File size

File size
You are encouraged to solve this task according to the task description, using any language you may know.

In this task, the job is to verify the size of a file called "input.txt" for a file in the current working directory and another one in the file system root.

Ada

with Ada.Directories;  use Ada.Directories;
with Ada.Text_IO;      use Ada.Text_IO;
 
procedure Test_File_Size is
begin
   Put_Line (File_Size'Image (Size ("input.txt")) & " bytes");
   Put_Line (File_Size'Image (Size ("/input.txt")) & " bytes");
end Test_File_Size;

Note that reference to the root directory, if there is any, is OS specific.

ALGOL 68

There is no build in way to find the size of an arbitrary file, especially of the file is a special channel, e.g. a tape device.

Conceptually the procedure

PROC set = (REF FILE file,  INT page, line, character)VOID: ~ 

could be used to do a binary search find the last page's page number. And if it is known that every page has the same number of lines, and every line has the same number of char[s], and the character set is not compressible, then the size could be quickly calculated. Otherwise every page, and every line would have to be tallied.

It is probably much easier to use some an operating system library. This library is not part of the standard ALGOL 68 language definition.

AutoHotkey

FileGetSize, FileSize, input.txt  ; Retrieve the size in bytes.
MsgBox, Size of input.txt is %FileSize% bytes
FileGetSize, FileSize, \input.txt, K  ; Retrieve the size in Kbytes.
MsgBox, Size of \input.txt is %FileSize% Kbytes

BBC BASIC

      file% = OPENIN(@dir$+"input.txt")
      IF file% THEN
        PRINT "File size = " ; EXT#file%
        CLOSE #file%
      ENDIF
 
      file% = OPENIN("\input.txt")
      IF file% THEN
        PRINT "File size = " ; EXT#file%
        CLOSE #file%
      ENDIF

Bracmat

This solution assumes that the file can be opened for reading. The fil function is the Bracmat interface to the underlying C functions fopen, fclose, fseek, ftell, fread, fgetc, fwrite, fputc and feof. More than one file can be opened at the same time. Focus is shifted from one open file to another by mentioning the file name as the first argument.

(getFileSize=
  size
.     fil$(!arg,rb)     {read in binary mode}
    & fil$(,END)        {seek to end of file}
    & fil$(,TEL):?size  {tell where we are}
    & fil$(,SET,-1)     {seeking to an impossible position closes the file, and fails}
  | !size               {return the size}
);
 
getFileSize$"valid.bra"
113622
 
getFileSize$"c:\\boot.ini"
211
 

C

#include <stdlib.h>
#include <stdio.h>
 
long getFileSize(const char *filename)
{
  long result;
  FILE *fh = fopen(filename, "rb");
  fseek(fh, 0, SEEK_END);
  result = ftell(fh);
  fclose(fh);
  return result;
}
 
int main(void)
{
  printf("%ld\n", getFileSize("input.txt"));
  printf("%ld\n", getFileSize("/input.txt"));
  return 0;
}

Works with: POSIX

#include <stdlib.h>
#include <stdio.h>
#include <sys/stat.h>
 
int main(void)
{
  struct stat foo;
  stat("input.txt", &foo);
  printf("%ld\n", foo.st_size);
  stat("/input.txt", &foo);
  printf("%ld\n", foo.st_size);
  return 0;
}

C++

#include <iostream>
#include <fstream>
 
std::ios::off_type getFileSize(const char *filename) {
  std::ifstream f(filename);
  std::ios::pos_type begin = f.tellg();
  f.seekg(0, std::ios::end);
  std::ios::pos_type end = f.tellg();
  return end - begin;
}
 
int main() {
  std::cout << getFileSize("input.txt") << std::endl;
  std::cout << getFileSize("/input.txt") << std::endl;
  return 0;
}

C#

using System;
using System.IO;
 
class Program
{
    static void Main(string[] args)
    {
        Console.WriteLine(new FileInfo("/input.txt").Length);
        Console.WriteLine(new FileInfo("input.txt").Length);
    }
}
 

Clean

There is not function to get the file size, therefore we seek to the end and query the file pointer position.

import StdEnv
 
fileSize fileName world
    # (ok, file, world) = fopen fileName FReadData world
    | not ok = abort "Cannot open file"
    # (ok, file) = fseek file 0 FSeekEnd
    | not ok = abort "Cannot seek file"
    # (size, file) = fposition file
      (_, world) = fclose file world
    = (size, world)
 
Start world = fileSize "input.txt" world

Clojure

(import '[java.io File])
(defn show-size [filename]
  (println filename "size:" (.length (File. filename))))
 
(show-size "input.txt")
(show-size "/input.txt")

ColdFusion

<cfscript>
  localFile = getFileInfo(expandpath("input.txt"));
  rootFile = getFileInfo("/input.txt");
</cfscript>
 
<cfoutput>
  Size of input.txt is #localFile.size# bytes.
  Size of /input.txt is #rootFile.size# bytes.
</cfoutput>

Common Lisp

(with-open-file (stream (make-pathname :name "input.txt")
                 :direction :input
                 :if-does-not-exist nil)
  (print (if stream (file-length stream) 0)))
 
(with-open-file (stream (make-pathname :directory '(:absolute "") :name "input.txt")
                 :direction :input
                 :if-does-not-exist nil)
  (print (if stream (file-length stream) 0)))

D

To gets the size of a single file:

import std.file;
 
void main() {
    auto len = getSize("data.txt");
}

Alternative ways to get file sizes:

import std.stdio, std.path, std.file, std.stream;
// NB: mmfile can treat the file as an array in memory
import std.mmfile;
 
string[] generateTwoNames(string name) {
    string cwd  = curdir ~ sep; // on current directory
    string root = sep;          // on root
 
    // remove path, left only basename
    name = std.path.getBaseName(name);
 
    // NB: in D ver.2, getBaseName is alias of basename
    return [cwd ~ name, root ~ name];
}
 
void testsize(string fileName1) {
    foreach (fileName2; generateTwoNames(fileName1)) {
        try {
            writefln("File %s has size:", fileName2);
            writefln("%10d bytes by std.file.getSize (function),",
                     std.file.getSize(fileName2));
            writefln("%10d bytes by std.stream (class),",
                     (new std.stream.File(fileName2)).size);
            writefln("%10d bytes by std.mmfile (class).",
                     (new std.mmfile.MmFile(fileName2)).length);
        } catch (Exception e) {
            writefln(e.msg);
        }
        writeln();
    }
}
 
void main() {
    testsize(r"input.txt");
}

One output:

File .\input.txt has size:
    749596 bytes by std.file.getSize (function),
    749596 bytes by std.stream (class),
    749596 bytes by std.mmfile (class).

File \input.txt has size:
    471964 bytes by std.file.getSize (function),
    471964 bytes by std.stream (class),
    471964 bytes by std.mmfile (class).

Delphi

program SizeOfFile;
 
{$APPTYPE CONSOLE}
 
uses SysUtils;
 
function CheckFileSize(const aFilename: string): Integer;
var
  lFile: file of Byte;
begin
  AssignFile(lFile, aFilename);
  FileMode := 0; {Access file in read only mode}
  Reset(lFile);
  Result := FileSize(lFile);
  CloseFile(lFile);
end;
 
begin
  Writeln('input.txt ', CheckFileSize('input.txt'));
  Writeln('\input.txt ', CheckFileSize('\input.txt'));
end.

E

for file in [<file:input.txt>, <file:///input.txt>] {
  println(`The size of $file is ${file.length()} bytes.`)
}

Erlang

-module(file_size).
-export([file_size/0]).
 
-include_lib("kernel/include/file.hrl").
 
file_size() ->
    print_file_size("input.txt"),
    print_file_size("/input.txt").
 
print_file_size(Filename) ->
    case file:read_file_info(Filename) of
	{ok, FileInfo} ->
	    io:format("~s ~p~n", [Filename, FileInfo#file_info.size]);
	{error, _} ->
	    io:format("~s could not be opened~n",[Filename])
    end.
 

Euphoria

include file.e
 
function file_size(sequence file_name)
    object x
    x = dir(file_name)
    if sequence(x) and length(x) = 1 then
        return x[1][D_SIZE]
    else
        return -1 -- the file does not exist
    end if
end function
 
procedure test(sequence file_name)
    integer size
    size = file_size(file_name)
    if size < 0 then
        printf(1,"%s file does not exist.\n",{file_name})
    else
        printf(1,"%s size is %d.\n",{file_name,size})
    end if
end procedure
 
test("input.txt") -- in the current working directory
test("/input.txt") -- in the file system root

Factor

"input.txt" file-info size>> .
    1321
"file-does-not-exist.txt" file-info size>>
 "Unix system call ``stat'' failed:"...

Forth

: .filesize ( addr len -- ) 2dup type ."  is "
  r/o open-file throw
  dup file-size throw  <# #s #> type ."  bytes long." cr
  close-file throw ;
 
 s" input.txt" .filesize
s" /input.txt" .filesize

Go

package main
 
import "fmt"
import "os"
 
func printFileSize(f string) {
    if stat, err := os.Stat(f); err != nil {
        fmt.Println(err)
    } else {
        fmt.Println(stat.Size())
    }
}
 
func main() {
    printFileSize("input.txt")
    printFileSize("/input.txt")
}

Groovy

println new File('index.txt').length();
println new File('/index.txt').length();

Haskell

import System.IO
 
printFileSize filename = withFile filename ReadMode hFileSize >>= print
 
main = mapM_ printFileSize ["input.txt", "/input.txt"]

or

import System.Posix.File
 
printFileSize filename = do stat <- getFileStatus filename
                            print (fileSize stat)
 
main = mapM_ printFileSize ["input.txt", "/input.txt"]

HicEst

READ(FILE="input.txt", LENgth=bytes) ! bytes = -1 if not existent
READ(FILE="C:\input.txt", LENgth=bytes) ! bytes = -1 if not existent 

Icon and Unicon

Icon doesn't support 'stat'; however, information can be obtained by use of the system function to access command line.

every dir := !["./","/"] do {
   write("Size of ",f := dir || "input.txt"," = ",stat(f).size)  |stop("failure for to stat ",f) 
   }

Note: Icon and Unicon accept both / and \ for directory separators.

J

require 'files'
fsize 'input.txt';'/input.txt'

Java

import java.io.File;
 
public class FileSize
{
    public static void main ( String[] args )
    {
        System.out.println("input.txt  : " + new File("input.txt").length() + " bytes");
        System.out.println("/input.txt : " + new File("/input.txt").length() + " bytes");
    }
}
 

JavaScript

Works with: JScript

var fso = new ActiveXObject("Scripting.FileSystemObject");
fso.GetFile('input.txt').Size;
fso.GetFile('c:/input.txt').Size;

K

_size "input.txt"
_size "/input.txt"

Liberty BASIC

'input.txt in current directory
OPEN DefaultDir$ + "/input.txt" FOR input AS #m
PRINT "File size: "; lof(#m)
CLOSE #m
 
'input.txt in root
OPEN "c:/input.txt" FOR input AS #m
PRINT "File size: "; lof(#m)
CLOSE #m

Lua

function GetFileSize( filename )
    local fp = io.open( filename )
    if fp == nil then 
 	return nil 
    end
    local filesize = fp:seek( "end" )
    fp:close()
    return filesize
end

Mathematica

 
FileByteCount["input.txt"]
FileByteCount[FileNameJoin[{$RootDirectory, "input.txt"}]]

MATLAB / Octave

d1 = dir('input.txt');
d2 = dir('/input.txt');
fprintf('Size of input.txt is %d bytes\n', d1.bytes)
fprintf('Size of /input.txt is %d bytes\n', d2.bytes)

MAXScript

-- Returns filesize in bytes or 0 if the file is missing
getFileSize "index.txt"
getFileSize "\index.txt"

Mirah

import java.io.File
 
puts File.new('file-size.mirah').length()
puts File.new("./#{File.separator}file-size.mirah").length()

Modula-3

MODULE FSize EXPORTS Main;
 
IMPORT IO, Fmt, FS, File, OSError;
 
VAR fstat: File.Status;
 
BEGIN
  TRY
    fstat := FS.Status("input.txt");
    IO.Put("Size of input.txt: " & Fmt.LongInt(fstat.size) & "\n");
    fstat := FS.Status("/input.txt");
    IO.Put("Size of /input.txt: " & Fmt.LongInt(fstat.size) & "\n");
  EXCEPT
  | OSError.E => IO.Put("ERROR: Could not get file status.\n");
  END;
END FSize.

Objective-C

NSFileManager *fm = [NSFileManager defaultManager];
 
// Pre-OS X 10.5
NSLog(@"%llu", [[fm fileAttributesAtPath:@"input.txt" traverseLink:YES] fileSize]);
 
// OS X 10.5+
NSLog(@"%llu", [[fm attributesOfItemAtPath:@"input.txt" error:NULL] fileSize]);

Objeck

 
use IO;
...
File("input.txt")->Size()->PrintLine();
File("c:\input.txt")->Size()->PrintLine();
 

OCaml

let printFileSize filename =
  let ic = open_in filename in
  Printf.printf "%d\n" (in_channel_length ic);
  close_in ic ;;
 
printFileSize "input.txt" ;;
printFileSize "/input.txt" ;;

For files greater than Pervasives.max_int, one can use the module Unix.LargeFile:

let printLargeFileSize filename =
  let ic = open_in filename in
  Printf.printf "%Ld\n" (LargeFile.in_channel_length ic);
  close_in ic ;;

Alternatively:

#load "unix.cma" ;;
open Unix ;;
Printf.printf "%d\n" (stat "input.txt").st_size ;;
Printf.printf "%d\n" (stat "/input.txt").st_size ;;

Oz

declare
  [Path] = {Module.link ['x-oz://system/os/Path.ozf']}
in
  {Show {Path.size "input.txt"}}
  {Show {Path.size "/input.txt"}}

Pascal

See Delphi

Perl

use File::Spec::Functions qw(catfile rootdir);
print -s 'input.txt';
print -s catfile rootdir, 'input.txt';

Perl 6

say 'input.txt'.IO.s;
say '/input.txt'.IO.s;

PHP

<?php
echo filesize('input.txt'), "\n";
echo filesize('/input.txt'), "\n";
?>

PicoLisp

(println (car (info "input.txt")))
(println (car (info "/input.txt")))

Pike

import Stdio;
 
int main(){
   write(file_size("input.txt") + "\n");
   write(file_size("/input.txt") + "\n");
}

Pop11

;;; prints file size in bytes
sysfilesize('input.txt') =>
sysfilesize('/input.txt') =>

PostScript

status returns status information about a file if given a file name. This includes the size in pages (implementation-dependent), the size in bytes, creation and modification time and a final true. The values not needed here are simply poped off the stack.

(input.txt  ) print
(input.txt) status pop pop pop = pop
(/input.txt ) print
(/input.txt) status pop pop pop = pop

PowerShell

Get-ChildItem input.txt | Select-Object Name,Length
Get-ChildItem \input.txt | Select-Object Name,Length

PureBasic

Debug FileSize("input.txt")
Debug FileSize("/input.txt")

Python

import os
 
size = os.path.getsize('input.txt')
size = os.path.getsize('/input.txt')

R

Works with: R version 2.8.1

R has a function file.info() in the base package that performs this function. Note that regardless of the OS, R uses forward slashes for the directories.

sizeinwd <- file.info('input.txt')[["size"]]
sizeinroot <- file.info('/input.txt')[["size"]]

REBOL

size? %info.txt
size? %/info.txt
size? ftp://username:password@ftp.site.com/info.txt
size? http://rosettacode.org

RapidQ

File I/O is one of the things where RapidQ differs from standard Basic. RapidQ uses file streams.

Method 1: display file size using file streams

$INCLUDE "rapidq.inc"
 
DIM file AS QFileStream
 
FUNCTION fileSize(name$) AS Integer
    file.Open(name$, fmOpenRead)
    Result = file.Size
    file.Close
END FUNCTION
 
PRINT "Size of input.txt is "; fileSize("input.txt")
PRINT "Size of \input.txt is "; fileSize("\input.txt")

Method 2: using DIR$

FileName$ = DIR$("input.txt", 0)
PRINT "Size of input.txt is "; FileRec.Size
FileName$ = DIR$("\input.txt", 0)
PRINT "Size of \input.txt is "; FileRec.Size

Raven

'input.txt'  status.size
'/input.txt' status.size

Retro

The simple way is to open and read the size. This may crash if the file does not exist.

with files'
"input.txt" :R open &size sip close drop putn
"/input.txt" :R open &size sip close drop putn

For added stability, check that the returned file handle is not zero:

with files'
"input.txt" :R open over 0 <> [ &size sip close drop ] ifTrue

Or, if you need to do this more often, setup a function that'll also display an error message if the file does not exist:

with files'
: getFileSize ( $-n )
  :R open 0 over =
  [ "File does Not Exist\n" puts ]
  [ &size sip close drop ] if ;
 
"input.txt" getFileSize putn
"/input.txt" getFileSize putn

Ruby

size = File.size('input.txt')
size = File.size('/input.txt')

Run BASIC

print fileSize(DefaultDir$,"input.txt")  ' current default directory
print fileSize("","input.txt")       ' root directory
 
function fileSize(dir$,file$)
open dir$;"\";file$ FOR input as #f
fileSize = lof(#f)                   ' Length Of File
close #f
end function

Scheme

 
(define (file-size filename)
  (call-with-input-file filename (lambda (port)
    (let loop ((c (read-char port))
               (count 0))
      (if (eof-object? c) 
          count
          (loop (read-char port) (+ 1 count)))))))
 
(file-size "input.txt")
(file-size "/input.txt")
 

Seed7

$ include "seed7_05.s7i";
 
const proc: main is func
  begin
    writeln(fileSize("input.txt"));
    writeln(fileSize("/input.txt"));
  end func;

Slate

(File newNamed: 'input.txt') fileInfo fileSize.
(File newNamed: '/input.txt') fileInfo fileSize.

Smalltalk

(File name: 'input.txt') size printNl.
(File name: '/input.txt') size printNl.

Standard ML

val size = OS.FileSys.fileSize "input.txt" ;;
val size = OS.FileSys.fileSize "/input.txt" ;

Tcl

file size input.txt
file size /input.txt

Toka

A trivial method follows:

" input.txt"  "R" file.open dup file.size . file.close
" /input.txt" "R" file.open dup file.size . file.close

A better method would be to define a new function that actually checks whether the file exists:

[ "R" file.open
  dup 0 <> [ dup file.size . file.close ] ifTrue
  drop
] is display-size
 
" input.txt"  display-size
" /input.txt" display-size

TUSCRIPT

 
$$ MODE TUSCRIPT
-- size of file input.txt
file="input.txt"
ERROR/STOP OPEN (file,READ,-std-)
file_size=BYTES ("input.txt")
ERROR/STOP CLOSE (file)
 
-- size of file x:/input.txt
ERROR/STOP OPEN (file,READ,x)
file_size=BYTES (file)
ERROR/STOP CLOSE (file)
 

UNIX Shell

An interactive user would run ls -l input.txt /input.txt to see the file sizes. This task is more difficult for a shell script, that must extract each size from command output.

Using ls

ls most likely gets the length from the file's inode.

size1=$(ls -l input.txt | tr -s ' ' | cut -d ' ' -f 5)
size2=$(ls -l /input.txt | tr -s ' ' | cut -d ' ' -f 5)

ls -l reports the size in 5th field, with spaces between fields. tr squeezes spaces (because cut needs one single space between fields), and cut extracts 5th field.

Using wc

wc may actually read the whole file and count the bytes. Some implementations, like wc.c from GNU coreutils, can optimize wc -c by getting the length from the file's inode.

size1=$(wc -c < input.txt | tr -d ' ')
size2=$(wc -c < /input.txt | tr -d ' ')

The peculiar use of wc -c < file, not wc -c file, is to prevent printing the file's name. Then wc only reports the size. Some versions of wc print spaces before the number; tr deletes all these spaces.

Using BSD stat

BSD has stat(1), a nonstandard command. With stat, a shell script can easily get the file size.

Works with: NetBSD version 1.6

Works with: FreeBSD version 4.10

Works with: OpenBSD version 3.8

size1=$(stat -f %z input.txt)
size2=$(stat -f %z /input.txt)

Z Shell

Works with: zsh

# from module 'zsh/stat', load builtin 'zstat'
zmodload -F zsh/stat b:zstat
 
size1=$(zstat +size input.txt)
size2=$(zstat +size /input.txt)

Vedit macro language

Num_Type(File_Size("input.txt"))
Num_Type(File_Size("/input.txt"))

Visual Basic .NET

Platform: .NET

Works with: Visual Basic .NET version 9.0+

Dim local As New IO.FileInfo("input.txt")
Console.WriteLine(local.Length)
 
Dim root As New IO.FileInfo("\input.txt")
Console.WriteLine(root.Length)