Locating macOS significant directories

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Revision as of 06:29, 29 July 2020 by Trev (talk | contribs) (→‎Get significant directories function: Updated GetSignificantDir with suggestion by ChrisR)
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This article applies to macOS only.

See also: Multiplatform Programming Guide

│ English (en) │

Overview

To locate various significant directories in macOS you can use the native macOS Foundation function 

NSSearchPathForDirectoriesInDomains(NSSearchPathDirectory directory, NSSearchPathDomainMask domainMask, BOOL expandTilde);

which creates a list of path strings for the specified directories in the specified domains. The list is in the order in which you should search the directories.

Note: The directory returned by this method may not exist. This method simply gives you the appropriate location for the requested directory. Depending on the application’s needs, it may be up to the developer to create the appropriate directory and any in between.

Determining where to store files

Before we go any further, let's recap where the Apple Guidelines indicate your application should store its files:

  • Use the /Applications or /Applications/Utilities directory for the application bundle. The application bundle should contain everything: libraries, dependencies, help, every file that the application needs to run except those created by the application itself. If the application bundle is copied to another machine's /Applications or /Applications/Utilities directory, it should be able to run. Installing to these folders requires Admin privileges. The data in these folders is backed up by Time Machine.
  • Use the ~/Applications directory should Admin privileges not be available. This is the standard location for a single user application. This directory should not be expected to exist. The application bundle should contain everything: libraries, dependencies, help, every file that the application needs to run except those created by the application itself. If the application bundle is copied to another machine's /Applications or /Applications/Utilities directory, it should be able to run. This data is backed up by Time Machine.
  • Use the Application Support directory (this data is backed up by Time Machine), appending your <bundle_ID>, for:
    • Resource and data files that your application creates and manages for the user. You might use this directory to store application state information, computed or downloaded data, or even user created data that you manage on behalf of the user.
    • Autosave files.
  • Use the Caches directory (this is not backed up by Time Machine), appending your <bundle_ID>, for cached data files or any files that your application can recreate easily.
  • Use CFPreferences to read and write your application's preferences. This will automatically write preferences to the appropriate location and read them from the appropriate location. This data is backed up by Time Machine.
  • Use the application Resources directory (this is backed up by Time Machine) for your application-supplied image files, sound files, icon files and other unchanging data files necessary for your application's operation.
  • Use NSTemporaryDirectory (this is not backed up by Time Machine) to store temporary files that you intend to use immediately for some ongoing operation but then plan to discard later. Delete temporary files as soon as you are done with them.

Get significant directories function

...
{$modeswitch objectivec1} 

interface

Uses
  ...
  CocoaUtils,   // for NStringToString
  CocoaAll;     // for NSArray      
...

function GetSignificantDir(DirLocation: qword; DomainMask: qword; count: byte): string;
var
  paths : NSArray;
begin
  paths := NSSearchPathForDirectoriesInDomains(DirLocation, DomainMask, True);
  if(count < paths.count) then
    Result := NSString(paths.objectAtIndex(0)).UTF8String
  else
    Result := '';  
end;

Table of Directory Locations

Directory Locations
Directory name Directory Description
NSApplicationDirectory Supported applications (/Applications)
NSDemoApplicationDirectory Unsupported applications and demonstration versions
NSDeveloperApplicationDirectory Developer applications (/Developer/Applications)
NSAdminApplicationDirectory System and network administration applications
NSLibraryDirectory Various user-visible documentation, support, and configuration files (/Library)
NSDeveloperDirectory Developer resources (/Developer)
NSUserDirectory User home directories (/Users)
NSDocumentationDirectory Documentation
NSDocumentDirectory Document directory
NSCoreServiceDirectory Core services (System/Library/CoreServices)
NSAutosavedInformationDirectory The user’s autosaved documents (Library/Autosave Information)
NSDesktopDirectory The user’s desktop directory
NSCachesDirectory Discardable cache files (Library/Caches)
NSApplicationSupportDirectory Application support files (Library/Application Support)
NSDownloadsDirectory The user’s downloads directory
NSInputMethodsDirectory Input Methods (Library/Input Methods)
NSMoviesDirectory The user’s Movies directory (~/Movies)
NSMusicDirectory The user’s Music directory (~/Music)
NSPicturesDirectory The user’s Pictures directory (~/Pictures)
NSPrinterDescriptionDirectory The system’s PPDs directory (Library/Printers/PPDs)
NSSharedPublicDirectory The user’s Public sharing directory (~/Public)
NSPreferencePanesDirectory The PreferencePanes directory for use with System Preferences (Library/PreferencePanes)
NSApplicationScriptsDirectory The user scripts folder for the calling application (~/Library/Application Scripts/<code-signing-id>
NSItemReplacementDirectory The constant used to create a temporary directory
NSAllApplicationsDirectory All directories where applications can be stored
NSAllLibrariesDirectory All directories where resources can be stored
NSTrashDirectory The user's trash directory

Table of Path Domains

Path Domains
Domain name Domain Description
NSUserDomainMask The user’s home directory—the place to install user’s personal items (~).
NSLocalDomainMask The place to install items available to everyone on this machine
NSNetworkDomainMask The place to install items available on the network (/Network)
NSSystemDomainMask A directory for system files provided by Apple (/System)
NSAllDomainsMask All domains


Code Examples

You can now locate various significant directories and display them as demonstrated by the code examples below.

User caches directory

procedure TForm1.MenuItem5Click(Sender: TObject);
begin
  ShowMessage('User caches dir: ' + GetSignificantDir(NSCachesDirectory,NSUserDomainMask,0));
end;

User trash directory

procedure TForm1.MenuItem16Click(Sender: TObject);
begin
  ShowMessage('User trash dir: '
          + GetSignificantDir(NSTrashDirectory,NSUserDomainMask,0));
end;

Users directory

Maybe not what you expect... this is the /Users directory :-) 

procedure TForm1.MenuItem10Click(Sender: TObject);
begin
  ShowMessage('Users dir: ' +  GetSignificantDir(NSUserDirectory,NSLocalDomainMask,0));
end;

To retrieve the current user's home directory, you need to use the NSHomeDirectory() function instead: 

procedure TForm1.MenuItem11Click(Sender: TObject);
begin
  ShowMessage('User''s dir: ' + NSStringToString(NSHomeDirectory));
end;

All application directories

procedure TForm1.MenuItem7Click(Sender: TObject);
var
  count: byte;
begin
  for count := 0 to 12 do
   if GetSignificantDir(NSAllApplicationsDirectory, NSAllDomainsMask, count) <> '' then
      ShowMessage('Application dir ' + IntToStr(count) + ': '
           + GetSignificantDir(NSAllApplicationsDirectory,NSAllDomainsMask,count))
   else
      exit; 
end;

All user application directories

procedure TForm1.MenuItem8Click(Sender: TObject);
var
  count: byte;
begin
  for count := 0 to 12 do
   if GetSignificantDir(NSAllApplicationsDirectory, NSUserDomainMask, count) <> '' then
      ShowMessage('User application dir ' + IntToStr(count) + ': '
           + GetSignificantDir(NSAllApplicationsDirectory,NSUserDomainMask,count))
   else
      exit; 
end;

All system application directories

procedure TForm1.MenuItem9Click(Sender: TObject);
var
  count: byte;
begin
  for count := 0 to 12 do
   if GetSignificantDir(NSAllApplicationsDirectory, NSSystemDomainMask, count) <> '' then
      ShowMessage('System application dir ' + IntToStr(count) + ': '
           + GetSignificantDir(NSAllApplicationsDirectory,NSSystemDomainMask,count))
   else
      exit; 
end;

Replacements for FPC's GetAppConfigDir and GetAppConfigFile

The existing FPC GetAppConfigDir and GetAppConfigFile functions are not macOS friendly because they use the UNIX convention and not the Apple macOS convention. For example, the output from these functions: 

writeLn(GetAppConfigDir(true));
writeLn(GetAppConfigDir(false));

writeLn(GetAppConfigFile(true));
writeLn(GetAppConfigFile(false));

writeLn(GetAppConfigFile(true,true));
writeLn(GetAppConfigFile(true,false));

writeLn(GetAppConfigFile(false,false));
writeLn(GetAppConfigFile(false,true));

is this: 

/etc/
/Users/<username>/.config/

/etc/project1.cfg
/Users/<username>/.config/project1.cfg

/etc/project1/project1.cfg
/etc/project1.cfg

/Users/<username>/.config/project1.cfg
/Users/<username>/.config/project1/project1.cfg

whereas the correct output for a macOS command line application (ie without an Application Bundle) is: 

/Library/Application Support/project1/
/Users/<username>/Library/Application Support/project1/

/Library/Application Support/project1/project1.plist
/Users/<username>/Library/Application Support/project1/project1.plist

/Library/Application Support/project1/project1.plist
/Library/Application Support/project1/project1.plist

/Users/<username>/Library/Application Support/project1/project1.plist
/Users/<username>/Library/Application Support/project1/project1.plist

and the correct output for a macOS GUI application (ie with an Application Bundle): 

/Library/Application Support/com.company.project1/
/Users/<username>/Library/Application Support/com.company.project1/

/Library/Application Support/com.company.project1/project1.plist
/Users/<username>/Library/Application Support/com.company.project1/project1.plist

/Library/Application Support/com.company.project1/project1.plist
/Library/Application Support/com.company.project1/project1.plist

/Users/<username>/Library/Application Support/com.company.project1/project1.plist
/Users/<username>/Library/Application Support/com.company.project1/project1.plist

Here are the replacement functions -- named with the addition of a 2 to the existing function names -- and with ${IFDEF}s so that they can be used in multi-platform code: 

{$mode objfpc}{H+}
{$modeswitch objectivec1}

...

Uses
  CocoaAll, MacOSAll, SysUtils;

...

//
// GetAppConfigDir Replacement
//

function GetAppConfigDir2(Global: Boolean): String;

{$IFDEF DARWIN}
var
  bundleIdStr: ShortString;
  pathBuffer: PChar;
  pathsArr : NSArray;
  status: Boolean;
{$ENDIF}
begin
  {$IFDEF DARWIN}
  try
     pathBuffer := AllocMem(MAX_PATH);
  except on exception
     do exit;
  end;

  try
    try
    status := CFStringGetPascalString(CFStringRef(CFBundleGetIdentifier(CFBundleGetMainBundle)),@bundleIdStr,255,CFStringGetSystemEncoding);
    except on exception do
      bundleIdStr := ExtractFileName(paramstr(0)); // Handle non-bundled apps eg command line
    end;

    if(Global) then
       pathsArr := NSSearchPathForDirectoriesInDomains(NSApplicationSupportDirectory, NSLocalDomainMask, True)
    else
      pathsArr := NSSearchPathForDirectoriesInDomains(NSApplicationSupportDirectory, NSUserDomainMask, True);

    status := CFStringGetCString(CFStringRef(pathsArr.objectAtIndex(0)),pathBuffer,MAX_PATH,CFStringGetSystemEncoding);
    if(status) then
      Result := pathBuffer + '/' + bundleIdStr + '/'
    else
      Result := '';
  finally
      FreeMem(pathBuffer);
  end

  {$ELSE}
    GetAppConfigDir(global);
  {$ENDIF}
end;

//    
// GetAppConfigFile replacement
//

Function GetAppConfigFile2(Global : Boolean; SubDir : Boolean) : String;

{$IFDEF DARWIN}
var
  bundleIdStr: ShortString;
  appNameStr: ShortString;
  pathBufferStr: String;
  isAppBundle : Boolean = True;
{$ENDIF}
begin
  {$IFDEF DARWIN}
  try
    CFStringGetPascalString(CFStringRef(CFBundleGetIdentifier(CFBundleGetMainBundle)),@bundleIdStr,255,CFStringGetSystemEncoding);
  except on exception do
    begin
    // Handle non-bundled apps eg command line
    bundleIdStr := ExtractFileName(paramstr(0));
    isAppBundle := False;
    end;
  end;

  pathBufferStr := GetAppConfigDir2(Global);

  if(isAppBundle) then
    appNameStr := StringReplace(ExtractFileExt(bundleIdStr), '.', '', [rfReplaceAll])
  else
    appNameStr := extractFileName(ExcludeTrailingPathDelimiter(pathBufferStr));

  if(SubDir) then
    // Ignore because Apple dictates the subdir already as part of GetAppConfigDir()
    ;

  Result := pathBufferStr + appNameStr + '.plist';

  {$ELSE}
  Result := GetAppConfigFile(Global, SubDir);
  {$ENDIF}
end;

//
// GetAppConfigFile replacement
//

Function GetAppConfigFile2(Global : Boolean) : String;

{$IFDEF DARWIN}
var
  bundleIdStr: ShortString;
  appNameStr: ShortString;
  pathBufferStr : String;
  isAppBundle   : Boolean = True;
{$ENDIF}
begin
  {$IFDEF DARWIN}
  try
    CFStringGetPascalString(CFStringRef(CFBundleGetIdentifier(CFBundleGetMainBundle)),@bundleIdStr,255,CFStringGetSystemEncoding);
  except on exception do
    begin
      // Handle non-bundled apps eg command line
      bundleIdStr := ExtractFileName(paramstr(0));
      isAppBundle := False;
    end;
  end;

  pathBufferStr := GetAppConfigDir2(Global);

  if(isAppBundle) then
    appNameStr := StringReplace(ExtractFileExt(bundleIdStr), '.', '', [rfReplaceAll])
  else
    appNameStr := extractFileName(ExcludeTrailingPathDelimiter(pathBufferStr));

  Result := GetAppConfigDir2(Global) + appNameStr + '.plist';
  {$ELSE}
  Result := GetAppConfigFile(Global);
  {$ENDIF}
end;
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