Walk a directory/Non-recursively: Difference between revisions

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Latest revision as of 11:31, 16 February 2024

Task

Walk a given directory and print the names of files matching a given pattern.

(How is "pattern" defined? substring match? DOS pattern? BASH pattern? ZSH pattern? Perl regular expression?)

Note: This task is for non-recursive methods. These tasks should read a single directory, not an entire directory tree.

Note: Please be careful when running any code presented here.

Related task

Walk Directory Tree (read entire directory tree).

11l

Translation of: Python

L(filename) fs:list_dir(‘/foo/bar’)
   I filename.ends_with(‘.mp3’)
      print(filename)

68000 Assembly

Non-recursive directory walk in Motorola 68000 assembly language under AmigaOs 2.04+ by Thorham. Uses regular Amiga dos pattern matching.

;
; Non-recursive directory walk for Motorola 68000 under AmigaOs 2.04+ by Thorham
;

execBase equ 4

;
; from exec includes
;
_LVOOpenLibrary equ -552
_LVOCloseLibrary equ -414
_LVOAllocVec equ -684
_LVOFreeVec equ -690

MEMF_ANY equ 0

;
; from dos includes
;
_LVOVPrintf equ -954
_LVOExamine equ -102
_LVOExNext equ -108
_LVOLock equ -84
_LVOUnLock equ -90
_LVOParsePatternNoCase equ -966
_LVOMatchPatternNoCase equ -972

ACCESS_READ equ -2
                    rsset   0
fib_DiskKey         rs.l    1
fib_DirEntryType    rs.l    1
fib_FileName        rs.b    108
fib_Protection      rs.l    1
fib_EntryType       rs.l    1
fib_Size            rs.l    1
fib_NumBlocks       rs.l    1
fib_DateStamp       rs.b    12
fib_Comment         rs.b    80
fib_OwnerUID        rs.w    1
fib_OwnerGID        rs.w    1
fib_Reserved        rs.b    32
fib_SIZEOF          rs.b    0

;
; main
;

start
    move.l  execBase,a6

; open dos.library

    lea     dosName,a1
    moveq   #37,d0
    jsr     _LVOOpenLibrary(a6)
    move.l  d0,dosBase
    beq     exit

; allocate memory for file info block

    move.l  #fib_SIZEOF,d0
    move.l  #MEMF_ANY,d1
    jsr     _LVOAllocVec(a6)
    move.l  d0,fib
    beq     exit

; get directory lock

    move.l  dosBase,a6

    move.l  #pathString,d1
    move.l  #ACCESS_READ,d2
    jsr     _LVOLock(a6)
    move.l  d0,lock
    beq     exit

; examine directory for ExNext

    move.l  lock,d1
    move.l  fib,d2
    jsr     _LVOExamine(a6)
    tst.w   d0
    beq     exit

; parse pattern string

    move.l  #patternString,d1
    move.l  #patternParsed,d2
    move.l  #sizeof_patternString*2+2,d3
    jsr     _LVOParsePatternNoCase(a6)
    tst.l   d0
    blt     exit

; get some pointers for use in the loop

    lea     printfArgs,a2
    move.l  fib,a3
    lea     fib_FileName(a3),a3

.loop

; get next directory entry

    move.l  lock,d1
    move.l  fib,d2
    jsr     _LVOExNext(a6)
    tst.w   d0
    beq     exit

; match pattern

    move.l  #patternParsed,d1
    move.l  a3,d2
    jsr     _LVOMatchPatternNoCase(a6)

; if match then print file name

    tst.l   d0
    beq     .nomatch

    move.l  a3,(a2)
    move.l  #formatString,d1
    move.l  #printfArgs,d2
    jsr     _LVOVPrintf(a6)

.nomatch
    bra     .loop

; cleanup and exit

exit
    move.l  dosBase,a6
    move.l  lock,d1
    jsr     _LVOUnLock(a6)

    move.l  execBase,a6
    move.l  fib,a1
    tst.l   a1
    beq     .l1
    jsr     _LVOFreeVec(a6)
.l1
    move.l  dosBase,a1
    jsr     _LVOCloseLibrary(a6)
    rts

    section data,data_p
;
; variables
;
dosBase
    dc.l    0

lock
    dc.l    0

fib
    dc.l    0

printfArgs
    dc.l    0
;
; strings
;
dosName
    dc.b    "dos.library",0

pathString
    dc.b    "ram:",0

formatString
    dc.b    "%s",10,0

patternString
    dc.b    "#?",0
patternString_end
sizeof_patternString=patternString_end-patternString

patternParsed
    dcb.b   sizeof_patternString*2+2

This program runs under CP/M, which was the commonly used OS on 8080 (and Z80)-based machines. The pattern used is the CP/M file pattern, which is the same as a DOS pattern: the filename, the extension, and an optional drive letter.

exit:	equ	0	; CP/M syscall to exit
puts:	equ	9	; CP/M syscall to print a string
sfirst:	equ	17	; 'Find First' CP/M syscall
snext:	equ	18	; 'Find Next' CP/M syscall
FCB:	equ	5Ch	; Location of FCB for file given on command line
	org	100h	
	lxi	d,FCB	; CP/M parses the command line for us automatically
	mvi	c,sfirst; and prepares an FCB which we can pass to SFIRST
	call	5	; immediately.
	lxi	d,emsg	; If SFIRST returns an error, there is no file,
	mvi	c,puts	; so we should print an error message.
loop:	inr	a	; A=FF = error
	jz	5
	dcr	a	; If we _do_ have a file, the directory entry
	rrc		; is located at DTA (80h) + A * 32. 0<=A<=3. 
	rrc		; Rotate right twice, moving low bits into high bits,
	stc		; then finally rotate a 1 bit into the top bit.
	rar		; The effect is 000000AB -> 1AB00000.
	inr	a	; Finally the filename is at offset 1 in the dirent.
	mvi	h,0	; Set HL = pointer to the filename
	mov	l,a	
	lxi	d,fname	; The filename is stored as 'FILENAMEEXT', but let's
	mvi	b,8	; be nice and print 'FILENAME.EXT\r\n'.
	call	memcpy	; Copy filename (wihtout extension) into placeholder
	inx	d	; Skip the '.' in the placeholder
	mvi	b,3	; Then copy the extension
	call	memcpy
	lxi	d,fname	; Then print the formatted filename
	mvi	c,puts
	call	5
	lxi	d,FCB	; Find the next file matching the pattern in the FCB
	mvi	c,snext ; The result is the same as for SFIRST, so we can
	call	5	; loop back here, except FF means no more files.
	mvi	c,exit	; Arrange for the error routine to instead exit cleanly
	jmp	loop
memcpy:	mov	a,m	; Copy B bytes from HL to DE
	stax	d
	inx	h
	inx	d
	dcr 	b
	jnz	memcpy
	ret	
emsg:	db	'Not Found$'
fname:	db	'XXXXXXXX.XXX',13,10,'$'	; Filename placeholder

Output:

I>dir
I: TINST    COM : TINST    DTA : TINST    MSG : TURBO    COM
I: TURBO    MSG : TURBO    OVR : WALKDIR  ASM : WALKDIR  PRN
I: WALKDIR  HEX : WALKDIR  COM
I>walkdir walkdir.*
WALKDIR .ASM
WALKDIR .PRN
WALKDIR .HEX
WALKDIR .COM

I>walkdir *.com
TINST   .COM
TURBO   .COM
WALKDIR .COM

I>walkdir foobar.baz
Not Found
I>dir a:*.asm
A: COUNT    ASM : DETECT   ASM : SUBLEQ   ASM : LUHN     ASM
I>walkdir a:*.asm
COUNT   .ASM
DETECT  .ASM
SUBLEQ  .ASM
LUHN    .ASM

8th

"*.c" f:glob \ puts an array of strings with the file names on the top of the stack

Action!

The attached result has been obtained under DOS 2.5.

PROC GetFileName(CHAR ARRAY line,fname)
  BYTE i,len

  len=0
  i=3
  FOR i=3 TO 10
  DO
    IF line(i)=32 THEN EXIT FI
    len==+1
    fname(len)=line(i)
  OD
  len==+1
  fname(len)='.
  FOR i=11 TO 13
  DO
    IF line(i)=32 THEN EXIT FI
    len==+1
    fname(len)=line(i)
  OD
  fname(0)=len
RETURN

PROC Dir(CHAR ARRAY filter)
  CHAR ARRAY line(255),fname(255)
  BYTE dev=[1]

  PrintE(filter)
  Close(dev)
  Open(dev,filter,6)
  DO
    InputSD(dev,line)
    IF line(0)=0 OR line(0)>0 AND line(1)#32 THEN
      EXIT
    FI
    GetFileName(line,fname)
    Put(32) PrintE(fname)
  OD
  Close(dev)
  PutE()
RETURN

PROC Main()
  Dir("D:*.*")
  Dir("H1:X*.*")
  Dir("H1:?????.ACT")
  Dir("H1:??F*.*")
RETURN

Output:

Screenshot from Atari 8-bit computer

D:*.*
 DOS.SYS
 DUP.SYS
 INPUT.TXT

H1:X*.*
 XIAOL_24.ACT
 XML_O_CU.ACT

H1:?????.ACT
 AB_3D.ACT
 BREAK.ACT
 CUSIP.ACT
 SIEVE.ACT
 SLEEP.ACT
 WHILE.ACT

H1:??F*.*
 HOFST_34.ACT
 INFINITE.ACT
 UTF8__P2.ACT

Ada

Works with: GCC version 4.12

with Ada.Directories; use Ada.Directories;
with Ada.Text_IO; use Ada.Text_IO;

procedure Walk_Directory
            (Directory : in String := ".";
             Pattern   : in String := "") -- empty pattern = all file names/subdirectory names
is
   Search  : Search_Type;
   Dir_Ent : Directory_Entry_Type;
begin
   Start_Search (Search, Directory, Pattern);

   while More_Entries (Search) loop
      Get_Next_Entry (Search, Dir_Ent);
      Put_Line (Simple_Name (Dir_Ent));
   end loop;

   End_Search (Search);
end Walk_Directory;

ALGOL 68

Works with: ALGOL 68G version Any - tested with release mk15-0.8b.fc9.i386 - uses non-standard library routines get directory and grep in string.

INT match=0, no match=1, out of memory error=2, other error=3;

[]STRING directory = get directory(".");
FOR file index TO UPB directory DO
  STRING file = directory[file index];
  IF grep in string("[Ss]ort*.[.]a68$", file, NIL, NIL) = match THEN
    print((file, new line))
  FI
OD

Sample output:

Quick_sort.a68
Shell_sort.a68
Cocktail_Sort.a68
Selection_Sort.a68
Merge_sort.a68
Bobosort.a68
Insertion_Sort.a68
Permutation_Sort.a68

AppleScript

AppleScript itself has limited built-in file system access. Typically, the Mac OS Finder is used to gather such information. To list all file/folders in the root directory:

tell application "Finder" to return name of every item in (startup disk)
--> EXAMPLE RESULT: {"Applications", "Developer", "Library", "System", "Users"}

To list all pdf files in user's home directory:

tell application "Finder" to return name of every item in (path to documents folder from user domain) whose name ends with "pdf"
--> EXAMPLE RESULT: {"About Stacks.pdf", "Test.pdf"}

The key clause is the whose modifier keyword. The Finder can interpret many variations, including such terms as whose name begins with, whose name contains, etc. As well as boolean combinations:

tell application "Finder" to return name of every item in (path to documents folder from user domain) whose name does not contain "about" and name ends with "pdf"
--> RETURNS: {"Test.pdf"}

The Finder also supports the entire contents modifier keyword, which effectively performs a recursive directory scan without recursion.

tell application "Finder" to return name of every item in entire contents of (path to documents folder from user domain) whose name ends with "pdf"

Nowadays, it's more usual to use macOS's System Events application for this kind of task as it's very much faster than the Finder, especially with 'whose' filters. However, its results, unlike the Finder's, aren't sorted by the items' names and it includes results for hidden items too if these match the criteria.

tell application "System Events" to return name of every item in documents folder whose name extension is "pdf"
--> EXAMPLE RESULT: {"ShellScripting.pdf", "RFC 4180 (CSV spec).pdf", "About Stacks.pdf", "AppleScriptLanguageGuide.pdf", "robinson_jeffers_2004_9.pdf", "DiskWarrior Manual.pdf", "RFC 2445 (iCalendar spec).pdf", "Artistic Orchestration.pdf"}

Intermediate in speed between the Finder and System Events are shell scripts, which are handy if you're more comfortable with shell scripts than with AppleScript.

set docsFolderPath to POSIX path of (path to documents folder)
-- By default, "ls" returns file names sorted by character code, so save the sorting until the end and do it case-insensitively.
set shellCommandText to "ls -f " & quoted form of docsFolderPath & " | grep -i '\\.pdf$' | sort -f"
return paragraphs of (do shell script shellCommandText)
--> EXAMPLE RESULT: {"About Stacks.pdf", "AppleScriptLanguageGuide.pdf", "Artistic Orchestration.pdf", "DiskWarrior Manual.pdf", "RFC 2445 (iCalendar spec).pdf", "RFC 4180 (CSV spec).pdf", "robinson_jeffers_2004_9.pdf", "ShellScripting.pdf"}

Best of all for speed and sorting, although requiring somewhat more code, are the Foundation methods available through AppleScriptObjC.

use AppleScript version "2.4" -- OS X 10.10 (Yosemite) or later
use framework "Foundation"
use scripting additions

set docsFolderURL to current application's class "NSURL"'s fileURLWithPath:(POSIX path of (path to documents folder))
-- Get NSURLs for the folder's visible contents.
tell current application's class "NSFileManager"'s defaultManager() to ¬
    set visibleItems to its contentsOfDirectoryAtURL:(docsFolderURL) includingPropertiesForKeys:({}) ¬
        options:(current application's NSDirectoryEnumerationSkipsHiddenFiles) |error|:(missing value)
-- Filter case-insensitively for those whose names have ".pdf" extensions.
set filter to current application's class "NSPredicate"'s predicateWithFormat:("pathExtension ==[c] 'pdf'")
set PDFs to visibleItems's filteredArrayUsingPredicate:(filter)
-- Get the names of any matching items.
set pdfNames to PDFs's valueForKey:("lastPathComponent")
-- Sort these case-insensitively and considering numerics.
set pdfNames to pdfNames's sortedArrayUsingSelector:("localizedStandardCompare:")
-- Return the result as an AppleScript list of text.
return pdfNames as list
--> EXAMPLE RESULT: {"About Stacks.pdf", "AppleScriptLanguageGuide.pdf", "Artistic Orchestration.pdf", "DiskWarrior Manual.pdf", "RFC 2445 (iCalendar spec).pdf", "RFC 4180 (CSV spec).pdf", "robinson_jeffers_2004_9.pdf", "ShellScripting.pdf"}

Arturo

; list all files at current path
print list "."

; get all files at given path
; and select only the ones we want

; just select the files with .md extension
select list "some/path" 
    => [".md" = extract.extension]

; just select the files that contain "test"
select list "some/path" 
    => [in? "test"]

AutoHotkey

Display all INI files in Windows directory.

Loop, %A_WinDir%\*.ini
 out .= A_LoopFileName "`n"
MsgBox,% out

BaCon

This code will print all files in the current directory ".", separated by a newline symbol:

PRINT WALK$(".", 1, ".+", FALSE, NL$)

BASIC

Works with: QuickBASIC version 7

(older versions don't have DIR$)

DOS wildcards are rather underpowered when compared to... well... anything else.

Works with: FreeBASIC

DECLARE SUB show (pattern AS STRING)

show "*.*"

SUB show (pattern AS STRING)
    DIM f AS STRING
    f = DIR$(pattern)
    DO WHILE LEN(f)
        PRINT f
        f = DIR$
    LOOP
END SUB

BASIC256

call show ("c:\")
end

subroutine show (pattern$)
	f$ = dir(pattern$)
	while length(f$)
		print f$
		f$ = dir
	end while
end subroutine

Batch File

A simple command that displays all EXE files in System32 directory non-recursively.

dir /b "%windir%\system32\*.exe"

The same command inside FOR loop:

Inside a Batch File:

@for /F "tokens=*" %%F in ('dir /b "%windir%\system32\*.exe"') do echo %%F

Command-line:

for /F "tokens=*" %F in ('dir /b "%windir%\system32\*.exe"') do echo %F

BBC BASIC

Works with: BBC BASIC for Windows

      directory$ = "C:\Windows\"
      pattern$ = "*.ini"
      PROClistdir(directory$ + pattern$)
      END
      
      DEF PROClistdir(afsp$)
      LOCAL dir%, sh%, res%
      DIM dir% LOCAL 317
      SYS "FindFirstFile", afsp$, dir% TO sh%
      IF sh% <> -1 THEN
        REPEAT
          PRINT $$(dir%+44)
          SYS "FindNextFile", sh%, dir% TO res%
        UNTIL res% = 0
        SYS "FindClose", sh%
      ENDIF
      ENDPROC

C

Library: POSIX

Works with: POSIX version .1-2001

In this example, the pattern is a POSIX extended regular expression.

#include <sys/types.h>
#include <dirent.h>
#include <regex.h>
#include <stdio.h>

enum {
    WALK_OK = 0,
    WALK_BADPATTERN,
    WALK_BADOPEN,
};

int walker(const char *dir, const char *pattern)
{
    struct dirent *entry;
    regex_t reg;
    DIR *d; 

    if (regcomp(&reg, pattern, REG_EXTENDED | REG_NOSUB))
        return WALK_BADPATTERN;
    if (!(d = opendir(dir)))
        return WALK_BADOPEN;
    while (entry = readdir(d))
        if (!regexec(&reg, entry->d_name, 0, NULL, 0))
            puts(entry->d_name);
    closedir(d);
    regfree(&reg);
    return WALK_OK;
}

int main()
{
    walker(".", ".\\.c$");
    return 0;
}

C#

using System;
using System.IO;

namespace DirectoryWalk
{
    class Program
    {
        static void Main(string[] args)
        {
            string[] filePaths = Directory.GetFiles(@"c:\MyDir", "a*");
            foreach (string filename in filePaths)
                Console.WriteLine(filename);            
        }
    }
}

C++

Library: boost version 1.50.0

#include "boost/filesystem.hpp"
#include "boost/regex.hpp"
#include <iostream>

using namespace boost::filesystem;

int main()
{
  path current_dir(".");
  // list all files starting with a
  boost::regex pattern("a.*");
  for (directory_iterator iter(current_dir), end;
       iter != end;
       ++iter)
  {
    boost::smatch match;
    std::string fn = iter->path().filename().string(); // must make local variable
    if (boost::regex_match( fn, match, pattern))
    {
      std::cout << match[0] << "\n";
    }
  }
}

Library: std version C++17

#include <filesystem>
#include <iostream>

namespace fs = std::filesystem;

int main() {
  fs::path current_dir(".");
  // list all files containing an mp3 extension
  for (auto &file : fs::directory_iterator(current_dir)) {
    if (file.path().extension() == ".mp3")
      std::cout << file.path().filename().string() << std::endl;
  }
}

Clojure

Using Java 8's PathMatcher patterns.

(import java.nio.file.FileSystems)

(defn match-files [f pattern]
  (.matches (.getPathMatcher (FileSystems/getDefault) (str "glob:*" pattern)) (.toPath f)))

(defn walk-directory [dir pattern]
  (let [directory (clojure.java.io/file dir)]
    (map #(.getPath %) (filter #(match-files % pattern) (.listFiles directory)))))

ColdFusion

This example display all files and directories directly under C:\temp that end with .html

<cfdirectory action="list" directory="C:\temp" filter="*.html" name="dirListing">
<cfoutput query="dirListing">
  #dirListing.name# (#dirListing.type#)<br>
</cfoutput>

Common Lisp

(defun walk-directory (directory pattern)
  (directory (merge-pathnames pattern directory)))

Uses the filename pattern syntax provided by the CL implementation.

D

void main() {
    import std.stdio, std.file;

    dirEntries(".", "*.*", SpanMode.shallow).writeln;
}

DCL

* matches any number of characters
& matches exactly any one character

$ loop:
$  f = f$search( p1 )
$  if f .eqs. "" then $ exit
$  write sys$output f
$  goto loop

Output:

$ @walk_a_directory *.*
USERS:[DAVID]A.A;1
USERS:[DAVID]B.B;1
USERS:[DAVID]GG.GG;1
USERS:[DAVID]WALK_A_DIRECTORY.COM;1
$ @walk_a_directory *.%
USERS:[DAVID]A.A;1
USERS:[DAVID]B.B;1
$ @walk_a_directory *a*.*
USERS:[DAVID]A.A;1
USERS:[DAVID]WALK_A_DIRECTORY.COM;1
$

Delphi

Hand-coded

See: Pascal

Using System.IOUtils

Library: System.IOUtils

program Walk_a_directory;

{$APPTYPE CONSOLE}
{$R *.res}

uses
  System.IOUtils;

var
  Files: TArray<string>;
  FileName, Directory: string;

begin
  Directory := TDirectory.GetCurrentDirectory;  // dir = '.', work to
  Files := TDirectory.GetFiles(Directory, '*.*');

  for FileName in Files do
  begin
    Writeln(FileName);
  end;

  Readln;
end.

Output:

D:\Rosettacode\Walk_a_directory\Win32\Debug\Walk_a_directory.exe

E

def walkDirectory(directory, pattern) {
  for name => file ? (name =~ rx`.*$pattern.*`) in directory {
    println(name)
  }
}

Example:

? walkDirectory(<file:~>, "bash_")
.bash_history
.bash_profile
.bash_profile~

Elena

ELENA 6.x:

import system'io;
import system'routines;
import extensions'routines;
   
public program()
{
    var dir := Directory.assign("c:\MyDir");
    
    dir.getFiles("a.*").forEach(printingLn);
}

Elixir

# current directory
IO.inspect File.ls!

dir = "/users/public"
IO.inspect File.ls!(dir)

Output:

["check.exs", "e.bat", "foo", "input.txt", "test.beam", "test.exs", "test.txt"]
["Desktop", "desktop.ini", "Documents", "Downloads", "Favorites", "Libraries",
 "Music", "Pictures", "Recorded TV", "Videos"]

Emacs Lisp

directory-files gives filenames in a given directory, optionally restricted to those matching a regexp.

(directory-files "/some/dir/name"
                 nil        ;; just the filenames, not full paths
                 "\\.c\\'"  ;; regexp
                 t)         ;; don't sort the filenames
;;=> ("foo.c" "bar.c" ...)

Erlang

Use builtin function filelib:fold_files/5

Output:

8> filelib:fold_files( "/tmp", ".*", false, fun(File, Acc) -> [File|Acc] end, []).  
["/tmp/.X0-lock","/tmp/.cron-check-4000-was-here",
 "/tmp/kerneloops.XyN0SP","/tmp/npicagwD7tf"]
9> filelib:fold_files( "/tmp", "k.*P", false, fun(File, Acc) -> [File|Acc] end, []).
["/tmp/kerneloops.XyN0SP"]

Euphoria

include file.e

procedure show(sequence pattern)
    sequence f
    f = dir(pattern)
    for i = 1 to length(f) do
        puts(1,f[i][D_NAME])
        puts(1,'\n')
    end for
end procedure

show("*.*")

F#

System.IO.Directory.GetFiles("c:\\temp", "*.xml")
|> Array.iter (printfn "%s")

Factor

Using unix globs. Also see the "directory." in basis/tools/files.factor.

USING: globs io io.directories kernel regexp sequences ;
IN: walk-directory-non-recursively

: print-files ( path pattern -- )
    [ directory-files ] [ <glob> ] bi* [ matches? ] curry filter
    [ print ] each ;

Ex:

   ( scratchpad ) "." "*.txt" print-files
   license.txt

Forth

Works with: gforth version 0.6.2

Gforth's directory walking functions are tied to the POSIX dirent functions, used by the C langauge entry above. Forth doesn't have regex support, so a simple filter function is used instead.

defer ls-filter ( name len -- ? )
: ls-all  2drop true ;
: ls-visible  drop c@ [char] . <> ;

: ls ( dir len -- )
  open-dir throw  ( dirid )
  begin
    dup pad 256 rot read-dir throw
  while
    pad over ls-filter if
      cr pad swap type
    else drop then
  repeat
  drop close-dir throw ;

\ only show C language source and header files (*.c *.h)
: c-file? ( str len -- ? )
  dup 3 < if 2drop false exit then
  + 1- dup c@
   dup [char] c <> swap [char] h <> and if drop false exit then
  1- dup c@ [char] . <> if drop false exit then
  drop true ;
' c-file? is ls-filter

s" ." ls

FreeBASIC

Translation of: BASIC

Sub show (pattern As String)
    Dim As String f = Dir$(pattern)
    While Len(f)
        Print f
        f = Dir$
    Wend
End Sub

show "*.*"
Sleep

Frink

This prints the names of all of the files in the current directory that end with .frink using a regular expression.

for f = select[files["."], {|f1| f1.getName[] =~ %r/\.frink$/}]
   println[f.getName[]]

Output:

UTMtest.frink
mersennetest.frink
piChudnovskyNew.frink
showFonts.frink
graphicalSieve.frink
...

FutureBasic

include "NSLog.incl"

void local fn EnumerateDirectoryAtURL( dirURL as CFURLRef )
  NSDirectoryEnumerationOptions options = NSDirectoryEnumerationSkipsPackageDescendants + ¬
  NSDirectoryEnumerationSkipsHiddenFiles + ¬
  NSDirectoryEnumerationSkipsSubdirectoryDescendants
  
  DirectoryEnumeratorRef enumerator = fn FileManagerEnumeratorAtURL( dirURL, NULL, options, NULL, NULL )
  CFURLRef url = fn EnumeratorNextObject( enumerator )
  while ( url )
    if ( fn StringIsEqual( fn URLPathExtension( url ), @"fb" ) )
      NSLog(@"%@",fn URLLastPathComponent( url ))
    end if
    url = fn EnumeratorNextObject( enumerator )
  wend
end fn

fn EnumerateDirectoryAtURL( fn FileManagerURLForDirectory( NSDesktopDirectory, NSUserDomainMask ) )

HandleEvents

Output:

ListFormatter.fb
ObjectProperty1.fb
Archimedean Spiral with Bezier Curve.fb
FB3D.fb
lenArray.fb
Rosettacode Random Noise v04.fb
AssociatedObject.fb

Gambas

Click this link to run this code

Public Sub Main()
Dim sTemp As String
 
For Each sTemp In Dir("/etc", "*.d")
  Print sTemp
Next

End

Output:

profile.d
rc1.d
rc4.d
rcS.d
binfmt.d
init.d
rc5.d
rc2.d

Go

package main

import (
    "fmt"
    "path/filepath"
)

func main() {
    fmt.Println(filepath.Glob("*.go"))
}

Groovy

// *** print *.txt files in current directory
 new File('.').eachFileMatch(~/.*\.txt/) {
   println it
 }

 // *** print *.txt files in /foo/bar
 new File('/foo/bar').eachFileMatch(~/.*\.txt/) {
   println it
 }

Hare

use fmt;
use glob;

export fn main() void = {
	ls("/etc/*.conf");
};

fn ls(pattern: str) void = {
	let gen = glob::glob(pattern, glob::flags::NONE);
	defer glob::finish(&gen);
	for (true) match (glob::next(&gen)) {
	case void =>
		break;
	case glob::failure =>
		continue;
	case let s: str =>
		fmt::printfln("{}", s)!;
	};
};

Haskell

Works with: GHCi version 6.6

In this example, the pattern is a POSIX extended regular expression.

import System.Directory
import Text.Regex
import Data.Maybe

walk :: FilePath -> String -> IO ()
walk dir pattern = do
    filenames <- getDirectoryContents dir
    mapM_ putStrLn $ filter (isJust.(matchRegex $ mkRegex pattern)) filenames

main = walk "." ".\\.hs$"

HicEst

Icon and Unicon

This uses Unicon extensions for stat and to read directories. Icon can uses system to accomplish the same objective.

procedure main()
every write(getdirs(".","icn"))  # writes out all directories from the current directory down
end
 
procedure getdirs(s,pat)  #: return a list of directories beneath the directory 's'
local d,f
 
if ( stat(s).mode ? ="d" ) & ( d := open(s) ) then {
      while f := read(d) do 
         if find(pat,f) then 
            suspend f
      close(d)
      }
end

IDL

f = file_search('*.txt', count=cc)
if cc gt 0 then print,f

(IDL is an array language - very few things are ever done in 'loops'.)

J

require 'dir'
0 dir '*.png'
0 dir '/mydir/*.txt'

The verb dir supports a number of reporting options determined by its left argument. A left argument of 0 reports just the file names.

Java

File dir = new File("/foo/bar");

String[] contents = dir.list();
for (String file : contents)
    if (file.endsWith(".mp3"))
        System.out.println(file);

JavaScript

Works with: JScript

var fso = new ActiveXObject("Scripting.FileSystemObject");
var dir = fso.GetFolder('test_folder');

function walkDirectory(dir, re_pattern) {
    WScript.Echo("Files in " + dir.name + " matching '" + re_pattern +"':");
    walkDirectoryFilter(dir.Files, re_pattern);

    WScript.Echo("Folders in " + dir.name + " matching '" + re_pattern +"':");
    walkDirectoryFilter(dir.Subfolders, re_pattern);
}

function walkDirectoryFilter(items, re_pattern) {
    var e = new Enumerator(items);
    while (! e.atEnd()) {
        var item = e.item();
        if (item.name.match(re_pattern))
            WScript.Echo(item.name);
        e.moveNext();
    }
}

walkDirectory(dir, '\\.txt$');

Julia

Works with: Julia version 0.6

for filename in readdir("/foo/bar")
    if endswith(filename, ".mp3")
        print(filename)
    end
end

Kotlin

// version 1.1.2

import java.io.File

fun walkDirectory(dirPath: String, pattern: Regex): List<String> {
    val d = File(dirPath)
    require(d.exists() && d.isDirectory())
    return d.list().filter { it.matches(pattern) }
}

fun main(args: Array<String>) {
    val r = Regex("""^a.*\.h$""")  // get all C header files beginning with 'a'
    val files = walkDirectory("/usr/include", r)
    for (file in files) println(file)
}

Sample output (Ubuntu v14.04):

Output:

argp.h
alloca.h
ar.h
aliases.h
autosprintf.h
aio.h
assert.h
argz.h

Lasso

local(matchingfilenames = array)

dir('.') -> foreach => {#1 >> 'string' ? #matchingfilenames -> insert(#1)}

#matchingfilenames

-> array(mystrings.html, a_string_file.txt)

Lingo

-- Usage: printFiles("C:\scripts", ".ls")
on printFiles (dir, fileType)
  i = 1
  sub = fileType.length -1
  repeat while TRUE
    fn = getNthFileNameInFolder(dir, i) 
    if fn = EMPTY then exit repeat
    i = i+1
    if fn.length<fileType.length then next repeat
    if fn.char[fn.length-sub..fn.length]=fileType then put fn
  end repeat
end

LiveCode

set the defaultFolder to the documents folder  -- the documents folder is a "specialFolderPath"
put the files into docfiles
filter docfiles with "*.txt"
put docfiles

Lua

Lua itself is extremely spartanic as it is meant for embedding. Reading out a directory is not something that a minimal standard C library can do, and so minimal Lua without native extension libraries can't do it either. But lfs (LuaFileSystem) is about as standard an extension as it gets, so we use that.

require "lfs"
directorypath = "." -- current working directory
for filename in lfs.dir(directorypath) do
    if filename:match("%.lua$") then -- "%." is an escaped ".", "$" is end of string
        print(filename)
    end
end

Although Lua is spartanic, it still provides functions such as os.execute([command]) and io.popen(prog [, mode]). Below an example for Windows users having io.popen at their disposal. Mind you, it may pop-up a command window.

-- Gets the output of given program as string
-- Note that io.popen is not available on all platforms
local function getOutput(prog)
    local file = assert(io.popen(prog, "r"))
    local output = assert(file:read("*a"))
    file:close()
    return output
end

-- Iterates files in given directory
local function files(directory, recursively)
    -- Use windows" dir command
    local directory = directory:gsub("/", "\\")
    local filenames = getOutput(string.format("dir %s %s/B/A:A", directory, recursively and '/S' or ''))
    
    -- Function to be called in "for filename in files(directory)"
    return coroutine.wrap(function()
        for filename in filenames:gmatch("([^\r\n]+)") do
            coroutine.yield(filename)
        end    
    end)
end

-- Walk "C:/Windows" looking for executables
local directory = "C:/Windows"
local pattern = ".*%.exe$" -- for finding executables
for filename in files(directory) do
    if filename:match(pattern) then
        print(filename)
    end
end

M2000 Interpreter

Console has a popup list called Menu, which we can fill using Files statements. Files statement get some symbols before first argument for sorting and to not export to console but to menu list. So we can use MenuItems to find how many items return, and we can walk menu array to get the names (from 1 to MenuItems).

Files statement get as first argument a pattern or a list of file extensions "txt|bmp" return these two kind of files. There is a second optional parameter which examine all files founded from first filter for included letters. We can add using | as seperator, a list of strings included in same line. Files examine all files, opened one by one, using an automatic way to find what kind of text file is, an Ansi, a Utf8, a Utf-16LE, or a Utf-16BE. Also automatic find the line breaks. All files converted at open as utf-16LE and then searched. For Ansi files, Locale used to make the right conversion.

Module Show_Files_Standard {
      \\ we get more (include hidden too)
      Module InnerWay (folder_path$, pattern$){
            olddir$=dir$
            dir folder_path$
            \\ clear menu list
            Menu
            \\ + place export to menu, without showing
            \\ ! sort to name
            files ! + pattern$
            If MenuItems>0 then {
                  For i=1 to MenuItems {
                        Print Menu$(i)+".exe"
                  }
            }
            dir olddir$
      }
      InnerWay "C:\Windows","*.exe"
}
Show_Files_Standard

Like VbScript using external help, from a COM object.

We use an enumerator to iterate all file names and checked using like operator "~",and then we push them to end of stack (Data push to end), so we get first the first entered (we use stack here as a FIFO, using a New stack for temporary use), and we remove at the end all items and place them in an array. This array return from get_file$() and we make a second iterator for array, to get each end display it. The second iterator is not a com enumerator, but another type of object included in this interpreter. This iterator can get start and end position, defining a range and a direction too.

EnumFile is an object in an object. In expression we get the inner object. In While {} we get the outer object, and iterate or not (depends of state), so the inner object change. Because we get the first object at creation time, the first time when While structure found this object skips iteration.

Stack New {} make a block of a fresh stack of values, and at the exit attach the old stack (which for this block detached from execute object at the begin of block).

Module Show_Files {
      Function  get_files$ (folder_path$) {
            \\ we get second argument using letter$ which pop from stack
            pattern$=lcase$(Letter$)
            Declare  objfso "Scripting.FileSystemObject"
            Method objfso, "GetFolder", folder_path$ as fc
            With fc, "files" set files
            \\ from revision 13 - version 9.4
            With files, -4& as EnumFile
            With EnumFile, "Name" as name$
            Dim empty$()
            =empty$()
            Stack New {
                  While EnumFile {
                        If lcase$(name$) ~ pattern$ Then Data name$
                  }
                  \\ get stack values and fill an array
                  =Array$([])
            }
      }
      Dim Name$()
      Name$()=get_files$("C:\Windows","*.exe")
      m=each(Name$())
      While m {
            Print Array$(m)
      }
}
Show_Files

MACRO-10

        TITLE  DIRWLK - Directory Walker
        SUBTTL PDP-10 Assembly Language (MACRO-10 @ TOPS-20). KJX 2022.

        SEARCH MONSYM,MACSYM            ;Get system-call names.
        .REQUIRE SYS:MACREL             ;Macros: TMSG, EJSHLT, etc.

        STDAC.                          ;Define standard register names.

JFN:    BLOCK 1                         ;Space for JFN (file-handle)
FSPEC:  BLOCK 20                        ;Space for file specification.
FSPECL= <.-FSPEC>*5                     ;Length in chars of file-spec.

GO::    RESET%                          ;Initialize process.
        TMSG <Please enter filespec, wildcards are allowed: >
        HRROI T1,FSPEC                  ;Read into FSPEC.
        MOVEI T2,FSPECL                 ;Maximum allowed characters.
        SETZ  T3,                       ;No Ctrl-R prompting.
        RDTTY%                          ;Read string from terminal.
          EJSHLT                        ;  Print error-msg on errors.

        MOVX  T1,GJ%OLD!GJ%IFG!GJ%FLG!GJ%SHT  ;Various flags.
        HRROI T2,FSPEC                  ;File specification from above.
        GTJFN%                          ;Get JFN for first matching file.
          EJSHLT                        ;  Print error-msg on errors.
        MOVEM T1,JFN                    ;Save JFN.

        DO.
          MOVEI T1,.PRIOU               ;Write to standard-output.
          HRRZ  T2,JFN                  ;JFN from above to decode.
          SETZ  T3,                     ;No flags.
          JFNS%                         ;Decode filename and print it.
            EJSHLT                      ;  Print error-msg on errors.
          TMSG <
>                                       ;Print newline.
          MOVE  T1,JFN                  ;Get JFN into T1.
          GNJFN%                        ;Get next matching file.
            JRST [ HALTF%               ;  Halt program on failure.
                   JRST GO ]
          LOOP.                         ;No error: Do it again.
        ENDDO.

        END GO

Mathematica/Wolfram Language

The built-in function FileNames does exactly this:

FileNames[] lists all files in the current working directory.

FileNames[form] lists all files in the current working directory whose names match the string pattern form.

FileNames[{form1,form2,...}] lists all files whose names match any of the form_i.

FileNames[forms,{dir1,dir2,...}] lists files with names matching forms in any of the directories dir_i.

FileNames[forms,dirs,n] includes files that are in subdirectories up to n levels down.

Examples (find all files in current directory, find all png files in root directory):

FileNames["*"]
FileNames["*.png", $RootDirectory]

the result can be printed with Print /@ FileNames[....].

MAXScript

getFiles "C:\\*.txt"

Nanoquery

import Nanoquery.IO

for fname in new(File).listDir("/foo/bar")
	if lower(new(File, fname).getExtension()) = ".mp3"
		println filename
	end
end

Nemerle

using System.Console;
using System.IO;

module DirWalk
{
    Main() : void
    {
        def files = Directory.GetFiles(@"C:\MyDir");                  // retrieves only files
        def files_subs = Directory.GetFileSystemEntries(@"C:\MyDir"); // also retrieves (but does not enter) sub-directories
                                                                      // (like ls command)
        foreach (file in files) WriteLine(file);
    }
}

NetRexx

/* NetRexx */
options replace format comments java crossref symbols nobinary

import java.util.List

runSample(arg)
return

-- ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
method getFileNames(dirname, pattern) public static returns List
  dir = File(dirname)
  contents = dir.list()
  fileNames = ArrayList()
  loop fname over contents
    if fname.matches(pattern) then do
      fileNames.add(fname)
      end
    end fname
  Collections.sort(fileNames)
  return fileNames

-- ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
method runSample(arg) private static
  parse arg dirname pattern
  if dirname = '' then dirname = System.getProperty('user.dir')
  if pattern = '' then pattern = '^RW.*\\.nrx$'

  fileNames = getFileNames(dirname, pattern)
  say 'Search of' dirname 'for files matching pattern "'pattern'" found' fileNames.size() 'files.'
  loop fn = 0 while fn < fileNames.size()
    say (fn + 1).right(5)':' fileNames.get(fn)
    end fn
  
  return

Output:

Search of /Users/projects/RosettaCode/netrexx for files matching pattern "^RW.*\.nrx$" found 5 files.
    1: RWalkDir_Iter.nrx
    2: RWebScraping.nrx
    3: RWindowCreate.nrx
    4: RWriteFloatArray.nrx
    5: RWriteName3D01.nrx

Nim

The “os” standard module provides several iterators to retrieve files or directories matching a pattern: walkPattern to retrieve files and directories, walkFiles to retrieve only files and walkDirs to retrieve only directories. The pattern is OS dependent but at least the *.ext notation is supported.

And there is the powerful walkDir to list the content of a directory specified by its name (without pattern). Here is an example with walkFiles and a pattern:

import os

for file in walkFiles "/foo/bar/*.mp3":
  echo file

Objeck

use IO;

bundle Default {
  class Test {
    function : Main(args : System.String[]) ~ Nil {
       dir := Directory->List("/src/code");
       for(i := 0; i < dir->Size(); i += 1;) {
         if(dir[i]->EndsWith(".obs")) {
           dir[i]->PrintLine();
        };
      };
    }
  }
}

Objective-C

NSString *dir = @"/foo/bar";

// Pre-OS X 10.5
NSArray *contents = [[NSFileManager defaultManager] directoryContentsAtPath:dir];
// OS X 10.5+
NSArray *contents = [[NSFileManager defaultManager] contentsOfDirectoryAtPath:dir error:NULL];

for (NSString *file in contents)
  if ([[file pathExtension] isEqualToString:@"mp3"])
    NSLog(@"%@", file);

OCaml

#load "str.cma"
let contents = Array.to_list (Sys.readdir ".") in
let select pat str = Str.string_match (Str.regexp pat) str 0 in
List.filter (select ".*\\.jpg") contents

Odin

package main

import "core:fmt"
import "core:path/filepath"

main :: proc() {
  matches, _err := filepath.glob("*.odin")
  for match in matches do fmt.println(match)
}

Oz

declare
  [Path] = {Module.link ['x-oz://system/os/Path.ozf']}
  [Regex] = {Module.link ['x-oz://contrib/regex']}

  Files = {Filter {Path.readdir "."} Path.isFile}
  Pattern = ".*\\.oz$"
  MatchingFiles = {Filter Files fun {$ File} {Regex.search Pattern File} \= false end}
in
  {ForAll MatchingFiles System.showInfo}

Pascal

Works with: Free Pascal

{$H+}

program Walk;

uses SysUtils;

var Res: TSearchRec;
    Pattern, Path, Name: String;
    FileAttr: LongInt;
    Attr: Integer;

begin
   Write('File pattern: ');
   ReadLn(Pattern);            { For example .\*.pas }
   
   Attr := faAnyFile;
   if FindFirst(Pattern, Attr, Res) = 0 then
   begin
      Path := ExtractFileDir(Pattern);
      repeat
         Name := ConcatPaths([Path, Res.Name]);
         FileAttr := FileGetAttr(Name);
         if FileAttr and faDirectory = 0 then
         begin
            { Do something with file name }
            WriteLn(Name);
         end
      until FindNext(Res) <> 0;
   end;
   FindClose(Res);
end.

Perl

use 5.010;
opendir my $dh, '/home/foo/bar';
say for grep { /php$/ } readdir $dh;
closedir $dh;

Or using globbing, with the <> operator,

use 5.010; say while </home/foo/bar/*.php>;

Or the same with the builtin glob() function,

my @filenames = glob('/home/foo/bar/*.php');

The glob() function takes any expression for its pattern, whereas <> is only for a literal.

my $pattern = '*.c';
my @filenames = glob($pattern);

Phix

Library: Phix/basics

The dir function accepts a DOS pattern, with some minor variations (eg "*" gets all files with no extension).

puts(1,join(columnize(dir("*.txt"))[D_NAME],"\n"))

Output:

copyright.txt
e-1millon.txt
ildump.txt
output.txt
readme.txt
_TODO.TXT

PHP

Works with: PHP version 5.2.0

$pattern = 'php';
$dh = opendir('c:/foo/bar'); // Or '/home/foo/bar' for Linux
while (false !== ($file = readdir($dh)))
{
    if ($file != '.' and $file != '..')
    {
        if (preg_match("/$pattern/", $file))
        {
            echo "$file matches $pattern\n";
        }
    }
}
closedir($dh);

Or:

$pattern = 'php';
foreach (scandir('/home/foo/bar') as $file)
{
    if ($file != '.' and $file != '..')
    {
        if (preg_match("/$pattern/", $file))
        {
            echo "$file matches $pattern\n";
        }
    }
}

Works with: PHP version 4 >= 4.3.0 or 5

foreach (glob('/home/foo/bar/*.php') as $file){
    echo "$file\n";
}

PicoLisp

(for F (dir "@src/")                         # Iterate directory
   (when (match '`(chop "s@.c") (chop F))    # Matches 's*.c'?
      (println F) ) )                        # Yes: Print it

Output:

"start.c"
"ssl.c"
"subr.c"
"sym.c"
...

Pike

array(string) files = get_dir("/home/foo/bar");
foreach(files, string file)
    write(file + "\n");

Pop11

Built-in procedure sys_file_match searches directories (or directory trees) using shell-like patterns:

lvars repp, fil;
;;; create path repeater
sys_file_match('*.p', '', false, 0) -> repp;
;;; iterate over files
while (repp() ->> fil) /= termin do
     ;;; print the file
     printf(fil, '%s\n');
endwhile;

PowerShell

Since PowerShell is also a shell it should come as no surprise that this task is very simple. Listing the names of all text files, or the names of all files, starting with "f":

Get-ChildItem *.txt -Name
Get-ChildItem f* -Name

The -Name parameter tells the Get-ChildItem to return only the file names as string, otherwise a complete FileInfo or DirectoryInfo object would be returned, containing much more information than only the file name.

More complex matching can be accomplished by filtering the complete list of files using the Where-Object cmdlet. The following will output all file names that contain at least one vowel:

Get-ChildItem -Name | Where-Object { $_ -match '[aeiou]' }

PureBasic

The match is made using DOS wildcards. It could easily be modified to match based on a regular expression if desired (i.e. using the PCRE library).

Procedure walkDirectory(directory.s = "", pattern.s = "")
  Protected directoryID
  
  directoryID = ExamineDirectory(#PB_Any,directory,pattern)
  If directoryID
    While NextDirectoryEntry(directoryID)
      PrintN(DirectoryEntryName(directoryID))
    Wend
    FinishDirectory(directoryID)
  EndIf 
EndProcedure

If OpenConsole()
  walkDirectory()  
  
  Print(#CRLF$ + #CRLF$ + "Press ENTER to exit")
  Input()
  CloseConsole()
EndIf

Python

The glob library included with Python lists files matching shell-like patterns:

import glob
for filename in glob.glob('/foo/bar/*.mp3'):
    print(filename)

Or manually:

import os
for filename in os.listdir('/foo/bar'):
    if filename.endswith('.mp3'):
        print(filename)

R

dir("/foo/bar", "mp3")

Racket

-> (for ([f (directory-list "/tmp")] #:when (regexp-match? "\\.rkt$" f))
     (displayln f))
... *.rkt files ...

Raku

(formerly Perl 6) The dir function takes the directory to traverse, and optionally a named parameter test, which is smart-matched against the basename of each file (so for example we can use a regex):

.say for dir ".", :test(/foo/);

Rascal

import IO;
public void Walk(loc a, str pattern){
	for (entry <- listEntries(a))
		endsWith(entry, pattern) ? println(entry);
}

Raven

'dir://.' open each as item
    item m/\.txt$/ if "%(item)s\n" print

REXX

Works with: Regina

The following program was tested in a DOS window under Windows/XP and should work for all Microsoft Windows.

/*REXX program shows files in directory tree that match a given criteria*/
parse arg xdir;  if xdir='' then xdir='\'        /*Any DIR? Use default.*/
@.=0                                   /*default in case ADDRESS fails. */
trace off                              /*suppress REXX err msg for fails*/
address system 'DIR' xdir '/b /s' with output stem @.   /*issue DIR cmd.*/
if rc\==0  then do                                  /*an error happened?*/
                say '***error!*** from DIR' xDIR    /*indicate que pasa.*/
                say 'return code='  rc              /*show the Ret Code.*/
                exit rc                             /*exit with the  RC.*/
                end                                 /* [↑]  bad address.*/
#=@.rc                                              /*number of entries.*/
if #==0  then #='   no   '                          /*use a word, ¬zero.*/
say center('directory ' xdir " has "    #     ' matching entries.',79,'─')

       do j=1  for #;  say @.j;  end   /*show files that met criteria.  */

exit @.0+rc                            /*stick a fork in it, we're done.*/

Ring

###---------------------------------------
### Directory Tree Walk
### Look for FileType for Music and Video

fileType = [".avi", ".mp4", ".mpg", ".mkv", ".mp3", ".wmv" ]

dirList   = []
musicList = []

###---------------------------------------
### Main
    
    ###-----------------------------------
    ### Start at this directory
    
    searchVideoMusic("C:\Users\Umberto\")

    see nl +"Number of Music and Videos files: " +len(musicList) +nl +nl
    see musicList
    See nl +"Finished" +nl

###=======================================
### Search for Video and Music files

Func searchVideoMusic(startDir)

    ChDir(startDir + "Music")     ### <<<== add Music subpath C:\Users\Umberto\Music
    listDir( CurrentDir() )

    ChDir(startDir + "Videos")    ### <<<== add Videos subpath C:\Users\Umberto\Videos
    listDir( CurrentDir() )

    for searchDir in dirList      ### Search Directory List for Music and Videos files
        listDir(searchDir)
    next


###==============================
### Find Files in Directory

Func listDir(dirName)

    ChDir(dirName)
    Try
        ###-------------------------------------
        ### Get SubDirectories

        myListSub = Dir( CurrentDir() )
    Catch
        ###-------------------------------------
        ### Error, Couldn't open the directory

        See "ListDir Catch! " + CurrentDir() +" --- "+ cCatchError +nl
        return
    Done

    for x in myListSub
        if x[2]
            thisDir = x[1]

            if thisDir[1] = "."
                ### Do Nothing. Ignore dot.name

            else
                see nl +"Dir: " + CurrentDir() +"\"+ thisDir + nl

                ###----------------------------------------
                ###  Directory Walk add to directory list

                Add( dirList, (CurrentDir() +"\"+  thisDir))
            ok
        else
            thisFile = x[1]

            ###-------------------------------
            ### Add Music or Video file type

            for thisType in fileType
                if ( substr(thisFile, thisType) )             ### <<<== Type of File from List
                     see "         File: " + thisFile + nl
                     Add(musicList, (CurrentDir() +"\"+  thisFile))
                ok
            next
        ok
    next
return

###===============================================

OUTPUT:


Dir: C:\Users\Umberto\Music\Free YouTube Downloader
         File: stock.mp3
         File: big_buck_bunny.mp4
         File: BowieNikolaTesla'ThePrestige'.mpg
         File: BowieTesla'The Prestige'.wmv
         File: Candyman.mp4

Dir: C:\Users\Umberto\Videos\Captures
         File: drop.avi

Dir: C:\Users\Umberto\Videos\Free YouTube Downloader
         File: GaryUSBondsQuarterToThree.avi

Dir: C:\Users\Umberto\Videos\HitomiTanaka[MIDE-219]
         File: Joe.Versus.The.Volcano[1990].avi
         File: SampleTheMythSanWa2005.mkv
         File: stock.mp3

Dir: C:\Users\Umberto\Videos\The Prestige (2006)
         File: BowieNikola'The Prestige'.mp4
         File: BowieTeslaThe PrestigeConverted.mpg
         File: 027_3xplanet_MDYD-895.avi
         File: 3.mpg
         File: HitomiTanaka[MIDE-219].mp4
         File: MDYD-868.wmv
         File: MIDE-253.mp4
         File: MIDE_280.mp4
         File: PPPD-432.avi
         File: The.Prestige.2006.mkv

Number of Music and Videos files: 20

C:\Users\Umberto\Music\stock.mp3
C:\Users\Umberto\Videos\big_buck_bunny.mp4
C:\Users\Umberto\Videos\BowieNikolaTesla'ThePrestige'.mpg
C:\Users\Umberto\Videos\BowieTesla'The Prestige'.wmv
C:\Users\Umberto\Videos\Candyman.mp4
C:\Users\Umberto\Videos\drop.avi
C:\Users\Umberto\Videos\GaryUSBondsQuarterToThree.avi
C:\Users\Umberto\Videos\Joe.Versus.The.Volcano[1990].avi
C:\Users\Umberto\Videos\SampleTheMythSanWa2005.mkv
C:\Users\Umberto\Videos\stock.mp3
C:\Users\Umberto\Videos\Free YouTube Downloader\BowieNikola'The Prestige'.mp4
C:\Users\Umberto\Videos\Free YouTube Downloader\BowieTeslaThe PrestigeConverted.mpg
C:\Users\Umberto\Videos\HitomiTanaka[MIDE-219]\027_3xplanet_MDYD-895.avi
C:\Users\Umberto\Videos\HitomiTanaka[MIDE-219]\3.mpg
C:\Users\Umberto\Videos\HitomiTanaka[MIDE-219]\HitomiTanaka[MIDE-219].mp4
C:\Users\Umberto\Videos\HitomiTanaka[MIDE-219]\MDYD-868.wmv
C:\Users\Umberto\Videos\HitomiTanaka[MIDE-219]\MIDE-253.mp4
C:\Users\Umberto\Videos\HitomiTanaka[MIDE-219]\MIDE_280.mp4
C:\Users\Umberto\Videos\HitomiTanaka[MIDE-219]\PPPD-432.avi
C:\Users\Umberto\Videos\The Prestige (2006)\The.Prestige.2006.mkv

Finished

RPL

Works with: Halcyon Calc version 4.2.7

The very first instruction of this program VARS returns the list of all current files and subdirectories. The rest of the code retains the names that comply with the pattern given in input, and which are not directories. To do so, the program attempts to recall the contents of each object on the stack through RCL: if an error occurs, the object is then a directory and shall not be processed further.

≪ VARS → filter list 
   ≪ { } 1 list SIZE FOR j 
      list j GET 
      IFERR DUP RCL THEN DROP2 
      ELSE 
         DROP →STR 2 OVER SIZE 1 - SUB 
         IF DUP filter POS THEN + ELSE DROP END 
      END 
  NEXT 
≫ ≫
'WKDIR' STO

"T" WKDIR

Output:

1: { "T" "TESTPGM" "FACTN" }

Ruby

# Files under this directory:
Dir.glob('*') { |file| puts file }

# Files under path '/foo/bar':
Dir.glob( File.join('/foo/bar', '*') ) { |file| puts file }

# As a method
def file_match(pattern=/\.txt/, path='.')
  Dir[File.join(path,'*')].each do |file|
    puts file if file =~ pattern
  end
end

Run BASIC

files #g, DefaultDir$ + "\*.jpg"   ' find all jpg files 
 
if #g HASANSWER() then
	count = #g rowcount()	' get count of files
	for i = 1 to count
	if #g hasanswer() then	'retrieve info for next file
		#g nextfile$()	'print name of file
		print #g NAME$()
	end if
	next
end if
wait

FILE ACCESSOR methods

handle HASANSWER() - Return non-zero if the file accessor has at least one resulting row.
handle ROWCOUNT() - Return the number of rows returned.
handle NEXTFILE$() - Advance to the next row and return a comma delimited string for the next file (name, size, date, time, directory flag).
handle NEXTFILE$([delimExpr$]) - Like NEXTFILE$() but you get to specify the delimiter instead of a comma.
handle NAME$() - Return the name of the current file row.
handle SIZE() - Return the size of the current file row.
handle DATE$() - Return a string containing a formatted date for the current file row.
handle TIME$() - Return a string containing a formatted time for the current file row.
handle ISDIR() - Return non-zero if the current file row represents a directory instead of a file.
handle RESET() - Reset the file accessor back to the beginning so you can read through them again.
handle DATEFORMAT(template$) - Set the date format using a "mmm dd, yyyy" style template$.
handle TIMEFORMAT(template$) - Set the time format using a "hh:mm:ss" style template$.
handle ISNULL() - Returns zero (or false)
handle DEBUG$() - Returns the string "Files"

OUTPUT:

button.JPG
circuitbanner1.JPG
circuitbanner2.JPG
copy.jpg
homecomputerbanner1.JPG
mandelbrot.jpg

Rust

extern crate docopt;
extern crate regex;
extern crate rustc_serialize;

use docopt::Docopt;
use regex::Regex;

const USAGE: &'static str = "
Usage: rosetta <pattern>

Walks the directory tree starting with the current working directory and
print filenames matching <pattern>.
";

#[derive(Debug, RustcDecodable)]
struct Args {
    arg_pattern: String,
}

fn main() {
    let args: Args = Docopt::new(USAGE)
        .and_then(|d| d.decode())
        .unwrap_or_else(|e| e.exit());

    let re = Regex::new(&args.arg_pattern).unwrap();
    let paths = std::fs::read_dir(".").unwrap();

    for path in paths {
        let path = path.unwrap().path();
        let path = path.to_str().unwrap();

        if re.is_match(path) {
            println!("{}", path);
        }
    }
}

Scala

import java.io.File

val dir = new File("/foo/bar").list()
dir.filter(file => file.endsWith(".mp3")).foreach(println)

Seed7

$ include "seed7_05.s7i";
  include "osfiles.s7i";

const proc: main is func
  local
    var string: fileName is "";
  begin
    for fileName range readDir(".") do
      if endsWith(fileName, ".sd7") then
        writeln(fileName);
      end if;
    end for;
  end func;

Sidef

'*.p[lm]'.glob.each { |file| say file }    # Perl files under this directory

Output:

x.pl
x.pm

func file_match(Block callback, pattern=/\.txt\z/, path=Dir.cwd) {
    path.open(\var dir_h) || return nil
    dir_h.entries.each { |entry|
        if (entry.basename ~~ pattern) {
            callback(entry)
        }
    }
}
 
file_match(
    path: %d'/tmp',
    pattern: /\.p[lm]\z/i,
    callback: { |file|
        say file;
    }
)

Output:

/tmp/x.pl
/tmp/x.pm

Smalltalk

(Directory name: 'a_directory')
  allFilesMatching: '*.st' do: [ :f | (f name) displayNl ]

Standard ML

fun dirEntries path =
  let
    fun loop strm =
      case OS.FileSys.readDir strm of
        SOME name => name :: loop strm
      | NONE => []
    val strm = OS.FileSys.openDir path
  in
    loop strm before OS.FileSys.closeDir strm
  end

List all "hidden" files (starting with a dot in Unix) in the current directory:

(print o concat o map (fn s => s ^ "\n") o List.filter (String.isPrefix ".") o dirEntries) "."

Tcl

For the current directory:

foreach filename [glob *.txt] {
    puts $filename
}

For an arbitrary directory:

set dir /foo/bar
foreach filename [glob -directory $dir *.txt] {
    puts $filename
    ### Or, if you only want the local filename part...
    # puts [file tail $filename]
}

Toka

As with the C example, this uses a a POSIX extended regular expression as the pattern. The dir.listByPattern function used here was introduced in library revision 1.3.

needs shell
" ."  " .\\.txt$" dir.listByPattern

TUSCRIPT

$$ MODE TUSCRIPT
files=FILE_NAMES (+,-std-)
fileswtxt= FILTER_INDEX (files,":*.txt:",-)
txtfiles= SELECT (files,#fileswtxt)

Output:

files     DEST'MAKROS'ROSETTA.TXT'SKRIPTE'STUDENTS.XML'TUSTEP.INI
fileswtxt 3
txtfiles  ROSETTA.TXT

TXR

Using `glob`

(glob "/etc/*.conf")

Output:

("/etc/adduser.conf" "/etc/apg.conf" "/etc/blkid.conf" "/etc/brltty.conf"
 "/etc/ca-certificates.conf" "/etc/colord.conf" "/etc/ddclient.conf"
 "/etc/debconf.conf" "/etc/deluser.conf" "/etc/dnsmasq.conf" "/etc/ffserver.conf"
 "/etc/fuse.conf" "/etc/gai.conf" "/etc/hdparm.conf" "/etc/host.conf"
 "/etc/insserv.conf" "/etc/irssi.conf" "/etc/kernel-img.conf"
 "/etc/kerneloops.conf" "/etc/knockd.conf" "/etc/ld.so.conf" "/etc/lftp.conf"
 "/etc/logrotate.conf" "/etc/ltrace.conf" "/etc/mke2fs.conf" "/etc/mtools.conf"
 "/etc/netscsid.conf" "/etc/nsswitch.conf" "/etc/ntp.conf" "/etc/pam.conf"
 "/etc/pnm2ppa.conf" "/etc/popularity-contest.conf" "/etc/resolv.conf"
 "/etc/rsyslog.conf" "/etc/sensors3.conf" "/etc/sysctl.conf" "/etc/ucf.conf"
 "/etc/updatedb.conf" "/etc/usb_modeswitch.conf" "/etc/wodim.conf")

Using `open-directory` and `get-lines`

(mappend [iff (op ends-with ".conf") list] (get-lines (open-directory "/etc")))

Output:

("ddclient.conf" "gai.conf" "ucf.conf" "kernel-img.conf" "ltrace.conf"
 "debconf.conf" "apg.conf" "adduser.conf" "mke2fs.conf" "colord.conf"
 "kerneloops.conf" "fuse.conf" "hdparm.conf" "irssi.conf" "host.conf"
 "ffserver.conf" "pam.conf" "sysctl.conf" "ld.so.conf" "dnsmasq.conf"
 "insserv.conf" "brltty.conf" "deluser.conf" "netscsid.conf" "nsswitch.conf"
 "mtools.conf" "wodim.conf" "updatedb.conf" "popularity-contest.conf"
 "knockd.conf" "ntp.conf" "sensors3.conf" "resolv.conf" "blkid.conf"
 "lftp.conf" "ca-certificates.conf" "usb_modeswitch.conf" "logrotate.conf"
 "rsyslog.conf" "pnm2ppa.conf")

UNIX Shell

ls -d *.c                # *.c files in current directory
(cd mydir && ls -d *.c)  # *.c files in mydir

*.c is a file name pattern, also known as a glob pattern. The shell expands each pattern to a sorted list of matching files. Details are in your shell's manual.

If there are no *.c files, ls fails with an error message.

UnixPipes

Here using grep for regexp.

ls | grep '\.c$'

VBScript

Sub show_files(folder_path,pattern)
	Set objfso = CreateObject("Scripting.FileSystemObject")
	For Each file In objfso.GetFolder(folder_path).Files
		If InStr(file.Name,pattern) Then
			WScript.StdOut.WriteLine file.Name
		End If
	Next
End Sub

Call show_files("C:\Windows",".exe")

Visual Basic .NET

Works with: Visual Basic .NET version 9.0+

'Using the OS pattern matching
For Each file In IO.Directory.GetFiles("\temp", "*.txt")
  Console.WriteLine(file)
Next
 
'Using VB's pattern matching and LINQ
For Each file In (From name In IO.Directory.GetFiles("\temp") Where name Like "*.txt")
  Console.WriteLine(file)
Next
 
'Using VB's pattern matching and dot-notation
For Each file In IO.Directory.GetFiles("\temp").Where(Function(f) f Like "*.txt")
  Console.WriteLine(file)
Next

Wren

Library: Wren-pattern

import "io" for Directory
import "./pattern" for Pattern

var walk = Fn.new { |dir, pattern|
    if (!Directory.exists(dir)) Fiber.abort("Directory does not exist.")
    var files = Directory.list(dir)
    return files.where { |f| pattern.isMatch(f) }
}

// get all C header files beginning with 'a' or 'b'
var p = Pattern.new("[a|b]+0^..h", Pattern.whole)
for (f in walk.call("/usr/include", p)) System.print(f)

Output:

aio.h
aliases.h
alloca.h
ar.h
argp.h
argz.h
asoundlib.h
assert.h
byteswap.h

zkl

Unix glob, with wildcarding and options on file type, case folding and a few others.

File.glob("*.zkl") //--> list of matches

Zsh

Zsh has powerful filename generation features, which can filter by file names, permissions, size, type, etc.

print -l -- *.c