CloudFlare has suffered a massive security issue affecting all of its customers, including Rosetta Code. I will be expiring all passwords and session cookies sometime Friday, February 24th. Cookie longevity will also be reduced for 30 days. --Michael Mol (talk) 04:56, 24 February 2017 (UTC)

File size distribution

From Rosetta Code
File size distribution is a draft programming task. It is not yet considered ready to be promoted as a complete task, for reasons that should be found in its talk page.
File Size Distribution

Beginning from the current directory, or optionally from a directory specified as a command-line argument, determine how many files there are of various sizes in a directory hierarchy. My suggestion is to sort by logarithmn of file size, since a few bytes here or there, or even a factor of two or three, may not be that significant. Don't forget that empty files may exist, to serve as a marker. Is your file system predominantly devoted to a large number of smaller files, or a smaller number of huge files?


The distribution is stored in a collections.Counter object (like a dictionary with automatic 0 value when a key is not found, useful when incrementing). Anything could be done with this object, here the number of files is printed for increasing sizes. No check is made during the directory walk: usually, safeguards would be needed or the program will fail on any unreadable file or directory (depending on rights, or too deep paths, for instance). Here links are skipped, so it should avoid cycles.

import sys, os
from collections import Counter
def dodir(path):
global h
for name in os.listdir(path):
p = os.path.join(path, name)
if os.path.islink(p):
elif os.path.isfile(p):
h[os.stat(p).st_size] += 1
elif os.path.isdir(p):
def main(arg):
global h
h = Counter()
for dir in arg:
s = n = 0
for k, v in sorted(h.items()):
print("Size %d -> %d file(s)" % (k, v))
n += v
s += k * v
print("Total %d bytes for %d files" % (s, n))


#lang racket
(define (file-size-distribution (d (current-directory)) #:size-group-function (sgf values))
(for/fold ((rv (hash)) (Σ 0) (n 0)) ((f (in-directory d)) #:when (file-exists? f))
(define sz (file-size f))
(values (hash-update rv (sgf sz) add1 0) (+ Σ sz) (add1 n))))
(define (log10-or-so x) (if (zero? x) #f (round (/ (log x) (log 10)))))
(define number-maybe-<
(match-lambda** [(#f #f) #f]
[(#f _) #t]
[(_ #f) #f]
[(a b) (< a b)]))
(define ...s? (match-lambda** [(one 1) one] [(one n) (string-append one "s")]))
(define ((report-fsd f) fsd Σ n)
(for/list ((k (in-list (sort (hash-keys fsd) number-maybe-<))))
(printf "~a(size): ~a -> ~a ~a~%"
(object-name f)
(hash-ref fsd k) (...s? "file" (hash-ref fsd k))))
(printf "Total: ~a ~a in ~a ~a~%" Σ (...s? "byte" Σ) n (...s? "file" n)))
(module+ test
(call-with-values (λ () (file-size-distribution #:size-group-function log10-or-so))
(report-fsd log10-or-so)))
log10-or-so(size): #f -> 3 files
log10-or-so(size): 0 -> 4 files
log10-or-so(size): 1.0 -> 39 files
log10-or-so(size): 2.0 -> 57 files
log10-or-so(size): 3.0 -> 406 files
log10-or-so(size): 4.0 -> 198 files
log10-or-so(size): 5.0 -> 20 files
log10-or-so(size): 6.0 -> 6 files
Total: 10210127 bytes in 733 files


// hoover all files in tree, don't return directories
fcn(pipe,dir){ File.globular(dir,"*",True,8,pipe); }
.launch(pipe,vm.arglist[0]); // thread
foreach fnm in (pipe){
sz,szd:=File.len(fnm), sz.numDigits;
N+=1; SZ+=sz; maxd=maxd.max(szd);
println("Found %d files, %,d bytes, %,d mean.".fmt(N,SZ,SZ/N));
szchrs,idx,comma:=",nnn"*20, -1, Walker.cycle(0,0,1).next;
println("%15s  %s (* = %.2f)".fmt("File size","Number of files",1.0/scale));
foreach sz,cnt in ([0..].zip(dist[0,maxd])){
println("%15s : %s".fmt(szchrs[idx,*], "*"*(scale*cnt).round().toInt()));
idx-=1 + comma();
$ zkl flSzDist.zkl ..
Found 1832 files, 108,667,806 bytes, 59,316 mean.
      File size   Number of files (* = 13.44)
              n : *
             nn : ***
            nnn : ********
          n,nnn : **********************************
         nn,nnn : **************************************************
        nnn,nnn : ********************************
      n,nnn,nnn : *******

$ zkl flSzDist.zkl /media/Tunes/
Found 4320 files, 67,627,849,052 bytes, 15,654,594 mean.
      File size   Number of files (* = 69.84)
              n : 
             nn : 
            nnn : 
          n,nnn : *
         nn,nnn : 
        nnn,nnn : 
      n,nnn,nnn : *
     nn,nnn,nnn : **************************************************
    nnn,nnn,nnn : ********
  n,nnn,nnn,nnn : *