QB64-PE/internal/help/FILES.txt

The {{KW|FILES}} statement is used to return a list of files in the current directory using a filespec, but long lists will scroll the screen.


{{PageSyntax}}
:{{KW|FILES}} [{{Parameter|fileSpec$}}]


{{PageDescription}}

* Filespec is a string expression or variable containing a path when required.
* Filespec can use the * and ? wildcard specs like normal DOS DIR statements.
: * denotes one or more wildcard characters in a filename or path spec as any legal file name  character(s).
: ? denotes one wildcard letter in a filename or path spec as any legal filename character. 
* If {{Parameter|fileSpec$}} is omitted, it is assumed to be <code>"*.*"</code> (all files and folders in the current directory).
* Illegal filename characters in '''QB64''' include * > < : " | \ / with any amount of dot extensions being allowed in Windows.
* Illegal filename characters in '''Qbasic''' include * ? , > < ; : " | \ / + [ ] and more than one dot extension in [http://www.computerhope.com/issues/ch000209.htm DOS].
* FILES lists can make the screen roll. Try using SHELL "DIR" with the /P option. [http://www.computerhope.com/dirhlp.htm DIR command].



''Example 1:'' Finding a list of all BAS files in the current folder. 
{{CodeStart}}{{Cl|FILES}} "*.BAS"
{{CodeEnd}}
<center>'''[http://i301.photobucket.com/albums/nn53/burger2227/FILESss.jpg Screenshot shows only the end of a long list of files]'''</center>


''Example 2:'' A function that verifies that a file exists if it is NOT empty. Note: Function WILL deleted empty files!
{{CodeStart}} '' ''
{{Cl|INPUT}} "Enter a file name: ", file$
{{Cl|IF}} Exist%(file$) {{Cl|THEN}} {{Cl|OPEN}} file$ {{Cl|FOR (file statement)|FOR}} {{Cl|INPUT (file mode)|INPUT}} {{Cl|AS}} #1: found% = -1   'function call demo
{{Cl|CLOSE}} #1
{{Cl|IF}} found% THEN {{Cl|PRINT}} "File exists!" {{Cl|ELSE}} {{Cl|PRINT}} "File not found!"
{{Cl|END}}

{{Cl|FUNCTION}} Exist% (filename$)
f% = {{Cl|FREEFILE}}
{{Cl|OPEN}} filename$ {{Cl|FOR (file statement)|FOR}} {{Cl|APPEND}} {{Cl|AS}} #f%
{{Cl|IF}} {{Cl|LOF}}(f%) {{Cl|THEN}} Exist% = -1 {{Cl|ELSE}} Exist% = 0: {{Cl|CLOSE}} #f%: {{Cl|KILL}} filename$ 'delete empty files
{{Cl|CLOSE}} #f% 
{{Cl|END FUNCTION}} '' ''
{{CodeEnd}}{{small|Code by Ted Weissgerber}}


''Example 3:'' The DIR$ function used in PDS(7.1) returns a filename or a list when more than one exist. The file spec can use a path and/or wildcards.
{{CodeStart}} '' ''
{{Cl|FOR...NEXT|FOR}} i = 1 {{Cl|TO}} 2
  {{Cl|PRINT}}
  {{Cl|LINE INPUT}} "Enter a file spec: ", spec$
  file$ = DIR$(spec$) 'use a file spec ONCE to find the last file name listed
  {{Cl|PRINT}} DIRCount%, file$, 'function can return the file count using {{Cl|SHARED}} variable
  {{Cl|IF...THEN|IF}} DIRCount% > 1 {{Cl|THEN}}
    DO
      K$ = {{Cl|INPUT$}}(1)
      file$ = DIR$("") 'use an empty string parameter to return a list of files!
      {{Cl|PRINT}} file$,
    {{Cl|LOOP}} {{Cl|UNTIL}} {{Cl|LEN}}(file$) = 0 'file list ends with an empty string
  {{Cl|END IF}}
{{Cl|NEXT}}

{{Cl|END}}

{{Cl|FUNCTION}} DIR$ (spec$)
{{Cl|CONST}} TmpFile$ = "DIR$INF0.INF", ListMAX% = 500 'change maximum to suit your needs
{{Cl|SHARED}} DIRCount% 'returns file count if desired
{{Cl|STATIC}} Ready%, Index%, DirList$()
{{Cl|IF...THEN|IF}} {{Cl|NOT}} Ready% {{Cl|THEN}} {{Cl|REDIM}} DirList$(ListMAX%): Ready% = -1 '{{Cl|DIM}} array first use
{{Cl|IF...THEN|IF}} spec$ > "" {{Cl|THEN}} 'get file names when a spec is given
  {{Cl|SHELL}} {{Cl|_HIDE}} "DIR " + spec$ + " /b > " + TmpFile$
  Index% = 0: DirList$(Index%) = "": ff% = {{Cl|FREEFILE}}
  {{Cl|OPEN}} TmpFile$ {{Cl|FOR...NEXT|FOR}} {{Cl|APPEND}} {{Cl|AS}} #ff%
  size& = {{Cl|LOF}}(ff%)
  {{Cl|CLOSE}} #ff%
  {{Cl|IF...THEN|IF}} size& = 0 {{Cl|THEN}} {{Cl|KILL}} TmpFile$: {{Cl|EXIT FUNCTION}}
  {{Cl|OPEN}} TmpFile$ {{Cl|FOR (file statement)|FOR}} {{Cl|INPUT (file mode)|INPUT}} {{Cl|AS}} #ff%
  {{Cl|DO...LOOP|DO}} {{Cl|WHILE}} {{Cl|NOT}} {{Cl|EOF}}(ff%) {{Cl|AND (boolean)|AND}} Index% < ListMAX%
    Index% = Index% + 1
    {{Cl|LINE INPUT (file statement)|LINE INPUT}} #ff%, DirList$(Index%)
  {{Cl|LOOP}}
  DIRCount% = Index% '{{Cl|SHARED}} variable can return the file count
  {{Cl|CLOSE}} #ff%
  {{Cl|KILL}} TmpFile$
{{Cl|ELSE}} {{Cl|IF...THEN|IF}} Index% > 0 {{Cl|THEN}} Index% = Index% - 1 'no spec sends next file name
{{Cl|END IF}}
DIR$ = DirList$(Index%)
{{Cl|END FUNCTION}} '' ''
{{CodeEnd}}
{{small|Code by Ted Weissgerber}}
:''Explanation:'' The function will verify that a file exists (even if it is empty) by returning it's name or it returns an empty string if no file exists. It can return a list of file names by using an empty string parameter("") after sending a wildcard spec to get the first file name. The number of file names found is returned by using the SHARED variable, '''DIRCount%'''. Unlike the PDS DIR$ function, '''it MUST use an empty string parameter until QB64 supports optional parameters!''' The function does NOT delete empty files.


<center>'''Alternative File List Solution'''</center>
A member created a [[FILELIST$ (function)]] that uses the mouse and does not affect your program screens. It can verify that a file name exists or display a list of long and short file names to choose from. It also avoids program errors when a file name does not exist.   

<center>NEW expanded code is available here: [[FILELIST$]]</center>

<center>[http://i301.photobucket.com/albums/nn53/burger2227/FILE-ss2.jpg FILELIST$ function Screenshot]</center>


''See Library:'' File Exist C++ Function that does not create a temp file. [http://qb64.net/wiki/index.php?title=C_Libraries#File_Exist FileExist Function] 

{{PageSeeAlso}}
* [[SHELL]], [[SCREEN (function)]] {{text|(See Example 2)}}
* [[CHDIR]], [[MKDIR]]
* [[RMDIR]], [[KILL]]
* [[_FILEEXISTS]], [[_DIREXISTS]]
* [[DOS]], [[Batch Files]], [[DOS#DIR|DIR]]
* [[Windows_Libraries#File_Exist|Windows File Exist Library]]
* [[Windows_Libraries#File_Open_and_Save_Dialog|Windows Open and Save Dialog Boxes]]
* [[C_Libraries#Console_Window|C Console Library]]


{{PageNavigation}}