How to Get a Human-Readable File Size in Bytes Abbreviation Using .Net

How do I get a human-readable file size in bytes abbreviation using .NET?

This may not the most efficient or optimized way to do it, but it's easier to read if you are not familiar with log maths, and should be fast enough for most scenarios.

string[] sizes = { "B", "KB", "MB", "GB", "TB" };
double len = new FileInfo(filename).Length;
int order = 0;
while (len >= 1024 && order < sizes.Length - 1) {
    order++;
    len = len/1024;
}

// Adjust the format string to your preferences. For example "{0:0.#}{1}" would
// show a single decimal place, and no space.
string result = String.Format("{0:0.##} {1}", len, sizes[order]);

bytes to human readable string

There is always a little confusion about how to display bytes. Your code is correct if the result is what you are trying to achieve.

What you showed from Google is a decimal representation. So just as you say 1000m = 1km, you can say 1000byte = 1kB.

On the other hand, there is the binary representation where 1k = 2^10 = 1024. These representations are called kibiBytes, Gibibytes etc.

Which representation you choose is up to you or the requirements of your customers. Just make obvious which you use to avoid confusion.

How can i display in label the real size of a file on the hard disk?

The nice thing about programming is, that repetative tasks can be automated. A solution that automatically calculates the size could be:

• find file size
• repeat until size is bigger than 1024
• divide size by 1024
• store size position
• loop

The code can look like this:

private String sizeFormatter(Int64 filesize)
{
    var sizes = new List<String> { "B", "KB", "MB", "GB", "TB", "PB" };
    var size = 0;
    while (filesize > 1024)
    {
        filesize /= 1024;
        size++;
    }
    return String.Format("{0}{1}", filesize, sizes[size]);
}

And the usage:

var bigFile = new FileInfo("C:\\oracle\\OracleXE112_Win32.zip");
var smallFile = new FileInfo("C:\\oracle\\ScriptCreateUser.sql");
var verySmallFile = new FileInfo("C:\\ScriptCreateTable.sql");
Console.WriteLine(sizeFormatter(bigFile.Length));
Console.WriteLine(sizeFormatter(smallFile.Length));
Console.WriteLine(sizeFormatter(verySmallFile.Length));

The output is:

312MB
12KB
363B

This method could be optimized regarding accuracy, but for the general usage it should be alright.

File-size format provider

I use this one, I get it from the web

public class FileSizeFormatProvider : IFormatProvider, ICustomFormatter
{
    public object GetFormat(Type formatType)
    {
        if (formatType == typeof(ICustomFormatter)) return this;
        return null;
    }

    private const string fileSizeFormat = "fs";
    private const Decimal OneKiloByte = 1024M;
    private const Decimal OneMegaByte = OneKiloByte * 1024M;
    private const Decimal OneGigaByte = OneMegaByte * 1024M;

    public string Format(string format, object arg, IFormatProvider formatProvider)
    {    
        if (format == null || !format.StartsWith(fileSizeFormat))    
        {    
            return defaultFormat(format, arg, formatProvider);    
        }

        if (arg is string)    
        {    
            return defaultFormat(format, arg, formatProvider);    
        }

        Decimal size;

        try    
        {    
            size = Convert.ToDecimal(arg);    
        }    
        catch (InvalidCastException)    
        {    
            return defaultFormat(format, arg, formatProvider);    
        }

        string suffix;
        if (size > OneGigaByte)
        {
            size /= OneGigaByte;
            suffix = "GB";
        }
        else if (size > OneMegaByte)
        {
            size /= OneMegaByte;
            suffix = "MB";
        }
        else if (size > OneKiloByte)
        {
            size /= OneKiloByte;
            suffix = "kB";
        }
        else
        {
            suffix = " B";
        }

        string precision = format.Substring(2);
        if (String.IsNullOrEmpty(precision)) precision = "2";
        return String.Format("{0:N" + precision + "}{1}", size, suffix);

    }

    private static string defaultFormat(string format, object arg, IFormatProvider formatProvider)
    {
        IFormattable formattableArg = arg as IFormattable;
        if (formattableArg != null)
        {
            return formattableArg.ToString(format, formatProvider);
        }
        return arg.ToString();
    }

}

an example of use would be:

Console.WriteLine(String.Format(new FileSizeFormatProvider(), "File size: {0:fs}", 100));
Console.WriteLine(String.Format(new FileSizeFormatProvider(), "File size: {0:fs}", 10000));

Credits for http://flimflan.com/blog/FileSizeFormatProvider.aspx

There is a problem with ToString(), it's expecting a NumberFormatInfo type that implements IFormatProvider but the NumberFormatInfo class is sealed :(

If you're using C# 3.0 you can use an extension method to get the result you want:

public static class ExtensionMethods
{
    public static string ToFileSize(this long l)
    {
        return String.Format(new FileSizeFormatProvider(), "{0:fs}", l);
    }
}

You can use it like this.

long l = 100000000;
Console.WriteLine(l.ToFileSize());

Hope this helps.

How can I convert byte size into a human-readable format in Java?

Fun fact: The original snippet posted here was the most copied Java snippet of all time on Stack Overflow, and it was flawed. It was fixed, but it got messy.

Full story in this article: The most copied Stack Overflow snippet of all time is flawed!

Source: Formatting byte size to human readable format | Programming.Guide

SI (1 k = 1,000)

public static String humanReadableByteCountSI(long bytes) {
    if (-1000 < bytes && bytes < 1000) {
        return bytes + " B";
    }
    CharacterIterator ci = new StringCharacterIterator("kMGTPE");
    while (bytes <= -999_950 || bytes >= 999_950) {
        bytes /= 1000;
        ci.next();
    }
    return String.format("%.1f %cB", bytes / 1000.0, ci.current());
}

Binary (1 Ki = 1,024)

public static String humanReadableByteCountBin(long bytes) {
    long absB = bytes == Long.MIN_VALUE ? Long.MAX_VALUE : Math.abs(bytes);
    if (absB < 1024) {
        return bytes + " B";
    }
    long value = absB;
    CharacterIterator ci = new StringCharacterIterator("KMGTPE");
    for (int i = 40; i >= 0 && absB > 0xfffccccccccccccL >> i; i -= 10) {
        value >>= 10;
        ci.next();
    }
    value *= Long.signum(bytes);
    return String.format("%.1f %ciB", value / 1024.0, ci.current());
}

Example output:

                             SI     BINARY

                  0:        0 B        0 B
                 27:       27 B       27 B
                999:      999 B      999 B
               1000:     1.0 kB     1000 B
               1023:     1.0 kB     1023 B
               1024:     1.0 kB    1.0 KiB
               1728:     1.7 kB    1.7 KiB
             110592:   110.6 kB  108.0 KiB
            7077888:     7.1 MB    6.8 MiB
          452984832:   453.0 MB  432.0 MiB
        28991029248:    29.0 GB   27.0 GiB
      1855425871872:     1.9 TB    1.7 TiB
9223372036854775807:     9.2 EB    8.0 EiB   (Long.MAX_VALUE)

Get the size, in bytes, of how much a string will occupy when written to a file?

A file may begin with a byte order mark (called BOM) that helps the reader to detect what encoding was used.

The BOM for UTF8 is 3 bytes EF,BB,BF

For UTF16 (Encoding.Unicode) 2 bytes FEFF (encoded as either big endian or little endian depending on the encoding)

For UTF32 4 bytes 0000FEFF

Does .NET provide an easy way convert bytes to KB, MB, GB, etc.?

Here is a fairly concise way to do this:

static readonly string[] SizeSuffixes = 
                   { "bytes", "KB", "MB", "GB", "TB", "PB", "EB", "ZB", "YB" };
static string SizeSuffix(Int64 value, int decimalPlaces = 1)
{
    if (decimalPlaces < 0) { throw new ArgumentOutOfRangeException("decimalPlaces"); }
    if (value < 0) { return "-" + SizeSuffix(-value, decimalPlaces); } 
    if (value == 0) { return string.Format("{0:n" + decimalPlaces + "} bytes", 0); }

    // mag is 0 for bytes, 1 for KB, 2, for MB, etc.
    int mag = (int)Math.Log(value, 1024);

    // 1L << (mag * 10) == 2 ^ (10 * mag) 
    // [i.e. the number of bytes in the unit corresponding to mag]
    decimal adjustedSize = (decimal)value / (1L << (mag * 10));

    // make adjustment when the value is large enough that
    // it would round up to 1000 or more
    if (Math.Round(adjustedSize, decimalPlaces) >= 1000)
    {
        mag += 1;
        adjustedSize /= 1024;
    }

    return string.Format("{0:n" + decimalPlaces + "} {1}", 
        adjustedSize, 
        SizeSuffixes[mag]);
}

And here's the original implementation I suggested, which may be marginally slower, but a bit easier to follow:

static readonly string[] SizeSuffixes = 
                  { "bytes", "KB", "MB", "GB", "TB", "PB", "EB", "ZB", "YB" };

static string SizeSuffix(Int64 value, int decimalPlaces = 1)
{
    if (value < 0) { return "-" + SizeSuffix(-value, decimalPlaces); } 

    int i = 0;
    decimal dValue = (decimal)value;
    while (Math.Round(dValue, decimalPlaces) >= 1000)
    {
        dValue /= 1024;
        i++;
    }

    return string.Format("{0:n" + decimalPlaces + "} {1}", dValue, SizeSuffixes[i]);
}

Console.WriteLine(SizeSuffix(100005000L));

One thing to bear in mind - in SI notation, "kilo" usually uses a lowercase k while all of the larger units use a capital letter. Windows uses KB, MB, GB, so I have used KB above, but you may consider kB instead.

OpenIso8583Net field 95 conversion to human readable format?

Turns out DE 95 is represented as 9999999999.99.
So getting a substring of 12 on the returned value i.e.000000040000000000000000000000000000000000 resolves the issue.

Substring of 12 would be 0000000400.00 which is $400.00

How can I convert bytes available to bytes available in KB, MB, GB etc?

I have found a very Informative Blog Regarding this :

https://askgif.com/blog/143/how-to-convert-given-bytes-in-kb-mb-gb-etc/ (Courtesy: https://askgif.com/)

if you are calculating total bytes then you can use the following function to find out the respective total bytes in KB, MB, GB, TB etc.

static String BytesToString(long byteCount)
    {
        string[] suf = { "B", "KB", "MB", "GB", "TB", "PB", "EB" }; //Longs run out around EB
        if (byteCount == 0)
            return "0" + suf[0];
        long bytes = Math.Abs(byteCount);
        int place = Convert.ToInt32(Math.Floor(Math.Log(bytes, 1024)));
        double num = Math.Round(bytes / Math.Pow(1024, place), 1);
        return (Math.Sign(byteCount) * num).ToString() + suf[place];
    }

Hope this will help you.

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