat   promisify fs stat    describe  async stat        gt      it  should not throw if file does exist   async      gt        try         const stats   await stat path join  path    to    existingfile txt           assert notEqual stats  null         catch  err             shouldn t happen                  describe  async stat        gt      it  should throw if file does not exist   async      gt        try         const stats   await stat path join  path    to    not    existingfile txt           catch  err          assert notEqual err  null

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Well I did it this way  as seen on https   nodejs org api fs html fs fs access path mode callback  fs access    settings   fs constants F OK   fs constants R OK   fs constants W OK  function err     console log err    no access or dir doesnt exist     R W ok       if err  amp  amp  err code      ENOENT        fs mkdir  settings              Is there any problem with this

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Edit  Since node v10 0 0we could use fs promises access      Example async code that checks if file exists  async function checkFileExists file      return fs promises access file  fs constants F OK              then      gt  true              catch      gt  false      An alternative for stat might be using the new fs access       minified short promise function for checking  s   gt  new Promise r  gt fs access s  fs constants F OK  e   gt  r  e     Sample usage  let checkFileExists   s   gt  new Promise r  gt fs access s  fs constants F OK  e   gt  r  e    checkFileExists  quot Some File Location quot      then bool   gt  console log   file exists    bool       expanded Promise way     returns a promise which resolves true if file exists  function checkFileExists filepath     return new Promise  resolve  reject    gt        fs access filepath  fs constants F OK  error   gt          resolve  error                    or if you wanna do it synchronously  function checkFileExistsSync filepath     let flag   true    try      fs accessSync filepath  fs constants F OK      catch e       flag   false        return flag

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Old Version before V6   here s the documentation    const fs   require  fs          fs exists   etc passwd    exists    gt         console log exists    it  s there     no passwd              or Sync    if  fs existsSync   etc passwd          console log  it  s there          UPDATE   New versions from V6  documentation for fs stat  fs stat   etc passwd   function err  stat        if err    null              Exist       else if err code     ENOENT                NO exist

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After a bit of experimentation  I found the following example using fs stat to be a good way to asynchronously check whether a file exists  It also checks that your  file  is  really-is-a-file   and not a directory    This method uses Promises  assuming that you are working with an asynchronous codebase   const fileExists   path   gt      return new Promise  resolve  reject    gt        try         fs stat path   error  file    gt            if   error  amp  amp  file isFile                return resolve true                      if  error  amp  amp  error code      ENOENT               return resolve false                             catch  err          reject err                    If the file does not exist  the promise still resolves  albeit false  If the file does exist  and it is a directory  then is resolves true  Any errors attempting to read the file will reject the promise the error itself

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fs statSync path  function err  stat         if err    null              console log  File exists                code when all ok        else if  err code     ENOENT               file doesn t exist         console log  not file                   else           console log  Some other error     err code

[node.js] Node.js check if file exists

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