How to Find the Size of All Files Located Inside a Folder

linux command to get size of files and directories present in a particular folder?

Use ls command for files and du command for directories.

Checking File Sizes

ls -l filename   #Displays Size of the specified file
ls -l *          #Displays Size of All the files in the current directory
ls -al *         #Displays Size of All the files including hidden files in the current directory
ls -al dir/      #Displays Size of All the files including hidden files in the 'dir' directory

ls command will not list the actual size of directories(why?). Therefore, we use du for this purpose.

Checking Directory sizes

du -sh directory_name    #Gives you the summarized(-s) size of the directory in human readable(-h) format
du -bsh *                #Gives you the apparent(-b) summarized(-s) size of all the files and directories in the current directory in human readable(-h) format

Including -h option in any of the above commands (for Ex: ls -lh * or du -sh) will give you size in human readable format (kb, mb,gb, ...)

For more information see man ls and man du

Get size of folder or file

java.io.File file = new java.io.File("myfile.txt");
file.length();

This returns the length of the file in bytes or 0 if the file does not exist. There is no built-in way to get the size of a folder, you are going to have to walk the directory tree recursively (using the listFiles() method of a file object that represents a directory) and accumulate the directory size for yourself:

public static long folderSize(File directory) {
    long length = 0;
    for (File file : directory.listFiles()) {
        if (file.isFile())
            length += file.length();
        else
            length += folderSize(file);
    }
    return length;
}

WARNING: This method is not sufficiently robust for production use. directory.listFiles() may return null and cause a NullPointerException. Also, it doesn't consider symlinks and possibly has other failure modes. Use this method.

Get Folder Size from Windows Command Line

You can just add up sizes recursively (the following is a batch file):

@echo off
set size=0
for /r %%x in (folder\*) do set /a size+=%%~zx
echo %size% Bytes

However, this has several problems because cmd is limited to 32-bit signed integer arithmetic. So it will get sizes above 2 GiB wrong¹. Furthermore it will likely count symlinks and junctions multiple times so it's at best an upper bound, not the true size (you'll have that problem with any tool, though).

An alternative is PowerShell:

Get-ChildItem -Recurse | Measure-Object -Sum Length

or shorter:

ls -r | measure -sum Length

If you want it prettier:

switch((ls -r|measure -sum Length).Sum) {
  {$_ -gt 1GB} {
    '{0:0.0} GiB' -f ($_/1GB)
    break
  }
  {$_ -gt 1MB} {
    '{0:0.0} MiB' -f ($_/1MB)
    break
  }
  {$_ -gt 1KB} {
    '{0:0.0} KiB' -f ($_/1KB)
    break
  }
  default { "$_ bytes" }
}

You can use this directly from cmd:

powershell -noprofile -command "ls -r|measure -sum Length"

¹ I do have a partially-finished bignum library in batch files somewhere which at least gets arbitrary-precision integer addition right. I should really release it, I guess :-)

How can I find the size of all files located inside a folder?

Actually I don't want to use any third party library. Just want to
implement in pure c++.

If you use MSVC++ you have <filesystem> "as standard C++".
But using boost or MSVC - both are "pure C++".

If you don’t want to use boost, and only the C++ std:: library this answer is somewhat close. As you can see here, there is a Filesystem Library Proposal (Revision 4). Here you can read:

The Boost version of the library has been in widespread use for ten
years. The Dinkumware version of the library, based on N1975
(equivalent to version 2 of the Boost library), ships with Microsoft
Visual C++ 2012.

To illustrate the use, I adapted the answer of @Nayana Adassuriya , with very minor modifications (OK, he forgot to initialize one variable, and I use unsigned long long, and most important was to use: path filePath(complete (dirIte->path(), folderPath)); to restore the complete path before the call to other functions). I have tested and it work well in windows 7.

#include <iostream>
#include <string>
#include <filesystem>
using namespace std;
using namespace std::tr2::sys;

void  getFoldersize(string rootFolder,unsigned long long & f_size)
{
   path folderPath(rootFolder);                      
   if (exists(folderPath))
   {
        directory_iterator end_itr;
        for (directory_iterator dirIte(rootFolder); dirIte != end_itr; ++dirIte )
        {
            path filePath(complete (dirIte->path(), folderPath));
           try{
                  if (!is_directory(dirIte->status()) )
                  {
                      f_size = f_size + file_size(filePath);                      
                  }else
                  {
                      getFoldersize(filePath,f_size);
                  }
              }catch(exception& e){  cout << e.what() << endl; }
         }
      }
    }

int main()
{
    unsigned long long  f_size=0;
    getFoldersize("C:\\Silvio",f_size);
    cout << f_size << endl;
    system("pause");
    return 0;
}

ASP.NET: Fast way to get file size and count of all files?

Try dumping recursion, and try dumping linq - it is slow and eats up a lot of memory.

Try this:

  Dim strFolder = "C:\Users\AlbertKallal\Desktop"

    Dim MyDir As New DirectoryInfo(strFolder)
    Dim MyFiles() As FileInfo = MyDir.GetFiles("*.*", SearchOption.AllDirectories)

    For Each MyFile As FileInfo In MyFiles
        tSize += MyFile.Length
    Next

How to list the size of each file and directory and sort by descending size in Bash?

Simply navigate to directory and run following command:

du -a --max-depth=1 | sort -n

OR add -h for human readable sizes and -r to print bigger directories/files first.

du -a -h --max-depth=1 | sort -hr

Trying to get folder sizes for all users directory

The issue you have is that FullName contains a DirectoryInfo object, you have two options;

Change your select to ExpandProperty which will change it to a string of the full path.
Select-Object -ExpandProperty Fullname
Refer to $Root using the property FullName which is a property on the DirectoryInfo Object.
Get-ChildItem -path $Root.FullName -Recurse

This is one solution to what you are trying to achieve, note that errors (e.g. access denied) are ignored.

Get-ChildItem $StorageLocation | ForEach-Object {

    $sizeInMB = (Get-ChildItem $_.FullName -Recurse -ErrorAction SilentlyContinue | Measure-Object -Property Length -Sum -ErrorAction SilentlyContinue).Sum / 1MB

    New-Object PSObject -Property @{
        FullName = $_.FullName
        SizeInMB = $sizeInMB
    }
}