# Letter frequency

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

Open a text file and count the occurrences of each letter.

Some of these programs count all characters (including punctuation), but some only count letters A to Z.

## ACL2

`(defun increment-alist (tbl key)   (cond ((endp tbl) (list (cons key 1)))         ((eql (car (first tbl)) key)          (cons (cons key (1+ (cdr (first tbl))))                (rest tbl)))         (t (cons (first tbl)                  (increment-alist (rest tbl) key))))) (defun freq-table (xs)   (if (endp xs)       nil       (increment-alist (freq-table (rest xs))                        (first xs)))) (defun letter-freq (str)   (freq-table (coerce str 'list)))`

`with Ada.Text_IO; procedure Letter_Frequency is   Counters: array (Character) of Natural := (others => 0); -- initialize all Counters to 0   C:        Character;   File:     Ada.Text_IO.File_Type; begin   Ada.Text_IO.Open(File, Mode => Ada.Text_IO.In_File, Name => "letter_frequency.adb");   while not Ada.Text_IO.End_Of_File(File) loop      Ada.Text_IO.Get(File, C);      Counters(C) := Counters(C) + 1;   end loop;    for I in Counters'Range loop      if Counters(I) > 0 then            Ada.Text_IO.Put_Line("'" & I & "':" & Integer'Image(Counters(I)));      end if;   end loop;end Letter_Frequency;`
Output:
(counting the characters of its own source code):
```>./letter_frequency
' ': 122
'"': 6
'&': 3

... [a lot of lines omitted]

'x': 7
'y': 5
'z': 1```

## Aikido

`import ctype var letters = new int [26] var s = openin (args[0])while (!s.eof()) {    var ch = s.getchar()    if (s.eof()) {        break    }    if (ctype.isalpha (ch)) {        var n = cast<int>(ctype.tolower(ch) - 'a')        ++letters[n]    }} foreach i letters.size() {    println (cast<char>('a' + i) + " " + letters[i])}`

## Aime

Letters proper:

`file f;index x;integer c; f.affix("unixdict.txt"); while ((c = f.pick) ^ -1) {    x[c] += 1;} c = 'A';while (c <= 'Z') {    o_form("%c: /w5/\n", c, x[c] += x[c + 'a' - 'A'] += 0);    c += 1;}`

All chars:

`file f;index x;integer c, n; f.affix("unixdict.txt"); while ((c = f.pick) ^ -1) {    x[c] += 1;} for (c, n in x) {    o_form("%c: /w5/\n", c, n);}`

## ALGOL 68

` BEGIN   [0:max abs char]INT histogram;   FOR i FROM 0 TO max abs char DO histogram[i] := 0 OD;   FILE input file;   STRING input file name = "Letter_frequency.a68";   IF open (input file, input file name, stand in channel) /= 0 THEN      put (stand error, ("Cannot open ", input file name, newline));      stop   ELSE      on file end (input file, (REF FILE f) BOOL: (close (f); GOTO finished))   FI;   DO      STRING s;      get (input file, (s, newline));      FOR i TO UPB s DO	 CHAR c = s[i];	 IF "A" <= c AND c <= "Z" OR "a" <= c AND c <= "z" THEN	    histogram[ABS c] PLUSAB 1	 FI     OD   OD;   close (input file);finished:   FOR i FROM ABS "A" TO ABS "Z" DO printf ((\$a3xg(0)l\$, REPR i, histogram[i])) OD;   FOR i FROM ABS "a" TO ABS "z" DO printf ((\$a3xg(0)l\$, REPR i, histogram[i])) ODEND `
Output:
Counting letters in its own source code:
```A   11
B   9
C   2
D   13
E   11
F   14
G   4
H   3
I   10
J   0
[[ Omitted for K – Z and a – p ]]
q   1
r   15
s   19
t   24
u   10
v   0
w   3
x   4
y   1
z   2
```

## APL

`       freq←{(⍪∪⍵),+/(∪⍵)∘.⍷⍵}       freq 0 1 2 3 2 3 4 3 4 4 40 11 12 23 34 4                     freq 'balloon'b 1a 1l 2o 2n 1 `

## AutoHotkey

`OpenFile = %A_ScriptFullPath% ; use own source codeFileRead, FileText, %OpenFile%Loop 26{	StringReplace, junk, FileText, % Chr(96+A_Index),, UseErrorLevel	out .= Chr(96+A_Index) ": " ErrorLevel "`n"}MsgBox % out`
Output:
(using script's own file):
```a: 6
b: 1
c: 6
d: 4
e: 24
[several lines omitted]
x: 5
y: 0
z: 0```

## AutoIt

This function prints the Letter frequency of a given textfile. You can choose to use case sensitive search and if special chars should be searched too.

` Func _Letter_frequency(\$Path, \$fcase = True, \$fspecial_chars = True)	Local \$hFile, \$sRead, \$iupto, \$iStart, \$iCount	If Not \$fcase Then \$fcase = False	If Not \$fspecial_chars Then		\$iStart = 64		If Not \$fcase Then			\$iupto = 26		Else			\$iupto = 58		EndIf	Else		\$iStart = 31		\$iupto = 224	EndIf	\$hFile = FileOpen(\$Path, 0)	\$sRead = FileRead(\$hFile)	FileClose(\$hFile)	For \$i = 1 To \$iupto		If Not \$fspecial_chars Then			If \$iStart + \$i > 90 And \$iStart + \$i < 97 Then ContinueLoop		EndIf		\$sRead = StringReplace(\$sRead, Chr(\$iStart + \$i), "", 0, \$fcase)		\$iCount = @extended		If \$iCount > 0 Then ConsoleWrite(Chr(\$iStart + \$i) & " : " & \$iCount & @CRLF)	NextEndFunc   ;==>_Letter_frequency`
Output:
```A : 32
B : 2
C : 15
E : 31
F : 10
[several lines omitted]
u : 14
v : 1
w : 1
x : 14```

## AWK

` # usage: awk -f letters.awk HolyBible.txt BEGIN { FS="" }      { for(i=1;i<=NF;i++) m[\$i]++}END   { for(i in m) printf("%9d %-14s\n", m[i],i) } `

## BaCon

`txt\$ = LOAD\$("bible.txt") FOR x = 97 TO 122    PRINT CHR\$(x-32), " ", CHR\$(x), " : ", COUNT(txt\$, x-32), " - ", COUNT(txt\$, x)NEXT `
Output:
```A a : 17915 - 257815
B b : 4714 - 44161
C c : 1698 - 53373
D d : 8782 - 149313
E e : 2710 - 409525
F f : 2386 - 81157
G g : 6206 - 49096
H h : 3208 - 279471
I i : 13302 - 180660
J j : 6374 - 2515
K k : 547 - 21745
L l : 9222 - 120716
M m : 3056 - 76884
N n : 1891 - 223166
O o : 8896 - 234290
P p : 1877 - 41377
Q q : 6 - 958
R r : 7568 - 162761
S s : 4906 - 185124
T t : 7763 - 309983
U u : 333 - 83140
V v : 107 - 30258
W w : 2408 - 63079
X x : 2 - 1476
Y y : 569 - 58007
Z z : 904 - 2068
```

## BBC BASIC

`      DIM cnt%(255)       file% = OPENIN("C:\unixdict.txt")      IF file%=0 ERROR 100, "Could not open file"       REPEAT        A\$ = GET\$#file%        L% = LEN(A\$)        IF L% THEN          FOR I% = 1 TO L%            cnt%(ASCMID\$(A\$,I%)) += 1          NEXT        ENDIF      UNTIL EOF#file%      CLOSE #file%       FOR c% = &41 TO &5A        PRINT CHR\$(c%)CHR\$(c%+32) ": " cnt%(c%)+cnt%(c%+32)      NEXT`
Output:
```Aa:      16421
Bb:       4115
Cc:       8216
Dd:       5799
Ee:      20144
Ff:       2662
Gg:       4129
Hh:       5208
Ii:      13980
Jj:        430
Kk:       1925
Ll:      10061
Mm:       5828
Nn:      12097
Oo:      12738
Pp:       5516
Qq:        378
Rr:      13436
Ss:      10210
Tt:      12836
Uu:       6489
Vv:       1902
Ww:       1968
Xx:        617
Yy:       3633
Zz:        433
```

## Bracmat

`(lc=  counts c.     fil\$(!arg,r)                        {open file for reading}    & 0:?counts    &   whl      ' ( fil\$:?c                         {read a byte}        &     ( !c:(~<A:~>Z|~<a:~>z)              | 0              )            + !counts          : ?counts                       {simply add any found letter to the sum}        )    & fil\$(,SET,-1)                       {close the file by seeking to impossible file position.}  | !counts                               {return the sum}); lc\$"valid.bra"                            {example: count letters in Bracmat's validation suite.} `
`107*A+ 33*B+ 37*C+ 39*D+ 74*E+ 50*F+ 27*G+ 28*H+ 20*I+ 55*J+ 32*K+ 112*L+ 36*M+ 32*N+ 621*O+ 43*P+ 25*R+ 67*S+ 62*T+ 64*U+ 5*V+ 26*W+ 353*X+ 248*Y+ 70*Z+ 2173*a+ 840*b+ 738*c+ 639*d+ 1345*e+ 472*f+ 372*g+ 568*h+ 91*j+ 142*k+ 529*l+ 409*m+ 941*n+ 840*o+ 336*p+ 65*q+ 993*r+ 1018*s+ 2097*t+ 978*u+ 122*v+ 156*w+ 909*x+ 685*y+ 211*z+ 1035*i`

## C

`/* declare array */int frequency[26];int ch;FILE* txt_file = fopen ("a_text_file.txt", "rt"); /* init the freq table: */for (ch = 0; ch < 26; ch++)    frequency[ch] = 0; while (1) {    ch = fgetc(txt_file);    if (ch == EOF) break; /* end of file or read error.  EOF is typically -1 */     /* assuming ASCII; "letters" means "a to z" */    if ('a' <= ch && ch <= 'z')      /* lower case */        frequency[ch-'a']++;    else if ('A' <= ch && ch <= 'Z') /* upper case */        frequency[ch-'A']++;}`

## C#

`using System;using System.Collections.Generic;using System.IO;using System.Linq; class Program{    static SortedDictionary<TItem, int> GetFrequencies<TItem>(IEnumerable<TItem> items)    {        var dictionary = new SortedDictionary<TItem, int>();        foreach (var item in items)        {            if (dictionary.ContainsKey(item))            {                dictionary[item]++;            }            else            {                dictionary[item] = 1;            }        }        return dictionary;    }     static void Main(string[] arguments)    {        var file = arguments.FirstOrDefault();        if (File.Exists(file))        {            var text = File.ReadAllText(file);            foreach (var entry in GetFrequencies(text))            {                Console.WriteLine("{0}: {1}", entry.Key, entry.Value);            }        }    }}`
Output:
``` : 1
!: 1
,: 1
H: 1
d: 1
e: 1
l: 3
o: 2
r: 1
w: 1```

Declarative approach:

` var freq =  from c in str            where char.IsLetter(c)            orderby c            group c by c into g            select g.Key + ":" + g.Count(); foreach(var g in freq)    Console.WriteLine(g); `
```C:2
I:1
K:1
L:2
W:1
a:4
...
y:2
```

## C++

`#include <fstream>#include <iostream> int main(){	std::ifstream input("filename.txt", std::ios_base::binary);	if (!input)	{		std::cerr << "error: can't open file\n";		return -1;	} 	size_t count[256];	std::fill_n(count, 256, 0); 	for (char c; input.get(c); ++count[uint8_t(c)]) // process input file		; // empty loop body 	for (size_t i = 0; i < 256; ++i)	{		if (count[i] && isgraph(i)) // non-zero counts of printable characters		{			std::cout << char(i) << " = " << count[i] << '\n';		}	}}`
Output:
when file contains "Hello, world!" (without quotes):
```! = 1
, = 1
H = 1
d = 1
e = 1
l = 3
o = 2
r = 1
w = 1
```

## Common Lisp

`(defun letter-freq (file)  (with-open-file (stream file)    (let ((str (make-string (file-length stream)))	  (arr (make-array 256 :element-type 'integer :initial-element 0)))      (read-sequence str stream)      (loop for c across str do (incf (aref arr (char-code c))))      (loop for c from 32 to 126 for i from 1 do	    (format t "~c: ~d~a"		    (code-char c) (aref arr c)		    (if (zerop (rem i 8)) #\newline #\tab)))))) (letter-freq "test.lisp")`

## Clojure

`(println (sort-by second > 			(frequencies (map #(java.lang.Character/toUpperCase %)					  (filter #(java.lang.Character/isLetter %) (slurp "text.txt"))))))`

## Component Pascal

BlackBox Component Builder

` MODULE LetterFrecuency;IMPORT Files,StdLog,Strings; PROCEDURE Do*;VAR	loc: Files.Locator;	fd: Files.File;	rd: Files.Reader;	x: BYTE;	frecuency: ARRAY 26 OF LONGINT;	c: CHAR;	i: INTEGER;BEGIN	loc := Files.dir.This("BBTest/Mod");	fd := Files.dir.Old(loc,"LetterFrecuency.odc",FALSE);	rd := fd.NewReader(NIL); 	(* init the frecuency array *)	FOR i := 0 TO LEN(frecuency) - 1 DO frecuency[i] := 0 END; 	(* collect frecuencies *)	WHILE ~rd.eof DO		rd.ReadByte(x);c := CAP(CHR(x));		(* convert vowels with diacritics *)		CASE ORD(c) OF			 193: c := 'A';			|201: c := 'E';			|205: c := 'I';			|211: c := 'O';			|218: c := 'U';			ELSE		END;		IF (c >= 'A') & (c <= 'Z') THEN			INC(frecuency[ORD(c) - ORD('A')]);		END	END; 	(* show data *)	FOR i := 0 TO LEN(frecuency) - 1 DO		StdLog.Char(CHR(i + ORD('A')));StdLog.String(":> ");StdLog.Int(frecuency[i]);		StdLog.Ln	ENDEND Do;END LetterFrecuency. `

Execute: ^Q LetterFrecuency.Do

Output:
```A:>  28
B:>  7
C:>  100
D:>  94
E:>  168
F:>  30
G:>  10
H:>  11
I:>  49
J:>  0
K:>  1
L:>  67
M:>  25
N:>  57
O:>  81
P:>  3
Q:>  0
R:>  91
S:>  90
T:>  94
U:>  32
V:>  14
W:>  15
X:>  15
Y:>  17
Z:>  3
```

## D

`void main() {    import std.stdio, std.ascii, std.algorithm, std.range;     uint[26] frequency;     foreach (const buffer; "unixdict.txt".File.byChunk(2 ^^ 15))        foreach (immutable c; buffer.filter!isAlpha)            frequency[c.toLower - 'a']++;     writefln("%(%(%s, %),\n%)", frequency[].chunks(10));}`
Output:
```16421, 4115, 8216, 5799, 20144, 2662, 4129, 5208, 13980, 430,
1925, 10061, 5828, 12097, 12738, 5516, 378, 13436, 10210, 12836,
6489, 1902, 1968, 617, 3633, 433```

## EchoLisp

We use a property list - plist for short - which is a hash table, to store the pairs ( letter . count) .

` ;; bump count when letter added(define (hash-counter hash key )		;; (set! key (string-downcase key)) - if ignore case wanted		(putprop hash (1+ (or (getprop hash key) 0 )) key)) ;;  apply to exploded string;;  and sort result(define (hash-compare a b) ( < (first a) (first b)))(define (count-letters hash string)		(map (curry hash-counter hash) (string->list string))		(list-sort hash-compare (symbol-plist hash))) `
Output:
` (define (file-stats file string) 	(set-plist! 'file-stats null) ; reset counters	(writeln (count-letters 'file-stats string))	(writeln "Total letters:" (string-length string))	(writeln "Total lines:" (getprop 'file-stats "#\\newline"))) ; frequency for 'help.html' file(file->string file-stats) ; browser 'open' dialog ➛ help.html -> string➛ (( 28918) (! 138) (# 1035) (#\newline 4539) (#\tab 409) (\$ 7) (% 24) (& 136) (' 1643) ((3577) () 3583) (* 233) (+ 303) (, 599) (- 3164) (. 1454) (/ 5388) (0 1567) (1 1769) (2 1258) (3 857) (4 1872) (5 453) (6 581) (7 344)  (8 337) (9 411) (: 1235) (; 647) (< 9951) (= 1834) (> 10255) (? 392) (@ 11) (A 166) (B 92) (C 144) (D 72) (E 224) (F 52) (G 35) (H 42) (I 193) (J 31) (K 36) (L 196) (M 82) (N 94) (O 132) (P 192) (Q 27) (R 56) (S 220) (T 226) (U 37) (V 51) (W 28) (X 6) (Y 38) (Z 2) ([ 237) (\ 12) (] 215) (^ 28) (_ 107) (` 7) (a 8420) (b 4437) (c 3879) (d 4201)  (e 11905) (f 2989) (g 2068) (h 3856) (i 11313) (j 334) (k 653) (l 5748) (m 3048) (n 7020) (o 7207) (p 3585) (q 249) (r 8312) (s 8284) (t 8704) (u 3833) (v 1135) (w 861) (x 1172) (y 1451) (z 268) ({ 123) (| 62) (} 123) (~ 7) (§ 1) (© 1) (« 1) (» 1) (É 2) (à 18) (â 3) (ç 3) (è 6) (é 53) (î 1) (ö 9) (û 1) (œ 1) (ε 2) (λ 12) (μ 1) (ο 2) (ς 1) (τ 1) (а 1) (д 1) (е 1) (з 1) (л 1) (м 1) (н 1) (я 3) (ἄ 1) (— 2) (“ 2) (” 2) (… 184) (→ 465) (∅ 57) (∈ 4) (∏ 1) (∑ 2) (∘ 6) (√ 4)(∞ 12) (∫ 2) (⌚ 2) (⌛ 1) (⏳ 4) (☕ 1) (♠ 7) (♡ 2) (♢ 2) (♣ 6) (♤ 2) (♥ 8) (♦ 8)  (♧ 2) (⚁ 1) (⚃ 2) (⚪ 1) (⛔ 1) (✋ 1) (❄ 1) (❅ 1) (❆ 1) (❇ 1) (❈ 1) (❉ 1) (❊ 1) (❋ 1) (❌ 3) (❍ 1)  (❎ 1) (❗ 1) (➛ 900) (➰ 1) (⭕ 2) ... )    ➛ Total letters:     212631    ➛ Total lines:     4539      `

## Eiffel

`class	APPLICATION create	make feature {NONE} -- Initialization 	make			-- Read from the file and print frequencies.		local			file: PLAIN_TEXT_FILE		do			create file.make_open_read("input.txt")			file.read_stream(file.count)			file.close			across get_frequencies(file.last_string) as f loop				print(f.key.out + ": " + f.item.out + "%N")			end		end feature -- Access 	get_frequencies (s: STRING): HASH_TABLE[INTEGER, CHARACTER]			-- Hash table of counts for alphabetic characters in `s'.		local			char: CHARACTER		do			create Result.make(0)			across s.area as st loop				char := st.item				if char.is_alpha then					if Result.has(char) then						Result.force(Result.at(char) + 1, char)					else						Result.put (1, char)					end				end			end		endend`
Output:
when file contains "Hello, Eiffel world!":
```H: 1
e: 2
l: 4
o: 2
E: 1
i: 1
f: 2
w: 1
r: 1
d: 1```

## Elixir

`file = hd(System.argv) File.read!(file)|> String.upcase|> String.graphemes|> Enum.filter(fn c -> c =~ ~r/[A-Z]/ end)|> Enum.reduce(Map.new, fn c,acc -> Map.update(acc, c, 1, &(&1+1)) end)|> Enum.sort_by(fn {_k,v} -> -v end)|> Enum.each(fn {k,v} -> IO.puts "#{k}  #{v}" end)`
Output:
```C:\Elixir>elixir letterfrequency.exs \work\unixdict.txt
E  20144
A  16421
I  13980
R  13436
T  12836
O  12738
N  12097
S  10210
L  10061
C  8216
U  6489
M  5828
D  5799
P  5516
H  5208
G  4129
B  4115
Y  3633
F  2662
W  1968
K  1925
V  1902
X  617
Z  433
J  430
Q  378
```

## Erlang

`%% Implemented by Arjun Sunel-module(letter_frequency).-export([main/0, letter_freq/1]).main() ->	case  file:read_file("file.txt") of		{ok, FileData} ->			letter_freq(binary_to_list(FileData));		_FileNotExist ->			io:format("File do not exist~n")	end. letter_freq(Data) ->	lists:foreach(fun(Char) ->					LetterCount = lists:foldl(fun(Element, Count) ->											case Element =:= Char of												true ->													Count+1;												false ->													Count											end												end, 0, Data), 					case LetterCount >0 of						true ->												io:format("~p	:	~p~n", [[Char], LetterCount]);						false ->							io:format("")					end						end,  lists:seq(0, 222)).															 `
Output:
```"\n"    :       5
" "     :       4
","     :       1
"."     :       22
":"     :       3
"M"     :       1
"a"     :       2
"e"     :       2
"i"     :       1
"j"     :       1
"l"     :       1
"m"     :       1
"n"     :       3
"r"     :       1
"s"     :       2
"u"     :       2
"y"     :       1
"}"     :       2
ok
```

Alternatively letter_freq/1 above can be replaced with

` letter_freq( Data ) ->	Dict = lists:foldl( fun (Char, Dict) -> dict:update_counter( Char, 1, Dict ) end, dict:new(), Data ),	[io:fwrite( "~p	:	~p~n", [[X], dict:fetch(X, Dict)]) || X <- dict:fetch_keys(Dict)]. `

## ERRE

Using ERRE help file for testing.

`PROGRAM LETTER DIM CNT[255] BEGIN       OPEN("I",1,"f:\errev30\erre.hlp")       REPEAT        GET(#1,A\$)        L%=LEN(A\$)        IF L%>0 THEN          FOR I%=1 TO L% DO            A%=ASC(MID\$(A\$,I%))            CNT[A%]+=1          END FOR        END IF      UNTIL EOF(1)      CLOSE(1)       FOR C%=\$41 TO \$5A DO        PRINT(CHR\$(C%);CHR\$(C%+32);": ";CNT[C%]+CNT[C%+32])      END FOR END PROGRAM `

## Euphoria

Works with: OpenEuphoria
` -- LetterFrequency.ex-- Count frequency of each letter in own source code. include std/console.einclude std/io.einclude std/text.e sequence letters = repeat(0,26) sequence content = read_file("LetterFrequency.ex") content = lower(content) for i = 1 to length(content) do	if content[i] > 96 and content[i] < 123 then		letters[content[i]-96] += 1	end ifend for for i = 1 to 26 do	printf(1,"%s:  %d\n",{i+96,letters[i]})end for if getc(0) then end if `
Output:
```a: 4
b: 0
c: 21
-snip
x: 3
y: 3
z: 0
```

## F#

`let alphabet =    ['A'..'Z'] |> Set.ofList let letterFreq (text : string) =    text.ToUpper().ToCharArray()    |> Array.filter (fun x -> alphabet.Contains(x))    |> Seq.countBy (fun x -> x)    |> Seq.sort let v = "Now is the time for all good men to come to the aid of the party" let res = letterFreq v for (letter, freq) in res do    printfn "%A, %A" letter freq`

## FBSL

The result of the first evaluation of ASC() is retained in the symbol ASC for later use. This is a standard feature of FBSL functions. The ascii array is dynamic. Command(1) is the name of the script file.

`#APPTYPE CONSOLE 'Open a text file and count the occurrences of each letter.FUNCTION countBytes(fileName AS STRING)	DIM c AS STRING	DIM ascii[]	DIM handle AS INTEGER = FILEOPEN(fileName, BINARY)	WHILE NOT FILEEOF(handle)		c = FILEGETC(handle)		IF c = "" THEN EXIT WHILE		ascii[ASC] = ascii[ASC(c)] + 1	WEND	FILECLOSE(handle)	RETURN asciiEND SUB DIM counters = countBytes(COMMAND(1))FOR DIM i = LBOUND(counters) TO UBOUND(counters)	PRINT i, TAB, IIF(i <= 32, i, CHR(i)), TAB, counters[i]NEXT PAUSE `

## Factor

`USING: hashtables locals io assocs kernel io.encodings.utf8 io.files formatting ;IN: count-letters <PRIVATE : count-from-stream ( -- counts )  52 <hashtable>  [ read1 dup ] [ over inc-at ] while  drop ; : print-counts ( counts -- )  [ "%c: %d\n" printf ] assoc-each ; PRIVATE> : count-letters ( filename -- )  utf8 [ count-from-stream ] with-file-reader    print-counts ; `

## Forth

`create counts 26 cells allot : freq ( filename -- )  counts 26 cells erase  slurp-file bounds do    i [email protected] 32 or 'a -    dup 0 26 within if      cells counts +      1 swap +!    else drop then  loop  26 0 do    cr [char] ' emit  'a i + emit  ." ': "    counts i cells + @ .  loop ; s" example.txt" freq`

## Fortran

Using the configuration file (which has changed since the example was documented) of the J example, compilation and output of this program on a gnu/linux system is

` -*- mode: compilation; default-directory: "/tmp/" -*-Compilation started at Sat May 18 18:09:46 a=./F && make \$a && \$a < configuration.filef95 -Wall -ffree-form F.F -o F          92          21          17          24          82          19          19          22          67           0           2          27          27          57          55          31           1          61          43          60          20           6           2           0          10           0 Compilation finished at Sat May 18 18:09:46 `

And here's the FORTRAN90 program source. The program reads stdin and writes the result to stdout. Future enhancement: use block size records.

` ! count letters from stdinprogram LetterFrequency  implicit none  character (len=1) :: s  integer, dimension(26) :: a  integer :: ios, i, t  data a/26*0/,i/0/  open(unit=7, file='/dev/stdin', access='direct', form='formatted', recl=1, status='old', iostat=ios)  if (ios .ne. 0) then    write(0,*)'Opening stdin failed'    stop  endif  do i=1, huge(i)    read(unit=7, rec = i, fmt = '(a)', iostat = ios ) s    if (ios .ne. 0) then      !write(0,*)'ios on failure is ',ios      close(unit=7)      exit    endif    t = ior(iachar(s(1:1)), 32) - iachar('a')    if ((0 .le. t) .and. (t .le. iachar('z'))) then      t = t+1      a(t) = a(t) + 1    endif  end do  write(6, *) aend program LetterFrequency `

## FreeBASIC

`' FB 1.05.0 Win64 Dim a(65 to 90) As Integer  ' array to hold frequency of each letter, all elements zero initiallyDim fileName As String = "input.txt"Dim s As StringDim i As IntegerOpen fileName For Input As #1 While Not Eof(1)  Line Input #1, s  s = UCase(s)  For i = 0 To Len(s) - 1    a(s[i]) += 1  NextWend Close #1 Print "The frequency of each letter in the file "; fileName; " is as follows:"PrintFor i = 65 To 90  If a(i) > 0 Then    Print Chr(i); " : "; a(i)  End IfNextPrintPrint "Press any key to quit"Sleep`
Output:
```/'
results for input.txt which contains the single line:
The quick brown fox jumps over the lazy dog.
'/

The frequency of each letter in the file input.txt is as follows:

A :  1
B :  1
C :  1
D :  1
E :  3
F :  1
G :  1
H :  2
I :  1
J :  1
K :  1
L :  1
M :  1
N :  1
O :  4
P :  1
Q :  1
R :  2
S :  1
T :  2
U :  2
V :  1
W :  1
X :  1
Y :  1
Z :  1
```

Input:

```This is the one question that most people ask. Why bother learning a completely different computing environment, when the operating
system that ships with most desktops, laptops, and servers works just fine? To answer that question, I would pose another question.
Does that operating system you’re currently using really work “just fine”? Or are you constantly battling viruses, malware, slow
downs, crashes, costly repairs, and licensing fees?

If you struggle with the above, and want to free yourself from the constant fear of losing data or having to take your computer in
for the “yearly clean up,” Linux might be the perfect platform for you. Linux has evolved into one of the most reliable computer
ecosystems on the planet. Combine that reliability with zero cost of entry and you have the perfect solution for a desktop platform.
```

## Gambas

`Public Sub Form_Open()Dim sData As String = File.Load("data.txt")Dim iCount, iSpaces, iLetters, iOther As IntegerDim bPunctuation As Boolean For iCount = 1 To Len(sData)  If InStr("ABCDEFGHIJKLMNOPQRSTUVWXYZ", UCase(Mid(sData, iCount, 1))) Then     Inc iLetters    bPunctuation = True  End If   If Mid(sData, icount, 1) = " " Then     Inc iSpaces    bPunctuation = True  End If   If bPunctuation = False Then Inc iOther  bPunctuation = FalseNext Message("Text contains " & Len(sData) & " characters\n" & iLetters & " Letters\n" & iSpaces & " Spaces\n" & iOther & " Punctuation, newlines etc.") End`

Output:

```Text contains 854 characters
677 Letters
135 Spaces
42 Punctuation, newlines etc.
```

## Go

`package main import (    "fmt"    "io/ioutil"    "sort"    "unicode") const file = "unixdict.txt" func main() {    bs, err := ioutil.ReadFile(file)    if err != nil {        fmt.Println(err)        return    }    m := make(map[rune]int)    for _, r := range string(bs) {        m[r]++    }    // answer is now in m.  sort and format output:    lfs := make(lfList, 0, len(m))    for l, f := range m {        lfs = append(lfs, &letterFreq{l, f})    }    sort.Sort(lfs)    fmt.Println("file:", file)    fmt.Println("letter  frequency")    for _, lf := range lfs {        if unicode.IsGraphic(lf.rune) {            fmt.Printf("   %c    %7d\n", lf.rune, lf.freq)        } else {            fmt.Printf("%U  %7d\n", lf.rune, lf.freq)        }    }} type letterFreq struct {    rune    freq int}type lfList []*letterFreq func (lfs lfList) Len() int { return len(lfs) }func (lfs lfList) Less(i, j int) bool {    switch fd := lfs[i].freq - lfs[j].freq; {    case fd < 0:        return false    case fd > 0:        return true    }    return lfs[i].rune < lfs[j].rune}func (lfs lfList) Swap(i, j int) {    lfs[i], lfs[j] = lfs[j], lfs[i]}`
Output:
```file: unixdict.txt
letter  frequency
U+000A    25104
e      20144
a      16421
i      13980
r      13436
t      12836
o      12738
n      12097
s      10210
l      10061
c       8216
u       6489
m       5828
d       5799
p       5516
h       5208
g       4129
b       4115
y       3633
f       2662
w       1968
k       1925
v       1902
x        617
z        433
j        430
q        378
'        105
&          6
.          6
1          2
0          1
2          1
3          1
4          1
5          1
6          1
7          1
8          1
9          1
```

## Groovy

`def frequency = { it.inject([:]) { map, value -> map[value] = (map[value] ?: 0) + 1; map } } frequency(new File('frequency.groovy').text).each { key, value ->    println "'\$key': \$value"}`
Output:
```'d': 1
'e': 19
'f': 4
' ': 29
'r': 5
'q': 3
'u': 8
[lines omitted]
'o': 2
'x': 1
'h': 1
'k': 2
'"': 2
'\$': 2```

## Harbour

`PROCEDURE Main()   LOCAL s := hb_MemoRead( Left( __FILE__ , At( ".", __FILE__ )) +"prg")   LOCAL c, n, i   LOCAL a := {}    FOR EACH c IN s      IF Asc( c ) > 31         AAdd( a, c )      ENDIF   NEXT   a := ASort( a )   i := 1   WHILE i <= Len( a )      c := a[i] ; n := 1      i++      IF i < Len(a) .AND. c == a[i]         WHILE c == a[i]            n++ ; i++         END      ENDIF      ?? "'" + c + "'" + "=" + hb_NtoS( n ) + " "   END    RETURN`
Output:
(counting the printable characters of its own source code):
```' '=190 '"'=12 ' ' '=2 '('=10 ')'=10 '+'=12 ','=5 '.'=3 '1'=3 '3'=1 ':'=6 ';'=2 '<'=2 '='=12
'>'=1 '?'=2 'A'=10 'C'=5 'D'=6 'E'=13 'F'=7 'H'=3 'I'=9 'L'=13 'M'=2 'N'=9 'O'=5 'P'=1
'R'=6 'S'=2 'T'=2 'U'=2 'W'=2 'X'=1 '['=3 ']'=3 '_'=10 'a'=12 'b'=2 'c'=9 'd'=3 'e'=5
'f'=1 'g'=1 'h'=2 'i'=11 'm'=1 'n'=7 'o'=3 'p'=1 'r'=2 's'=3 't'=5 'w'=1 '{'=1 '}'=1
```

Short version:

`import Data.List (group,sort)import Control.Arrow ((&&&))main = interact (show . map (head &&& length) . group . sort)`

## Icon and Unicon

The example below counts (case insensitive) letters and was run on a version of this source file.

`link printf procedure main(A)every PrintCount(CountLetters(!A))    end procedure CountLetters(fn)  #: Return case insensitive count of letters   K := table(0)   if f := open(fn,"r") then {      every c := !map(|read(f)) do          if any(&lcase,c) then K[c] +:= 1      close(f)      return K      }   else write(&errout,"Unable to open file ",fn)end procedure PrintCount(T)    #: Print the letters every c := key(T) do   printf("%s - %d\n",c,T[c])end`
Output:
```c - 17
k - 5
s - 10
h - 2
p - 10
e - 41
m - 2
u - 12
b - 2
r - 25
o - 16
w - 1
d - 10
l - 10
t - 27
a - 10
i - 13
y - 5
f - 12
n - 28
v - 4```

## J

Input is a directory-path with filename. Result is 26 integers representing counts of each letter, in alphabetic order (a's count is first).

`ltrfreq=: 3 : 0  letters=. u: 65 + i.26  NB. upper case letters  <: #/.~ letters (, -. -.~) toupper fread y  )`

Example use (based on a configuration file from another task):

`   ltrfreq 'config.file'88 17 17 24 79 18 19 19 66 0 2 26 26 57 54 31 1 53 43 59 19 6 2 0 8 0`

## Java

Works with: Java version 5+
`import java.io.BufferedReader;import java.io.FileReader;import java.io.IOException;import java.util.Arrays; public class LetterFreq {	public static int[] countLetters(String filename) throws IOException{		int[] freqs = new int[26];		BufferedReader in = new BufferedReader(new FileReader(filename));		String line;		while((line = in.readLine()) != null){			line = line.toUpperCase();			for(char ch:line.toCharArray()){				if(Character.isLetter(ch)){					freqs[ch - 'A']++;				}			}		}		in.close();		return freqs;	} 	public static void main(String[] args) throws IOException{		System.out.println(Arrays.toString(countLetters("filename.txt")));	}}`
Works with: Java version 7+

In Java 7, we can use try with resources. The `countLetters` method would look like this:

`public static int[] countLetters(String filename) throws IOException{	int[] freqs = new int[26];	try(BufferedReader in = new BufferedReader(new FileReader(filename))){		String line;		while((line = in.readLine()) != null){			line = line.toUpperCase();			for(char ch:line.toCharArray()){				if(Character.isLetter(ch)){					freqs[ch - 'A']++;				}			}		}	}	return freqs;}`
Works with: Java version 8+

In Java 8, we can use streams. This code also handles unicode codepoints as well. The `countLetters` method would look like this:

`public static Map<Integer, Long> countLetters(String filename) throws IOException {    return Files.lines(Paths.get(filename))        .flatMapToInt(String::chars)        .filter(Character::isLetter)        .boxed()        .collect(Collectors.groupingBy(Function.identity(), Collectors.counting()));}`

## JavaScript

JavaScript is no longer used only in environments which are carefully isolated from file systems, but JavaScript standards still do not specify standard file-system functions. Leaving aside the particular and variable details of how files will be opened and read in environments like Node.js and OS X JavaScript for Automation etc., we can still use core JavasScript (ES5 in the example below), to count the characters in a text once it has been read from a file system.

`(function(txt) {     var cs = txt.split(''),        i = cs.length,        dct =  {},        c = '',        keys;     while (i--) {        c = cs[i];        dct[c] = (dct[c] || 0) + 1;    }     keys = Object.keys(dct);    keys.sort();    return keys.map(function (c) { return [c, dct[c]]; }); })("Not all that Mrs. Bennet, however, with the assistance of her five\daughters, could ask on the subject, was sufficient to draw from her\husband any satisfactory description of Mr. Bingley. They attacked him\in various ways--with barefaced questions, ingenious suppositions, and\distant surmises; but he eluded the skill of them all, and they were at\last obliged to accept the second-hand intelligence of their neighbour,\Lady Lucas. Her report was highly favourable. Sir William had been\delighted with him. He was quite young, wonderfully handsome, extremely\agreeable, and, to crown the whole, he meant to be at the next assembly\with a large party. Nothing could be more delightful! To be fond of\dancing was a certain step towards falling in love; and very lively\hopes of Mr. Bingley's heart were entertained."); `
Output:
`[[" ", 121], ["!", 1], ["'", 1], [",", 13], ["-", 3], [".", 9], [";", 2], ["B", 3], ["H", 2], ["L", 2], ["M", 3], ["N", 2], ["S", 1], ["T", 2], ["W", 1], ["a", 53], ["b", 13], ["c", 17], ["d", 29], ["e", 82], ["f", 17], ["g", 16], ["h", 36],["i", 44], ["j", 1], ["k", 3], ["l", 34], ["m", 11], ["n", 41], ["o", 40], ["p", 8], ["q", 2], ["r", 35], ["s", 39], ["t", 55], ["u", 20], ["v", 7], ["w", 17], ["x", 2], ["y", 16]]`

## jq

The following program will report the frequency of all characters in the input file, including newlines, returns, etc, provided the file will fit in memory.
` # Input: an array of strings.# Output: an object with the strings as keys,# the values of which are the corresponding frequencies.def counter:  reduce .[] as \$item ( {}; .[\$item] += 1 ) ; # For neatness we sort the keys:explode | map( [.] | implode ) | counter | . as \$counter | keys | sort[] | [., \$counter[.] ]  `
Example:
`jq -s -R -c -f Letter_frequency.jq somefile.txt`
Output:
```["\n",12]
[" ",124]
["#",1]
["\$",8]
["(",4]
[")",4]
["+",3]
[",",4]
["-",4]
[".",9]
["0",3]
["1",7]
[":",2]
[";",2]
["=",4]
...```

## Julia

Works with: Julia version 0.6
`using DataStructures function letterfreq(file::AbstractString; fltr::Function=(_) -> true)    sort(Dict(counter(filter(fltr, readstring(file)))))end display(letterfreq("src/Letter_frequency.jl"; fltr=isalpha))`
Output:
```DataStructures.OrderedDict{Char,Int64} with 29 entries:
'A' => 1
'C' => 1
'D' => 2
'F' => 1
'L' => 3
'S' => 2
'a' => 9
'b' => 1
'c' => 13
'd' => 5
'e' => 30
'f' => 13
'g' => 4
'h' => 10
'i' => 14
'j' => 1
'k' => 3
'l' => 11
'n' => 15
⋮   => ⋮```

## K

`+(?a;#:'=a:,/0:`)`

Example: The file "hello.txt" contains the string "Hello, world!"

`   c:+(?a;#:'=a:,/0:`hello.txt) `
Output:
```(("H";1)
("e";1)
("l";3)
("o";2)
(",";1)
(" ";1)
("w";1)
("r";1)
("d";1)
("!";1))
```

Sort on decreasing occurrences:

`      [email protected]>c[;1] `
Output:
```(("l";3)
("o";2)
("H";1)
("e";1)
(",";1)
(" ";1)
("w";1)
("r";1)
("d";1)
("!";1))
```

## Kotlin

`// version 1.1.2 import java.io.File fun main(args: Array<String>) {    val text = File("input.txt").readText().toLowerCase()    val letterMap = text.filter { it in 'a'..'z' }.groupBy { it }.toSortedMap()    for (letter in letterMap) println("\${letter.key} = \${letter.value.size}")    val sum = letterMap.values.sumBy { it.size }    println("\nTotal letters = \$sum")}`
Output:

'input.txt' just contains two pangrams:

The quick brown fox jumps over the lazy dog. Sphinx of black quartz, judge my vow.

```a = 3
b = 2
c = 2
d = 2
e = 4
f = 2
g = 2
h = 3
i = 2
j = 2
k = 2
l = 2
m = 2
n = 2
o = 6
p = 2
q = 2
r = 3
s = 2
t = 3
u = 4
v = 2
w = 2
x = 2
y = 2
z = 2

Total letters = 64
```

## Liberty BASIC

Un-rem a line to convert to all-upper-case. Letter freq'y is printed as percentages.

`     open "text.txt" for input as #i        txt\$ =input\$( #i, lof( #i))        Le =len( txt\$)    close #i     dim LetterFreqy( 255)     '   txt\$ =upper\$( txt\$)     for i =1 to Le        char =asc( mid\$( txt\$, i, 1))        if char >=32 then LetterFreqy( char) =LetterFreqy( char) +1    next i     for j =32 to 255        if LetterFreqy( j) <>0 then print " Character #"; j, "("; chr\$( j);_         ") appeared "; using( "##.##", 100 *LetterFreqy( j) /Le); "% of the time."    next j     end `

## Lasso

`local(	str 	= 'Hello world!',	freq	= map)// as a loop. arguably quicker than query expressionloop(#str->size) => {	#freq->keys !>> #str->get(loop_count) ? 		#freq->insert(#str->get(loop_count) = #str->values->find(#str->get(loop_count))->size)} // orlocal(	str 	= 'Hello world!',	freq	= map)// as query expression, less codewith i in #str->values where #freq->keys !>> #i do => {	#freq->insert(#i = #str->values->find(#i)->size)} // output #freqwith elem in #freq->keys do => {^	'"'+#elem+'": '+#freq->find(#elem)+'\r'^}`

## Lua

This solution counts letters only, which could be changed by altering the pattern argument to 'gmatch' on line 31. It also treats upper and lower case letters as distinct, which could be changed by changing everything to upper or lower case with string.upper() or string.lower() before tallying.

`-- Return entire contents of named filefunction readFile (filename)  local file = assert(io.open(filename, "r"))  local contents = file:read("*all")  file:close()  return contentsend -- Return a closure to keep track of letter countsfunction tally ()  local t = {}   -- Add x to tally if supplied, return tally list otherwise  local function count (x)    if x then      if t[x] then        t[x] = t[x] + 1      else        t[x] = 1      end    else      return t    end  end   return countend -- Main procedurelocal letterCount = tally()for letter in readFile(arg[1]):gmatch("%a") do  letterCount(letter)endfor k, v in pairs(letterCount()) do  print(k, v)end`

Output from running this script on itself:

```i       24
g       2
h       4
e       61
f       16
c       19
d       17
R       2
o       31
p       7
m       4
n       42
k       4
l       40
y       4
w       1
x       7
u       18
v       2
s       14
t       54
a       24
C       3
M       1
A       1
F       2
r       32```

## M2000 Interpreter

` document file1\$={Open a text file and count the occurrences of each letter.		Some of these programs count all characters (including punctuation), but some only count letters A to Z		}const Ansi=3, nl\$=chr\$(13)+chr\$(10), Console=-2save.doc file1\$, "checkdoc.txt", Ansiopen "checkdoc.txt" for input as Fbuffer onechar as bytem=0dim m(65 to 90)while not eof(#F)	get #F, onechar	a\$=chr\$(eval(onechar,0))	if a\$ ~ "[A-Za-z]" then		m++		m(asc(ucase\$(a\$)))++	end ifend whileclose #Fdocument Export\$for i=65 to 90	if m(i)>0 then Export\$=format\$("{0} - {1:2:4}%",chr\$(i),m(i)/m*100)+nl\$nextprint #Console, Export\$clipboard Export\$ `
Output:
```A - 6,87%
B - 0,76%
C - 8,40%
D - 1,53%
E - 12,2%
F - 2,29%
G - 1,53%
H - 3,05%
I - 3,05%
L - 5,34%
M - 2,29%
N - 8,40%
O - 9,92%
P - 2,29%
R - 6,11%
S - 5,34%
T - 12,2%
U - 6,11%
X - 0,76%
Y - 0,76%
Z - 0,76%
```

## Maple

`StringTools:-CharacterFrequencies(readbytes("File.txt",infinity,TEXT))`

## Mathematica / Wolfram Language

`Tally[Characters[Import["file.txt","Text"]]]`

## MATLAB / Octave

`function u = letter_frequency(t)	if ischar(t)		t = abs(t);	end; 	A = sparse(t+1,1,1,256,1);	printf('"%c":%i\n',[find(A)-1,A(A>0)]')end`

## NetRexx

Translation of: REXX
`/* NetRexx ************************************************************* 22.05.2013 Walter Pachl  translated from REXX**********************************************************************/options replace format comments java crossref symbols nobinary   parse arg dsn .  if dsn = '' then    dsn = 'test.txt'  cnt=0  totChars=0                         /*count of the total num of chars*/  totLetters=0                       /*count of the total num letters.*/  indent=' '.left(20)                /*used for indentation of output.*/  lines = scanFile(dsn)  loop l_ = 1 to lines[0]    line = lines[l_]     Say '>'line'<' line.length       /* that's in test.txt            */    /*    lrx=left_right(line)    Parse lrx leftx rightx    Say ' 'leftx    Say ' 'rightx    */    loop k=1 for line.length()       /*loop over characters           */      totChars=totChars+1            /*Increment total number of chars*/      c=line.substr(k,1)             /*get character number k         */      cnt[c]=cnt[c]+1                /*increment the character's count*/      End    end l_   w=totChars.length                  /*used for right-aligning counts.*/  say 'file -----' dsn "----- has" lines[0] 'records.'  say 'file -----' dsn "----- has" totChars 'characters.'  Loop L=0 to 255                    /* display nonzero letter counts */    c=l.d2c                          /* the character in question     */    if cnt[c]>0 & c.datatype('M')>0 Then Do /* was found in the file  */                                     /* and is a latin letter         */      say indent "(Latin) letter " c 'count:' cnt[c].right(w) /* tell */      totLetters=totLetters+cnt[c]   /* increment number of letters   */      End    End   say 'file -----' dsn "----- has" totLetters '(Latin) letters.'  say '                           other charactes follow'  other=0  loop m=0 to 255                    /* now for non-letters           */    c=m.d2c                          /* the character in question     */    y=c.c2x                          /* the hex representation        */    if cnt[c]>0 & c.datatype('M')=0 Then Do /* was found in the file  */                                     /* and is not a latin letter     */      other=other+cnt[c]             /* increment count               */      _=cnt[c].right(w)              /* prepare output of count       */      select                         /*make the character viewable.   */       when c<<' ' | m==255 then say indent "'"y"'x character count:" _       when c==' '          then say indent "blank character count:" _       otherwise                 say indent "   " c 'character count:' _       end     end   end  say 'file -----' dsn "----- has" other 'other characters.'  say 'file -----' dsn "----- has" totLetters 'letters.' -- Read a file and return contents as a Rexx indexed stringmethod scanFile(dsn) public static returns Rexx   fileLines = ''  do    inFile = File(dsn)    inFileScanner = Scanner(inFile)    loop l_ = 1 while inFileScanner.hasNext()      fileLines[0] = l_      fileLines[l_] = inFileScanner.nextLine()      end l_    inFileScanner.close()   catch ex = FileNotFoundException    ex.printStackTrace  end   return fileLines`

## Nim

`import tables, os var t = initCountTable[char]()var f = open(paramStr(1))for l in f.lines:  for c in l:    t.inc(c)echo t`

## Objeck

` use IO; bundle Default {  class Test {    function : Main(args : String[]) ~ Nil {      freqs := CountLetters("filename.txt");      for(i := 'A'; i < 'Z'; i += 1;) {        Console->Print(i->As(Char))->Print("=>")->PrintLine(freqs[i - 'A']);      };    }     function : CountLetters(filename : String) ~ Int[] {      freqs := Int->New[26];      reader := FileReader->New(filename);      while(reader->IsEOF() <> true) {        line := reader->ReadString()->ToUpper();        each(i : line) {          ch := line->Get(i);          if(ch->IsChar()){            index := ch - 'A';            freqs[index] := freqs[index] + 1;          };        };      };      reader->Close();       return freqs;    }  }}   `

## Objective-C

`#import <Foundation/Foundation.h> int main (int argc, const char *argv[]) {  @autoreleasepool {     NSData *data = [NSData dataWithContentsOfFile:@(argv[1])];    NSString *string = [[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding];    NSCountedSet *countedSet = [[NSCountedSet alloc] init];    NSUInteger len = [string length];    for (NSUInteger i = 0; i < len; i++) {      unichar c = [string characterAtIndex:i];      if ([[NSCharacterSet letterCharacterSet] characterIsMember:c])        [countedSet addObject:@(c)];    }    for (NSNumber *chr in countedSet) {      NSLog(@"%C => %lu", (unichar)[chr integerValue], [countedSet countForObject:chr]);    }   }  return 0;}`

## OCaml

We open a text file and compute letter frequency. Other characters than [a-z] and [A-Z] are ignored, and upper case letters are first converted to lower case before to compute letter frequency.

`let () =  let ic = open_in Sys.argv.(1) in  let base = int_of_char 'a' in  let arr = Array.make 26 0 in  try while true do    let c = Char.lowercase(input_char ic) in    let ndx = int_of_char c - base in    if ndx < 26 && ndx >= 0 then      arr.(ndx) <- succ arr.(ndx)  done  with End_of_file ->    close_in ic;    for i=0 to 25 do      Printf.printf "%c -> %d\n" (char_of_int(i + base)) arr.(i)    done`

If we want to compute all characters in an UTF8 file, we must use an external library, for example Batteries. The following function takes as input a string that contains the path to the file, and prints all the characters together with their frequencies, ordered by increasing frequencies, on the standard output.

` open Batteries let frequency file =   let freq = Hashtbl.create 52 in    File.with_file_in file      (Enum.iter (fun c -> Hashtbl.modify_def 1 c succ freq) % Text.chars_of);    List.iter (fun (k,v) -> Text.write_text stdout k;                             Printf.printf " %d\n" v)    @@ List.sort (fun (_,v) (_,v') -> compare v v')    @@ Hashtbl.fold (fun k v l -> (Text.of_uchar k,v) :: l) freq [] `

## OxygenBasic

` indexbase 0 sys a,e,i,c[255] string s=getfile "t.txt" e=len s for i=1 to e  a=asc(s,i)  ++c(a)next cr=chr(13)+chr(10)pr="Char Frequencies" cr crfor i=32 to 255  pr+=chr(i) chr(9) c(i) crnext print pr'putfile "CharCount.txt",pr `

## PARI/GP

`v=vector(26);U=readvec("foo.txt");for(i=1,#U,u=Vecsmall(U[i]);for(j=1,#u,if(u[j]>64&&u[j]<91,v[u[j]-64]++,u[j]>96&&u[j]<123,v[u[j]-96]++)));v`

## Pascal

`program LetterFrequency;var  textFile: text;  character: char;  counter: array[0..255] of integer;  i: integer;begin  for i := low(counter) to high(counter) do    counter[i] := 0;  assign(textFile, 'a_text_file.txt');  reset(textFile);  while not eof(textFile) do  begin    while not eoln(textFile) do    begin      read(textFile, character);      inc(counter[ord(character)]);    end;    readln(textFile);  end;  for i := low(counter) to high(counter) do    if counter[i] > 0 then      writeln(char(i), ': ', counter[i]);end. `
Output:
```>: ./LetterFrequency
3: 2
a: 4
d: 3
e: 3
f: 3
g: 2
q: 1
r: 4
s: 3
t: 2
w: 2```

## Perl

Counts letters in files given on command line or piped to stdin. Case insensitive.

`while (<>) { \$cnt{lc chop}++ while length }print "\$_: ", \$cnt{\$_}//0, "\n" for 'a' .. 'z';`

## Perl 6

In perl6, whenever you want to count things in a collection, the rule of thumb is to use the Bag structure.

`.&ws.say for slurp.comb.Bag.sort: -*.value; sub ws (\$pair) {     \$pair.key ~~ /\n/    ?? ('NEW LINE' => \$pair.value)    !! \$pair.key ~~ /\s/    ?? (\$pair.key.uniname => \$pair.value)    !! \$pair}`
Output when fed the same Les Misérables text file as used in the Word count task:
```SPACE => 522095
e => 325692
t => 222916
a => 199790
o => 180974
h => 170210
n => 167006
i => 165201
s => 157585
r => 145118
d => 106987
l => 97131
NEW LINE => 67662
u => 67340
c => 62717
m => 56021
f => 53494
w => 53301
, => 48784
g => 46060
p => 39932
y => 37985
b => 34276
. => 30589
v => 24045
" => 14340
k => 14169
T => 12547
- => 11037
I => 10067
A => 7355
H => 6600
M => 6206
; => 5885
E => 4968
C => 4583
S => 4392
' => 3938
x => 3692
! => 3539
R => 3531
P => 3424
O => 3401
j => 3390
B => 3185
W => 3180
N => 3053
? => 2976
F => 2754
G => 2508
: => 2468
J => 2448
L => 2444
q => 2398
V => 2200
_ => 2070
z => 1847
D => 1756
é => 1326
Y => 1238
U => 895
1 => 716
8 => 412
X => 333
K => 321
è => 292
3 => 259
2 => 248
5 => 220
0 => 218
* => 181
4 => 181
) => 173
( => 173
6 => 167
É => 146
7 => 143
Q => 135
] => 122
[ => 122
9 => 117
æ => 106
= => 75
ê => 74
Z => 59
à => 59
â => 56
> => 50
< => 50
/ => 50
ç => 48
NO-BREAK SPACE => 45
î => 39
ü => 37
| => 36
ô => 34
# => 26
ù => 18
ï => 18
Æ => 10
û => 9
+ => 5
È => 5
ë => 5
À => 4
@ => 2
ñ => 2
Ç => 2
\$ => 2
% => 1
& => 1
{ => 1
} => 1
½ => 1
```

## Phix

Counts own source or supplied filename

`sequence lc = repeat(0,#7E)integer fn = open(command_line()[\$],"rb"), chwhile 1 do    ch = getc(fn)    if ch=-1 then exit end if    if ch>=' ' and ch<#7F then        lc[ch] += 1    end ifend whileclose(fn) for i=' ' to #7E do    if lc[i]!=0 then        printf(1,"'%c': %d%s",{i,lc[i],iff(mod(i,32)=31?'\n':'\t')})    end ifend for{} = wait_key()`
Output:
```' ': 77 '!': 1  '"': 4  '#': 3  '\$': 1  '%': 3  ''': 10 '(': 9  ')': 9  '+': 1  ',': 8  '-': 1  '0': 2  '1': 5  '2': 1  '3': 2  '7': 3  ':': 2  '<': 1  '=': 10 '>': 1  '?': 1
'E': 2  'F': 1  '[': 4  '\': 2  ']': 4  '_': 2
'a': 4  'b': 1  'c': 15 'd': 11 'e': 23 'f': 14 'g': 2  'h': 11 'i': 19 'k': 1  'l': 8  'm': 3  'n': 19 'o': 9  'p': 3  'q': 1  'r': 6  's': 3  't': 11 'u': 1  'w': 3  'x': 1    'y': 1  '{': 2  '}': 2
```

## PHP

`<?phpprint_r(array_count_values(str_split(file_get_contents(\$argv[1]))));?>`

## PicoLisp

`(let Freq NIL   (in "file.txt"      (while (char) (accu 'Freq @ 1)) )   (sort Freq) )`

For a "file.txt":

```abcd
cdef```
Output:
`-> (("^J" . 2) ("a" . 1) ("b" . 1) ("c" . 2) ("d" . 2) ("e" . 1) ("f" . 1))`

## PL/I

` frequencies: procedure options (main);   declare tallies(26) fixed binary static initial ((26) 0);   declare alphabet character (26) static initial      ('ABCDEFGHIJKLMNOPQRSTUVWXYZ');   declare c character (1), i fixed binary;   declare in file;    open file (in) title ('/LETTER.DAT,type(text),recsize(200)') input;    on endfile (in) go to prepare_list;    do while('1'b);      get file (in) edit (c) (a(1)); put edit (c) (a);      i = index(alphabet, c);      if i > 0 then tallies(i) = tallies(i) + 1;   end; prepare_list:   put skip list('Letter', 'Frequency');   do i = 1 to 26;      if tallies(i) > 0 then         put skip list (substr(alphabet, i, 1), tallies(i));   end;end frequencies;`

Data:

```THEQUICKBROWNFOX
JUMPSOVERTHELAZYDOG
```
Output:
```Letter                  Frequency
A                               1
B                               1
C                               1
D                               1
E                               3
F                               1
G                               1
H                               2
I                               1
J                               1
K                               1
L                               1
M                               1
N                               1
O                               4
P                               1
Q                               1
R                               2
S                               1
T                               2
U                               2
V                               1
W                               1
X                               1
Y                               1
Z                               1
```

## PowerShell

` function frequency (\$string) {    \$arr = \$string.ToUpper().ToCharArray() |where{\$_ -match '[A-KL-Z]'}     \$n = \$arr.count    \$arr | group | foreach{        [pscustomobject]@{letter = "\$(\$_.name)"; frequency  = "\$([math]::round(\$(\$_.Count/\$n),5))"; count = "\$(\$_.count)"}    } | sort letter}\$file = "\$(\$MyInvocation.MyCommand.Name )" #Put the name of your file herefrequency \$(get-content \$file -Raw) `

Output:

```letter frequency count
------ --------- -----
A      0.06809   16
B      0.00426   1
C      0.06809   16
D      0.00851   2
E      0.11064   26
F      0.0383    9
G      0.01702   4
H      0.02979   7
I      0.03404   8
J      0.00426   1
K      0.00426   1
L      0.02553   6
M      0.04255   10
N      0.09362   22
O      0.08085   19
P      0.02128   5
Q      0.01277   3
R      0.10638   25
S      0.02128   5
T      0.10213   24
U      0.05957   14
V      0.00426   1
W      0.00851   2
Y      0.02979   7
Z      0.00426   1
```

## Prolog

Works with SWI-Prolog.
Only alphabetic codes are computed in uppercase state.
Uses packlist/2 defined there : Run-length encoding#Prolog

`frequency(File) :-	read_file_to_codes(File, Code, []), 	% we only keep alphabetic codes	include(my_code_type, Code, LstCharCode), 	% we translate char_codes into uppercase atoms.	maplist(my_upcase, LstCharCode, LstChar), 	% sort and pack the list	msort(LstChar, SortLstChar),	packList(SortLstChar, Freq),	maplist(my_write, Freq).  my_write([Num, Atom]) :-	swritef(A, '%3r', [Num]),	writef('Number of %w :%w\n', [Atom, A]).  my_code_type(Code) :-	code_type(Code, alpha). my_upcase(CharCode, UpChar) :-	char_code(Atom, CharCode),	upcase_atom(Atom, UpChar). :- use_module(library(clpfd)).%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% ?- packList([a,a,a,b,c,c,c,d,d,e], L).%  L = [[3,a],[1,b],[3,c],[2,d],[1,e]] .%% ?- packList(R,  [[3,a],[1,b],[3,c],[2,d],[1,e]]).% R = [a,a,a,b,c,c,c,d,d,e] .%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%packList([],[]). packList([X],[[1,X]]) :-	!. packList([X|Rest],[XRun|Packed]):-	run(X,Rest, XRun,RRest),	packList(RRest,Packed). run(Var,[],[1,Var],[]). run(Var,[Var|LRest],[N1, Var],RRest):-	N #> 0,	N1 #= N + 1,	run(Var,LRest,[N, Var],RRest). run(Var,[Other|RRest], [1,Var],[Other|RRest]):-	dif(Var,Other). `
Output:
for this file
```Number of A : 63
Number of B :  7
Number of C : 53
Number of D : 29
Number of E : 65
...
Number of T : 52
Number of U : 20
Number of V : 10
Number of W :  8
Number of X :  6
Number of Y : 12
true .
```

## PureBasic

Alphabetic codes are converted to uppercase before being used and no other codes are used as part of the calculations.

`Procedure countLetters(Array letterCounts(1), textLine.s)  ;counts only letters A -> Z, uses index 0 of letterCounts() to keep a total of all counts  Protected i, lineLength = Len(textLine), letter   textLine = UCase(textLine)  For i = 1 To lineLength    letter = Asc(Mid(textLine, i, 1)) - 'A' + 1    If letter >= 1 And letter <= 26      letterCounts(letter) + 1 ;tally individual letter count      letterCounts(0) + 1      ;increment total letter count    EndIf  NextEndProcedure If OpenConsole()  Define filename.s, fileID, i  filename = OpenFileRequester("Select text file to examine", "*.txt", "Text (*.txt)|*.txt;|All files (*.*)|*.*", 0)  fileID = 0  If ReadFile(fileID, filename)    Dim letterCounts(26) ;A - Z only, index 0 contains the total of all letter counts     Define textLine.s    While Not Eof(fileID)      textLine = ReadString(fileID)      countLetters(letterCounts(), textLine)    Wend    CloseFile(fileID)     PrintN("File: " + filename + #CRLF\$)    PrintN("Letter  %Freq  Count")    For i = 1 To 26      Print("  " + Chr(64 + i) + "     ")      Print(RSet(StrF(100 * letterCounts(i) / letterCounts(0), 1), 5, " ") + "  ")      PrintN(Str(letterCounts(i)))    Next     PrintN(#CRLF\$ + "Total letter count in file: " + Str(letterCounts(0)))  EndIf    Print(#CRLF\$ + #CRLF\$ + "Press ENTER to exit"): Input()  CloseConsole()EndIf`
Output:
```File: D:\_T\Text\dictionary.txt

Letter  %Freq  Count
A       7.6  27743
B       2.0  7248
C       4.3  15433
D       3.8  13798
E      11.8  42917
F       1.4  5030
G       2.8  10336
H       2.1  7720
I       8.6  31141
J       0.2  588
K       0.8  2964
L       5.3  19399
M       2.7  9821
N       7.1  25682
O       6.1  22084
P       2.9  10696
Q       0.2  714
R       7.5  27055
S       8.0  28898
T       7.1  25773
U       3.3  12032
V       1.1  4019
W       0.9  3348
X       0.3  1096
Y       1.7  6251
Z       0.3  1177

Total letter count in file: 362963```

## Python

### Functional

#### Using collections.Counter

Works with: Python version 2.7+ and 3.1+
`import collections, sys def filecharcount(openfile):    return sorted(collections.Counter(c for l in openfile for c in l).items()) f = open(sys.argv[1])print(filecharcount(f))`

#### As a fold

Character counting can be conveniently expressed in terms of fold/reduce. See the example below, which also generates column-wrapped output:

Works with: Python version 3
`'''Character counting as a fold''' from functools import reducefrom itertools import repeatfrom os.path import expanduser  # charCounts :: String -> Dict Char Intdef charCounts(s):    '''A dictionary of       (character, frequency) mappings    '''    def tally(dct, c):        dct[c] = 1 + dct[c] if c in dct else 1        return dct    return reduce(tally, list(s), {})  # TEST ----------------------------------------------------# main :: IO ()def main():    '''Listing in descending order of frequency.'''     print(        tabulated(            'Descending order of frequency:\n'        )(compose(repr)(fst))(compose(str)(snd))(            5        )(stet)(            sorted(                charCounts(                    readFile('~/Code/charCount/readme.txt')                ).items(),                key=swap,                reverse=True            )        )    )  # GENERIC ------------------------------------------------- # chunksOf :: Int -> [a] -> [[a]]def chunksOf(n):    '''A series of lists of length n,       subdividing the contents of xs.       Where the length of xs is not evenly divible,       the final list will be shorter than n.'''    return lambda xs: reduce(        lambda a, i: a + [xs[i:n + i]],        range(0, len(xs), n), []    ) if 0 < n else []  # compose (<<<) :: (b -> c) -> (a -> b) -> a -> cdef compose(g):    '''Right to left function composition.'''    return lambda f: lambda x: g(f(x))  # fst :: (a, b) -> adef fst(tpl):    '''First member of a pair.'''    return tpl[0]  # readFile :: FilePath -> IO Stringdef readFile(fp):    '''The contents of any file at the path       derived by expanding any ~ in fp.'''    with open(expanduser(fp), 'r', encoding='utf-8') as f:        return f.read()  # paddedMatrix :: a -> [[a]] -> [[a]]def paddedMatrix(v):    ''''A list of rows padded to equal length        (where needed) with instances of the value v.'''    def go(rows):        return paddedRows(            len(max(rows, key=len))        )(v)(rows)    return lambda rows: go(rows) if rows else []  # paddedRows :: Int -> a -> [[a]] -[[a]]def paddedRows(n):    '''A list of rows padded (but never truncated)       to length n with copies of value v.'''    def go(v, xs):        def pad(x):            d = n - len(x)            return (x + list(repeat(v, d))) if 0 < d else x        return list(map(pad, xs))    return lambda v: lambda xs: go(v, xs) if xs else []  # showColumns :: Int -> [String] -> Stringdef showColumns(n):    '''A column-wrapped string       derived from a list of rows.'''    def go(xs):        def fit(col):            w = len(max(col, key=len))             def pad(x):                return x.ljust(4 + w, ' ')            return ''.join(map(pad, col)).rstrip()         q, r = divmod(len(xs), n)        return '\n'.join(map(            fit,            zip(*paddedMatrix('')(                chunksOf(q + int(bool(r)))(xs)            ))        ))    return lambda xs: go(xs)  # snd :: (a, b) -> bdef snd(tpl):    '''Second member of a pair.'''    return tpl[1]  # stet :: a -> adef stet(x):    '''The identity function.       The usual 'id' is reserved in Python.'''    return x  # swap :: (a, b) -> (b, a)def swap(tpl):    '''The swapped components of a pair.'''    return (tpl[1], tpl[0])  # tabulated :: String -> (a -> String) ->#                        (b -> String) ->#                        Int ->#                        (a -> b) -> [a] -> Stringdef tabulated(s):    '''Heading -> x display function -> fx display function ->          number of columns -> f -> value list -> tabular string.'''    def go(xShow, fxShow, intCols, f, xs):        def mxw(fshow, g):            return max(map(compose(len)(fshow), map(g, xs)))        w = mxw(xShow, lambda x: x)        fw = mxw(fxShow, f)        return s + '\n' + showColumns(intCols)([            xShow(x).rjust(w, ' ') + ' -> ' + (                fxShow(f(x)).rjust(fw, ' ')            )            for x in xs        ])    return lambda xShow: lambda fxShow: lambda nCols: (        lambda f: lambda xs: go(            xShow, fxShow, nCols, f, xs        )    )  # MAIN ---if __name__ == '__main__':    main()`
Output:
```Descending order of frequency:

' ' -> 568     ')' ->  62     'v' ->  25     'w' ->   7     '5' ->   3
'\t' -> 382     '(' ->  62     '1' ->  24     'k' ->   7     '4' ->   3
'e' -> 274     'd' ->  60     'G' ->  22     '9' ->   6     '+' ->   3
'n' -> 233     'g' ->  59     ']' ->  17     'S' ->   5     '¬' ->   2
'\n' -> 228     'u' ->  58     '[' ->  17     'R' ->   5     '=' ->   2
't' -> 204     '|' ->  54     'λ' ->  16     'M' ->   5     '.' ->   2
's' -> 198     'x' ->  53     '2' ->  15     'F' ->   5     'L' ->   1
'-' -> 178     'm' ->  52     'N' ->  11     '<' ->   5     'C' ->   1
'i' -> 145     'c' ->  52     '}' ->  10     '6' ->   5     'A' ->   1
'o' -> 126     'h' ->  47     '{' ->  10     'z' ->   4     '3' ->   1
'f' -> 100     ':' ->  47     'T' ->  10     "'" ->   4     '&' ->   1
'r' ->  96     ',' ->  38     'I' ->  10     '^' ->   3     '\$' ->   1
'a' ->  86     'b' ->  32     '0' ->  10     'E' ->   3
'l' ->  70     'y' ->  31     '"' ->  10     '8' ->   3
'p' ->  68     '>' ->  28     'J' ->   9     '7' ->   3```

### Procedural

#### Without using collections.Counter

`import stringif hasattr(string, 'ascii_lowercase'):    letters = string.ascii_lowercase       # Python 2.2 and laterelse:    letters = string.lowercase             # Earlier versionsoffset = ord('a') def countletters(file_handle):    """Traverse a file and compute the number of occurences of each letter    return results as a simple 26 element list of integers."""    results = [0] * len(letters)    for line in file_handle:        for char in line:            char = char.lower()            if char in letters:                results[ord(char) - offset] += 1                # Ordinal minus ordinal of 'a' of any lowercase ASCII letter -> 0..25    return results if __name__ == "__main__":    sourcedata = open(sys.argv[1])    lettercounts = countletters(sourcedata)    for i in xrange(len(lettercounts)):        print "%s=%d" % (chr(i + ord('a')), lettercounts[i]),`

This example defines the function and provides a sample usage. The if ... __main__... line allows it to be cleanly imported into any other Python code while also allowing it to function as a standalone script. (A very common Python idiom).

Using a numerically indexed array (list) for this is artificial and clutters the code somewhat.

#### Using defaultdict

Works with: Python version 2.5+ and 3.x
`...from collections import defaultdictdef countletters(file_handle):    """Count occurences of letters and return a dictionary of them    """    results = defaultdict(int)    for line in file_handle:        for char in line:            if char.lower() in letters:                c = char.lower()                results[c] += 1    return results`

Which eliminates the ungainly fiddling with ordinal values and offsets in function countletters of a previous example above. More importantly it allows the results to be more simply printed using:

`lettercounts = countletters(sourcedata)for letter,count in lettercounts.iteritems():    print "%s=%s" % (letter, count),`

Again eliminating all fussing with the details of converting letters into list indices.

## R

`letter.frequency <- function(filename){    file <- paste(readLines(filename), collapse = '')    chars <- strsplit(file, NULL)[[1]]    summary(factor(chars))}`

Usage on itself:

`> source('letter.frequency.r')> letter.frequency('letter.frequency.r')    -  ,  .  '  (  )  [  ]  {  }  <  =  1  a  c  d  e  f  h  i  l  L  m  n  N  o  p  q  r  s  t  u  U  y 22  3  2  1  2  6  6  2  2  1  1  3  1  1  9  6  1 14  7  2  7  8  3  4  6  1  3  3  1  8  8  7  3  1  2 `

## Racket

` #lang racket(require math) (define (letter-frequencies ip)  (count-samples   (port->list read-char ip))) (letter-frequencies (open-input-string "abaabdc")) `
Output:
```'(#\a #\b #\d #\c)
'(3 2 1 1)
```

Using input from a text file:

` (letter-frequencies (open-input-file "somefile.txt")) `

## Raven

`define count_letters use \$words   { } as \$wordHash    [ ] as \$keys   [ ]  as \$vals   \$words each chr      dup \$wordHash swap get 0 prefer 1 +   # stack: chr cnt      swap \$wordHash swap set   \$wordHash keys copy sort each      dup \$keys push      \$wordHash swap get \$vals push   \$keys \$vals combine  print "\n" print "test.dat" as \$file\$file read as \$all_data\$all_data count_letters`

## REXX

### version 1

It should be noted that the file being read is read one line at time, so the
line-end characters (presumably the line-feed, carriage return, new-line, or
whatever control characters are being used) are not reported.
These characters could be read and reported if the   charin   BIF would be used instead of the   linein   BIF.

Also note that this REXX program is ASCII or EBCDIC independent, but what constitutes a letter is restricted to
the Latin (Roman) alphabet (that is, which characters are considered to be letters of a particular language.

The version of REXX that was used was the English version of Regina REXX.   It should be noted that almost all
REXX interpreters assume the English language for such things as determining what characters are considered
letters unless another language is specified   (Regina REXX uses an environmental variable for this purpose).

All characters are still counted, whether a letter or not, including non-displayable characters.

`/*REXX program counts the occurrences of all characters in a file, & note that*//*     all Latin alphabet letters are uppercased for counting {Latin} letters.*//*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~*/abc = 'abcdefghijklmnopqrstuvwxyz'     /*define an (Latin or English) alphabet*/abcU= 'ABCDEFGHIJKLMNOPQRSTUVWXYZ'     /*define an uppercase version of  [↑]. */parse arg fileID .                     /*this last char isn't a middle dot: · */if fileID==''  then fileID='JUNK.TXT'  /*¿none specified? Then use the default*/totChars=0;    totLetters=0            /*count of all chars and of all letters*/pad=left('',18);    pad9=left('',18%2) /*used for the indentations of output. */@.=0                                   /*wouldn't it be neat to use Θ instead?*/     do j=1  while lines(fileID)\==0   /*read the file 'til the cows come home*/     rec=linein(fileID)                /*get a line/record from the input file*/                                       /* [↓]  process all characters in  REC.*/       do k=1  for length(rec)         /*examine/count each of the characters.*/       totChars=totChars+1             /*bump count of number of characters.  */       c=substr(rec,k,1);  @.[email protected].c+1   /*Peel off a character; bump its count.*/       if \datatype(c,'M') then iterate  /*Not a Latin letter?  Get next char.*/       totLetters=totLetters+1         /*bump the count for [Latin] letters.  */       upper c   /* ◄«««««««««««««««««««««««««««◄ uppercase a Latin character.*/       @..[email protected]..c+1                     /*bump the (Latin) letter's count.     */       end   /*k*/                     /*no Greek glyphs: π Γ Σ µ α ß Φ ε δ σ */     end     /*j*/                     /*maybe we're ½ done by now, or maybe ¬*/                                           LL= '(Latin) letter'w=length(totChars)                     /*used for right─aligning the counts.  */say 'file ─────' fileId "───── has" j-1 'records and has' totLetters LL"s."; say  do L=0  for 256;    c=d2c(L)         /*display all none─zero letter counts. */  if @..c==0  then iterate             /*A zero count?  Then ignore character.*/  say pad9  LL' '   c   " (also" translate(c,abc,abcU)')  count:'  right(@..c,w)  end   /*L*/                          /*we may be in a rut, but not a cañyon.*/ say;    say 'file ─────'  fileId   "───── has"   totChars   'unique characters.'say     do #=0  for 256;    y=d2c(#)      /*display all none─zero char counts.   */     if @.y==0  then iterate           /*A zero count?  Then ignore character.*/     c=d2c(#);  ch=c                   /*C  is the character glyph of a char. */     if c<<' ' | #==255  then ch=      /*don't show control characters or null*/     if c==' '           then ch='blank'                /*show a blank's name.*/     say pad right(ch,5)     " ('"d2x(#,2)"'x  character count:"    right(@.c,w)     end   /*#*/                       /*255 isn't quite ∞, but sometimes ∙∙∙ */say                                    /*not a good place for dithering: ░▒▓█ */say  pad   pad9   '☼ end─of─list ☼'    /*show we are at the end of the list.  */                                       /*stick a fork in it, we're all done. ☻*/`

output   when using the (above) REXX program for the input file:

Note that this REXX program works with ASCII or EBCDIC, but the order of the output will
be different because of the order in which EBCDIC and ASCII stores characters.

```file ───── countfrq.rex ───── has 42 records and has 1540 (Latin) letters.

(Latin) letter  A  (also a)  count:  133
(Latin) letter  B  (also b)  count:   23
(Latin) letter  C  (also c)  count:  101
(Latin) letter  D  (also d)  count:   55
(Latin) letter  E  (also e)  count:  176
(Latin) letter  F  (also f)  count:   49
(Latin) letter  G  (also g)  count:   23
(Latin) letter  H  (also h)  count:   73
(Latin) letter  I  (also i)  count:   86
(Latin) letter  J  (also j)  count:    6
(Latin) letter  K  (also k)  count:   11
(Latin) letter  L  (also l)  count:   91
(Latin) letter  M  (also m)  count:   20
(Latin) letter  N  (also n)  count:  101
(Latin) letter  O  (also o)  count:   97
(Latin) letter  P  (also p)  count:   35
(Latin) letter  Q  (also q)  count:    4
(Latin) letter  R  (also r)  count:  107
(Latin) letter  S  (also s)  count:   81
(Latin) letter  T  (also t)  count:  164
(Latin) letter  U  (also u)  count:   47
(Latin) letter  V  (also v)  count:    3
(Latin) letter  W  (also w)  count:   16
(Latin) letter  X  (also x)  count:    9
(Latin) letter  Y  (also y)  count:   23
(Latin) letter  Z  (also z)  count:    6

file ───── countfrq.rex ───── has 3186 unique characters.

('02'x  character count:    1
('0F'x  character count:    2
('11'x  character count:    2
('18'x  character count:    1
('19'x  character count:    1
blank  ('20'x  character count: 1041
"  ('22'x  character count:   12
#  ('23'x  character count:    6
%  ('25'x  character count:    1
&  ('26'x  character count:    1
'  ('27'x  character count:   47
(  ('28'x  character count:   21
)  ('29'x  character count:   20
*  ('2A'x  character count:   78
+  ('2B'x  character count:    4
,  ('2C'x  character count:   16
-  ('2D'x  character count:    1
.  ('2E'x  character count:   38
/  ('2F'x  character count:   80
0  ('30'x  character count:    8
1  ('31'x  character count:   10
2  ('32'x  character count:   10
5  ('35'x  character count:    7
6  ('36'x  character count:    2
8  ('38'x  character count:    2
9  ('39'x  character count:    3
:  ('3A'x  character count:    5
;  ('3B'x  character count:    9
<  ('3C'x  character count:    2
=  ('3D'x  character count:   38
?  ('3F'x  character count:    5
@  ('40'x  character count:    9
A  ('41'x  character count:    3
B  ('42'x  character count:    1
C  ('43'x  character count:    8
D  ('44'x  character count:    6
E  ('45'x  character count:    4
F  ('46'x  character count:    1
G  ('47'x  character count:    3
H  ('48'x  character count:    1
I  ('49'x  character count:    8
J  ('4A'x  character count:    2
K  ('4B'x  character count:    2
L  ('4C'x  character count:   22
M  ('4D'x  character count:    2
N  ('4E'x  character count:    3
O  ('4F'x  character count:    1
P  ('50'x  character count:    2
Q  ('51'x  character count:    1
R  ('52'x  character count:    3
S  ('53'x  character count:    1
T  ('54'x  character count:    6
U  ('55'x  character count:    4
V  ('56'x  character count:    1
W  ('57'x  character count:    1
X  ('58'x  character count:    4
Y  ('59'x  character count:    1
Z  ('5A'x  character count:    1
[  ('5B'x  character count:    3
\  ('5C'x  character count:    2
]  ('5D'x  character count:    3
a  ('61'x  character count:  130
b  ('62'x  character count:   22
c  ('63'x  character count:   93
d  ('64'x  character count:   49
e  ('65'x  character count:  172
f  ('66'x  character count:   48
g  ('67'x  character count:   20
h  ('68'x  character count:   72
i  ('69'x  character count:   78
j  ('6A'x  character count:    4
k  ('6B'x  character count:    9
l  ('6C'x  character count:   69
m  ('6D'x  character count:   18
n  ('6E'x  character count:   98
o  ('6F'x  character count:   96
p  ('70'x  character count:   33
q  ('71'x  character count:    3
r  ('72'x  character count:  104
s  ('73'x  character count:   80
t  ('74'x  character count:  158
u  ('75'x  character count:   43
v  ('76'x  character count:    2
w  ('77'x  character count:   15
x  ('78'x  character count:    5
y  ('79'x  character count:   22
z  ('7A'x  character count:    5
{  ('7B'x  character count:    1
|  ('7C'x  character count:    1
}  ('7D'x  character count:    1
~  ('7E'x  character count:   76
ñ  ('A4'x  character count:    1
¿  ('A8'x  character count:    1
¬  ('AA'x  character count:    1
½  ('AB'x  character count:    1
«  ('AE'x  character count:   27
░  ('B0'x  character count:    1
▒  ('B1'x  character count:    1
▓  ('B2'x  character count:    1
─  ('C4'x  character count:   25
█  ('DB'x  character count:    1
α  ('E0'x  character count:    1
ß  ('E1'x  character count:    1
Γ  ('E2'x  character count:    1
π  ('E3'x  character count:    1
Σ  ('E4'x  character count:    1
σ  ('E5'x  character count:    1
µ  ('E6'x  character count:    1
Φ  ('E8'x  character count:    1
Θ  ('E9'x  character count:    1
δ  ('EB'x  character count:    1
∞  ('EC'x  character count:    1
ε  ('EE'x  character count:    1
∙  ('F9'x  character count:    3
·  ('FA'x  character count:    1

☼ end─of─list ☼
```

### Version 2 (for TSO)

`/*REXX program counts the occurences of all characters in a file* Adapted version 1 for TSO (EXECIO instead of linein)* No translation to uppercase takes place* There is no need for tails being hex* 25.07.2012 Walter Pachl***********************************************************************/   Parse arg dsn .                    /*Data set to be processed       */  if dsn='' Then                     /*none specified?                */    dsn='PRIV.V100(TEST)'            /* Use default.                  */  c.=0                               /* Character counts              */  "ALLOC   FI(IN) DA("dsn") SHR REUSE"  'EXECIO   * DISKR IN (STEM L. FINIS'  'FREE   FI(IN)'  totChars=0                         /*count of the total num of chars*/  totLetters=0                       /*count of the total num letters.*/  indent=left('',20)                 /*used for indentation of output.*/   do j=1 to l.0                      /*process all lines              */    rec=l.j                          /*take line number j             */    Say '>'rec'<' length(rec)        /*that's in PRIV.V100(TEST)      */    Say ' E8C44D8FF015674BCDEF'    Say ' 61100711200000000002'    do k=1 for length(rec)           /*loop over characters           */      totChars=totChars+1            /*Increment total number of chars*/      c=substr(rec,k,1)              /*get character number k         */      c.c=c.c+1                      /*increment the character's count*/      End    End                              /*maybe we're ½ done by now, or ¬*/   w=length(totChars)                 /*used for right-aligning counts.*/  say 'file -----' dsn "----- has" j-1 'records.'  say 'file -----' dsn "----- has" totChars 'characters.'   do L=0 to 255                      /* display nonzero letter counts */    c=d2c(l)                         /* the character in question     */    if c.c>0 &,                      /* was found in the file         */       datatype(c,'M')>0 Then Do     /* and is a Latin letter         */      say indent "(Latin) letter " c 'count:' right(c.c,w) /* tell    */      totLetters=totLetters+c.c      /* increment number of letters   */      End    End   say 'file -----' dsn "----- has" totLetters '(Latin) letters.'  say '                           other characters follow'  other=0  do m=0 to 255                      /* now for non-letters           */    c=d2c(m)                         /* the character in question     */    y=c2x(c)                         /* the hex representation        */    if c.c>0 &,                      /* was found in the file         */       datatype(c,'M')=0 Then Do     /* and is not a Latin letter     */      other=other+c.c                /* increment count               */      _=right(c.c,w)                 /* prepare output of count       */      select                         /*make the character viewable.   */       when c<<' ' | m==255 then say indent  "'"y"'x character count:" _       when c==' '          then say indent   "blank character count:" _       otherwise                 say indent "   " c 'character count:' _       end     end   endsay 'file -----' dsn "----- has" other 'other characters.'`

Output:

```>WaA  Pa12 :&-: :äüÖ2< 20
E8C44D8FF015674BCDEF
61100711200000000002
file ----- PRIV.V100(TEST) ----- has 1 records.
file ----- PRIV.V100(TEST) ----- has 20 characters.
(Latin) letter  a count:  2
(Latin) letter  A count:  1
(Latin) letter  P count:  1
(Latin) letter  W count:  1
file ----- PRIV.V100(TEST) ----- has 5 (Latin) letters.
'00'x character count:  1
'10'x character count:  1
blank character count:  3
& character count:  1
- character count:  1
: character count:  1
: character count:  1
ä character count:  1
ü character count:  1
Ö character count:  1
1 character count:  1
2 character count:  2
file ----- PRIV.V100(TEST) ----- has 15 other characters.```

## Ring

` textData = read("C:\Ring\ReadMe.txt")ln =len(textData)charCount = list(255)totCount = 0 for i =1 to ln    char = ascii(substr(textData,i,1))    charCount[char] = charCount[char] + 1    if char > 31 totCount = totCount + 1 oknext for i = 32 to 255    if charCount[i] > 0 see char(i) + " = " + charCount[i] + " " + (charCount[i]/totCount)*100 + " %" + nl oknext `

## Ruby

`def letter_frequency(file)  letters = 'a' .. 'z'  File.read(file) .       split(//) .       group_by {|letter| letter.downcase} .       select   {|key, val| letters.include? key} .       collect  {|key, val| [key, val.length]} end letter_frequency(ARGV[0]).sort_by {|key, val| -val}.each {|pair| p pair}`

example output, using the program file as input:

```\$ ruby letterFrequency.rb letterFrequency.rb
["e", 34]
["l", 20]
["t", 17]
["r", 14]
["a", 12]
["y", 9]
["c", 8]
["i", 7]
["v", 6]
["n", 6]
["f", 6]
["s", 6]
["d", 5]
["p", 5]
["k", 5]
["u", 4]
["o", 4]
["g", 3]
["b", 2]
["h", 2]
["q", 2]
["z", 1]
["w", 1]```

### Ruby 2.0

`def letter_frequency(file)  freq = Hash.new(0)  file.each_char.lazy.grep(/[[:alpha:]]/).map(&:upcase).each_with_object(freq) do |char, freq_map|    freq_map[char] += 1  endend letter_frequency(ARGF).sort.each do |letter, frequency|  puts "#{letter}: #{frequency}"end`

note that this version *should* use less memory, even on a gigantic file. This is done by using lazy enumerables, which ruby 2.0 introduces.

example output, using the (somewhat large) dictionary file as the input. Also note that this versions works on unicode text.

```\$ ruby letter_frequency.rb /usr/share/dict/words
A: 64439
B: 15526
C: 31872
D: 28531
E: 88833
F: 10675
G: 22712
H: 19320
I: 66986
J: 1948
K: 8409
L: 41107
M: 22508
N: 57144
O: 48944
P: 22274
Q: 1524
R: 57347
S: 90113
T: 53006
U: 26118
V: 7989
W: 7530
X: 2124
Y: 12652
Z: 3281
Å: 1
á: 10
â: 6
ä: 7
å: 3
ç: 5
è: 28
é: 144
ê: 6
í: 2
ñ: 8
ó: 8
ô: 2
ö: 16
û: 3
ü: 12
```

## Run BASIC

`open "c:\rbp101\public\textFile.txt" for input as #ftextData\$ = input\$(#f, lof( #f))ln =len(textData\$)close #f dim charCount( 255) for i =1 to ln   char            = asc(mid\$(textData\$,i,1))   charCount(char) = charCount(char) + 1   if char > 31 then totCount = totCount + 1next i for i = 32 to 255if charCount(i) > 0 then print "Ascii:";using("###",i);" char:";chr\$(i);" Count:";using("#######",charCount(i));" ";using("##.#",(charCount(i) / totCount) * 100);"%"next i`

Output uses this program to count itself:

```Ascii: 32 char:  Count:     76 16.1%
Ascii: 34 char:" Count:     18  3.8%
Ascii: 35 char:# Count:     17  3.6%
Ascii: 36 char:\$ Count:      6  1.3%
Ascii: 37 char:% Count:      1  0.2%
Ascii: 40 char:( Count:     16  3.4%
Ascii: 41 char:) Count:     16  3.4%
Ascii: 42 char:* Count:      1  0.2%
Ascii: 43 char:+ Count:      2  0.4%
Ascii: 44 char:, Count:      6  1.3%
Ascii: 46 char:. Count:      2  0.4%
Ascii: 47 char:/ Count:      1  0.2%
Ascii: 48 char:0 Count:      4  0.8%
Ascii: 49 char:1 Count:      8  1.7%
Ascii: 50 char:2 Count:      3  0.6%
Ascii: 51 char:3 Count:      2  0.4%
Ascii: 53 char:5 Count:      4  0.8%
Ascii: 58 char:: Count:      4  0.8%
Ascii: 59 char:; Count:      8  1.7%
Ascii: 61 char:= Count:      7  1.5%
Ascii: 62 char:> Count:      2  0.4%
Ascii: 65 char:A Count:      1  0.2%
Ascii: 67 char:C Count:     10  2.1%
Ascii: 68 char:D Count:      3  0.6%
Ascii: 70 char:F Count:      1  0.2%
Ascii: 92 char:\ Count:      3  0.6%
Ascii: 97 char:a Count:     19  4.0%
Ascii: 98 char:b Count:      2  0.4%
Ascii: 99 char:c Count:     17  3.6%
Ascii:100 char:d Count:      3  0.6%
Ascii:101 char:e Count:     13  2.7%
Ascii:102 char:f Count:     10  2.1%
Ascii:103 char:g Count:      3  0.6%
Ascii:104 char:h Count:     14  3.0%
Ascii:105 char:i Count:     24  5.1%
Ascii:108 char:l Count:      7  1.5%
Ascii:109 char:m Count:      2  0.4%
Ascii:110 char:n Count:     25  5.3%
Ascii:111 char:o Count:     21  4.4%
Ascii:112 char:p Count:      6  1.3%
Ascii:114 char:r Count:     17  3.6%
Ascii:115 char:s Count:      7  1.5%
Ascii:116 char:t Count:     38  8.0%
Ascii:117 char:u Count:     16  3.4%
Ascii:120 char:x Count:      7  1.5%
```

## Rust

Works with all UTF-8 characters

`use std::collections::btree_map::BTreeMap;use std::{env, process};use std::io::{self, Read, Write};use std::fmt::Display;use std::fs::File; fn main() {    let filename = env::args().nth(1)        .ok_or("Please supply a file name")        .unwrap_or_else(|e| exit_err(e, 1));     let mut buf = String::new();    let mut count = BTreeMap::new();     File::open(&filename)        .unwrap_or_else(|e| exit_err(e, 2))        .read_to_string(&mut buf)        .unwrap_or_else(|e| exit_err(e, 3));      for c in buf.chars() {        *count.entry(c).or_insert(0) += 1;    }     println!("Number of occurences per character");    for (ch, count) in &count {        println!("{:?}: {}", ch, count);    }} #[inline]fn exit_err<T>(msg: T, code: i32) -> ! where T: Display {    writeln!(&mut io::stderr(), "{}", msg).expect("Could not write to stderr");    process::exit(code)}`

Output when run on source file:

```Number of occurences per character
'\n': 35
' ': 167
'!': 4
'\"': 10
'#': 1
'&': 4
'(': 25
')': 25
'*': 1
'+': 1
',': 12
'-': 1
'.': 10
'0': 1
'1': 3
'2': 2
'3': 2
':': 37
';': 13
'<': 1
'=': 4
'>': 2
'?': 1
'B': 2
'C': 1
'D': 2
'F': 2
'M': 2
'N': 1
'P': 1
'R': 1
'S': 1
'T': 5
'W': 1
'[': 1
']': 1
'_': 15
'a': 20
'b': 5
'c': 22
'd': 12
'e': 75
'f': 14
'g': 5
'h': 6
'i': 29
'k': 1
'l': 23
'm': 13
'n': 36
'o': 28
'p': 17
'r': 45
's': 33
't': 42
'u': 24
'v': 2
'w': 8
'x': 6
'y': 4
'{': 9
'|': 6
'}': 9
```

## Scala

`import io.Source.fromFile def letterFrequencies(filename: String) =   fromFile(filename).mkString groupBy (c => c) mapValues (_.length)`

## Scheme

Using guile scheme 2.0.11.

Note that this prints the scheme representations of characters in no particular order.

`(use-modules (ice-9 format)) (define (char-freq port table)  (if   (eof-object? (peek-char port))   table   (char-freq port (add-char (read-char port) table)))) (define (add-char char table)  (cond   ((null? table) (list (list char 1)))   ((eq? (caar table) char) (cons (list char (+ (cadar table) 1)) (cdr table)))   (#t (cons (car table) (add-char char (cdr table)))))) (define (format-table table)  (for-each (lambda (t) (format #t "~10s~10d~%" (car t) (cadr t))) table)) (define (print-freq filename)  (format-table (char-freq (open-input-file filename) '()))) (print-freq "letter-frequency.scm")`

```#\(               45
#\u                5
#\s                9
#\e               47
#\-               19
#\m                9
#\o               16
#\d               19
#\l               25
#\space           83
#\i               15
#\c               28
#\9                1
#\f               20
#\r               39
#\a               47
#\t               36
#\)               45
#\newline         21
#\n               15
#\h               14
#\q                7
#\p                9
#\b               16
#\j                1
#\?                3
#\k                1
#\1                4
#\+                1
#\#                2
#\"                4
#\~                3
#\0                2
#\%                1
#\'                1
#\y                1
#\.                1
```

An implementation for CHICKEN scheme:

` (with-input-from-string "foobar"  (lambda ()    (port-fold (lambda (x s)                 (alist-update x                               (add1 (alist-ref x s eq? 0))                               s))               '()               read-char))) `

which shows: ((#\f . 1) (#\o . 2) (#\b . 1) (#\a . 1) (#\r . 1))

## Seed7

`\$ include "seed7_05.s7i"; const type: charHash is hash [char] integer; const proc: main is func  local    var charHash: numberOfChars is charHash.EMPTY_HASH;    var char: ch is ' ';  begin    ch := getc(IN);    while ch <> EOF do      if ch in numberOfChars then        incr(numberOfChars[ch]);      else        numberOfChars @:= [ch] 1;      end if;      ch := getc(IN);    end while;    for ch range sort(keys(numberOfChars)) do      writeln(ch <& " " <& numberOfChars[ch]);    end for;  end func;`

Output when the program uses itself as input:

``` 22
129
" 4
\$ 1
& 2
' 2
( 6
) 6
. 2
0 1
...
s 21
t 9
u 9
v 2
w 3
y 2```

## Sidef

`func letter_frequency(File file) {    file.read.chars.grep{.match(/[[:alpha:]]/)} \        .group_by {|letter| letter.downcase}    \        .map_val  {|_, val| val.len}            \        .sort_by  {|_, val| -val}} var top = letter_frequency(File(__FILE__))top.each{|pair| say "#{pair[0]}: #{pair[1]}"}`
Output:
```e: 22
l: 17
a: 16
t: 14
r: 14
p: 12
f: 8
i: 8
n: 7
c: 6
u: 6
o: 6
v: 6
y: 5
s: 5
h: 3
w: 2
q: 2
b: 2
m: 2
g: 2
d: 1
```

## SIMPOL

Example: open a text file and compute letter frequency.

`constant iBUFSIZE 500 function main(string filename)  fsfileinputstream fpi  integer e, i, aval, zval, cval  string s, buf, c  array chars   e = 0  fpi [email protected] fsfileinputstream.new(filename, error=e)  if fpi [email protected]= .nul    s = "Error, file """ + filename + """ not found{d}{a}"  else    chars [email protected] array.new()    aval = .charval("a")    zval = .charval("z")    i = 1    while i <= 26      chars[i] = 0      i = i + 1    end while    buf = .lcase(fpi.getstring(iBUFSIZE, 1))    while not fpi.endofdata and buf > ""      i = 1      while i <= .len(buf)        c = .substr(buf, i, 1)        cval = .charval(c)        if cval >= aval and cval <= zval          chars[cval - aval + 1] = chars[cval - aval + 1] + 1        end if        i = i + 1      end while      buf = .lcase(fpi.getstring(iBUFSIZE, 1))    end while     s = "Character counts for """ + filename + """{d}{a}"    i = 1    while i <= chars.count()      s = s + .char(aval + i - 1) + ": " + .tostr(chars[i], 10) + "{d}{a}"      i = i + 1    end while  end ifend function s`

As this was being created I realized that in [SIMPOL] I wouldn't have done it this way (in fact, I wrote it differently the first time and had to go back and change it to use an array afterward). In [SIMPOL] we would have used the set object. It acts similarly to a single-dimensional array, but can also use various set operations, such as difference, unite, intersect, etc. One of th einteresting things is that each unique value is stored only once, and the number of duplicates is stored with it. The sample then looks a little cleaner:

`constant iBUFSIZE 500 function main(string filename)  fsfileinputstream fpi  integer e, i, aval, zval  string s, buf, c  set chars   e = 0  fpi [email protected] fsfileinputstream.new(filename, error=e)  if fpi [email protected]= .nul    s = "Error, file """ + filename + """ not found{d}{a}"  else    chars [email protected] set.new()    aval = .charval("a")    zval = .charval("z")    buf = .lcase(fpi.getstring(iBUFSIZE, 1))    while not fpi.endofdata and buf > ""      i = 1      while i <= .len(buf)        c = .substr(buf, i, 1)        if .charval(c) >= aval and .charval(c) <= zval          chars.addvalue(c)        end if        i = i + 1      end while      buf = .lcase(fpi.getstring(iBUFSIZE, 1))    end while     s = "Character counts for """ + filename + """{d}{a}"    i = 1    while i <= chars.count()      s = s + chars[i] + ": " + .tostr(chars.valuecount(chars[i]), 10) + "{d}{a}"      i = i + 1    end while  end ifend function s`

The final stage simply reads the totals for each character. One caveat, if a character is unrepresented, then it will not show up at all in this second implementation.

## Swift

`import Foundation let dictPath: String switch CommandLine.arguments.count {case 2:  dictPath = CommandLine.arguments[1]case _:  dictPath = "/usr/share/dict/words"} let wordsData = FileManager.default.contents(atPath: dictPath)!let allWords = String(data: wordsData, encoding: .utf8)!let words = allWords.components(separatedBy: "\n")let counts = words.flatMap({ \$0.map({ (\$0, 1) }) }).reduce(into: [:], { \$0[\$1.0, default: 0] += \$1.1 }) for (char, count) in counts {  print("\(char): \(count)")}`

## Tcl

`proc letterHistogram {fileName} {    # Initialize table (in case of short texts without every letter)    for {set i 97} {\$i<=122} {incr i} {        set frequency([format %c \$i]) 0    }    # Iterate over characters in file    set f [open \$fileName]    foreach c [split [read \$f] ""] {        # Count them if they're alphabetic        if {[string is alpha \$c]} {            incr frequency([string tolower \$c])        }    }    close \$f    # Print the histogram    parray frequency} letterHistogram the/sample.txt`

## TUSCRIPT

` \$\$ MODE TUSCRIPTwords = REQUEST ("http://www.puzzlers.org/pub/wordlists/unixdict.txt") DICT letters createMODE {}COMPILELOOP word=words letters=SPLIT (word,|":?:") LOOP letter=letters  DICT letters ADD/QUIET/COUNT letter ENDLOOPENDLOOPENDCOMPILEDICT letters unload letter,size,cnt index    =DIGIT_INDEX (cnt)index    =REVERSE (index)letter   =INDEX_SORT (letter,index)cnt      =INDEX_SORT (cnt,index)frequency=JOIN (letter," --- ",cnt) *{frequency} `

Output:

```e --- 20144
a --- 16421
i --- 13980
r --- 13436
t --- 12836
o --- 12738
n --- 12097
s --- 10210
l --- 10061
c --- 8216
u --- 6489
m --- 5828
d --- 5799
p --- 5516
h --- 5208
g --- 4129
b --- 4115
y --- 3633
f --- 2662
w --- 1968
k --- 1925
v --- 1902
x --- 617
z --- 433
j --- 430
q --- 378
' --- 105
. --- 6
& --- 6
1 --- 2
9 --- 1
8 --- 1
7 --- 1
6 --- 1
5 --- 1
4 --- 1
3 --- 1
2 --- 1
0 --- 1
```

## TXR

### TXR Extraction Language plus TXR Lisp

`@(do (defvar h (hash :equal-based)))@(repeat)@(coll :vars ())@\  @{letter /[A-Za-z]/}@(filter :upcase letter)@\  @(do (inc [h letter 0]))@\@(end)@(end)@(do (dohash (key value h)       (format t "~a: ~a\n" key value)))`
Output:
```\$ ./txr letterfreq.txr /usr/share/dict/words
A: 64123
B: 15524
C: 31569
[ ... abridged ... ]
X: 2124
Y: 12507
Z: 3238```

### TXR Lisp

`(let* ((s (open-file "/usr/share/dict/words" "r"))       (chrs [keep-if* chr-isalpha (gun (get-char s))])       (h [group-reduce (hash) chr-toupper (op succ @1) chrs 0]))  (dohash (key value h)    (put-line `@key: @value`)))`

## Vala

Library: Gee

Counts every character except new line character.

` using Gee; void main(string[] args){    string filename = args[1];    var file = FileStream.open(filename, "r");     var	counter	= new HashMap<char, int>();     string line = file.read_line();    while (line != null){        for (int x = 0;	x < line.length; x++){            counter[line[x]] = counter[line[x]] + 1;	}        line = file.read_line();    }     foreach (var elem in counter.entries){	stdout.printf("%c occured %d times\n", elem.key, elem.value);    }} `

Sample output (run on its own source code) with several lines omitted:

```v occured 5 times
, occured 4 times
w occured 2 times
occured 19 times
S occured 1 times
1 occured 2 times
! occured 1 times
k occured 1 times
l occured 22 times
```

## VBA

` Public Sub LetterFrequency(fname)'count number of letters in text file "fname" (ASCII-coded)'note: we count all characters but print only the letter frequencies Dim Freqs(255) As LongDim abyte As ByteDim ascal as Byte 'ascii code for lowercase aDim ascau as Byte 'ascii code for uppercase a 'try to open the fileOn Error GoTo CantOpenOpen fname For Input As #1On Error GoTo 0 'initializeFor i = 0 To 255  Freqs(i) = 0Next i 'process file byte-per-byteWhile Not EOF(1) abyte = Asc(Input(1, #1)) Freqs(abyte) = Freqs(abyte) + 1WendClose #1 'add lower and upper case together and print resultDebug.Print "Frequencies:"ascal = Asc("a")ascau = Asc("A")For i = 0 To 25  Debug.Print Chr\$(ascal + i), Freqs(ascal + i) + Freqs(ascau + i)Next iExit Sub CantOpen:  Debug.Print "can't find or read the file "; fname  CloseEnd Sub `

Output:

```LetterFrequency "d:\largetext.txt"
Frequencies:
a              24102
b              4985
c              4551
d              19127
e              61276
f              2734
g              10661
h              8243
i              21589
j              4904
k              7186
l              12026
m              7454
n              31963
o              19021
p              4960
q              37
r              21166
s              13403
t              21090
u              6117
v              8612
w              5017
x              168
y              299
z              4159
```

## VBScript

` filepath = "SPECIFY FILE PATH HERE" Set objfso = CreateObject("Scripting.FileSystemObject")Set objdict = CreateObject("Scripting.Dictionary")Set objfile = objfso.OpenTextFile(filepath,1) txt = objfile.ReadAll For i = 1 To Len(txt)	char = Mid(txt,i,1)	If objdict.Exists(char) Then		objdict.Item(char) = objdict.Item(char) + 1	Else		objdict.Add char,1	End IfNext For Each key In objdict.Keys	WScript.StdOut.WriteLine key & " = " & objdict.Item(key)Next	 objfile.CloseSet objfso = NothingSet objdict = Nothing `

## Vedit macro language

`File_Open("c:\txt\a_text_file.txt")Update() for (#1='A'; #1<='Z'; #1++) {    Out_Reg(103) Char_Dump(#1,NOCR) Out_Reg(CLEAR)    #2 = Search(@103, BEGIN+ALL+NOERR)    Message(@103) Num_Type(#2)}`

Example output:

```A   76
B   23
C   51
D   64
E  192
F   51
G   32
H   59
I  146
J    1
K    9
L   73
M   34
N   94
O  113
P   27
Q    1
R   92
S   89
T  138
U   63
V   26
W   35
X   16
Y   16
Z    2
```

## Whitespace

`   							           		    		  	  		 	        	      		 			  		 	   			   		   		   	    	 	  	   		   		        	       	  		  	    				  		  	     	     	    				 	   	 	 	    		    	      `
`push 127; Initialize a slot in the heap for each ASCII character.0:    dup    push 0    store    push 1    sub    dup    jn 1    jump 0; Read until EOF, incrementing the relevant heap slot.1:    push 0    dup    ichr    load    dup    jn 2 ; Done reading, proceed to print.    dup    load    push 1    add    store    jump 1; Stack is [-1 -1], but [0] would be nice.2:    sub; Print characters with tallies greater than 0.3:    push 1    add    dup    push 128    sub    jz 4 ; All done.    dup    load    jz 3 ; Don't print if no occurrences.    dup    ochr ; Display the character,    push 32    ochr ; a space,    dup    load    onum ; its frequency,    push 10    ochr ; and a newline.    jump 34:    pop    exit`
Output:
```\$ cat freq.ws | wspace freq.ws
64

55
119```

## XPL0

This takes advantage of DOS's ability to redirect input from a file to the keyboard. The input file must be terminated with an end-of-file character (\$1A). Usage: count <filename.ext

`include c:\cxpl\codes;          \intrinsic 'code' declarationsint A(256), C, I;[for C:= 0 to 256-1 do A(C):= 0;repeat  C:= ChIn(1);            \device 1 doesn't buffer nor echo chars        A(C):= A(C)+1;          \count characteruntil   C=\EOF\\$1A;C:= 0;for I:= 0 to 128-1 do           \only show 7-bit ASCII        [ChOut(0, \tab\9);        case C of          \$0A: ChOut(6, \$19);   \line feed = down arrow          \$0D: ChOut(6, \$1B)    \carriage return = left arrow        other  ChOut(6, C);     \all other characters display on device 6        ChOut(0, ^ );        IntOut(0, A(C));        \show count        C:= C+16;               \columnar order        if (I&7) = 7 then [CrLf(0);  C:= C-8*16+1];        ];]`

Example output of count.xpl counting itself:

## Yabasic

`dim ascCodes(255) f = open("unixdict.txt", "r") if f then    while(not eof(#f))         line input #f a\$        for i = 1 to len(a\$)            c = asc(mid\$(a\$, i, 1))            ascCodes(c) = ascCodes(c) + 1        next    wend    for i = 1 to 255        c = ascCodes(i)        if c print chr\$(i), " = ", c    next    close #fend if`

## zkl

`fcn ccnt(textInBitBucket){   letters:=["a".."z"].pump(List().write,0); // array of 26 zeros   textInBitBucket.howza(0).pump(Void,'wrap(c){  // pump text as ints      if(97<=c<=122)     c-=97;      else if(65<=c<=90) c-=65;      else return(Void.Skip);      letters[c]+=1   });   sum:=letters.sum(); println(sum," letters");   letters.enumerate().pump(List,'wrap([(c,n)]){      "%s(%d:%d%)".fmt((c+65).toChar(),n,n*100/sum)})   .concat(",").println();} ccnt(Data(0,Int,"This is a test"));ccnt(File("dict.txt").read());`
Output:
```11 letters
A(1:9%),B(0:0%),C(0:0%),D(0:0%),E(1:9%),F(0:0%),G(0:0%),H(1:9%),I(2:18%),J(0:0%),K(0:0%),L(0:0%),M(0:0%),N(0:0%),O(0:0%),P(0:0%),Q(0:0%),R(0:0%),S(3:27%),T(3:27%),U(0:0%),V(0:0%),W(0:0%),X(0:0%),Y(0:0%),Z(0:0%)

181171 letters
A(16421:9%),B(4115:2%),C(8216:4%),D(5799:3%),E(20144:11%),F(2662:1%),G(4129:2%),H(5208:2%),I(13980:7%),J(430:0%),K(1925:1%),L(10061:5%),M(5828:3%),N(12097:6%),O(12738:7%),P(5516:3%),Q(378:0%),R(13436:7%),S(10210:5%),T(12836:7%),U(6489:3%),V(1902:1%),W(1968:1%),X(617:0%),Y(3633:2%),Z(433:0%)
```