Retired Document
Important: This sample code may not represent best practices for current development. The project may use deprecated symbols and illustrate technologies and techniques that are no longer recommended.
FullPath.c
/* |
File: FullPath.c |
Contains: Routines for dealing with full pathnames... if you really must. |
Written by: |
Copyright: Copyright © 1995-1999 by Apple Computer, Inc., All Rights Reserved. |
You may incorporate this Apple sample source code into your program(s) without |
restriction. This Apple sample source code has been provided "AS IS" and the |
responsibility for its operation is yours. You are not permitted to redistribute |
this Apple sample source code as "Apple sample source code" after having made |
changes. If you're going to re-distribute the source, we require that you make |
it clear in the source that the code was descended from Apple sample source |
code, but that you've made changes. |
Change History (most recent first): |
8/3/1999 Karl Groethe Updated for Metrowerks Codewarror Pro 2.1 |
*/ |
#include <Types.h> |
#include <Errors.h> |
#include <Memory.h> |
#include <Files.h> |
#include <TextUtils.h> |
#include <Aliases.h> |
#include "FSpCompat.h" |
#include "FullPath.h" |
#define __COMPILINGMOREFILES |
/* |
IMPORTANT NOTE: |
The use of full pathnames is strongly discouraged. Full pathnames are |
particularly unreliable as a means of identifying files, directories |
or volumes within your application, for two primary reasons: |
¥ The user can change the name of any element in the path at virtually |
any time. |
¥ Volume names on the Macintosh are *not* unique. Multiple |
mounted volumes can have the same name. For this reason, the use of |
a full pathname to identify a specific volume may not produce the |
results you expect. If more than one volume has the same name and |
a full pathname is used, the File Manager currently uses the first |
mounted volume it finds with a matching name in the volume queue. |
In general, you should use a fileÕs name, parent directory ID, and |
volume reference number to identify a file you want to open, delete, |
or otherwise manipulate. |
If you need to remember the location of a particular file across |
subsequent system boots, use the Alias Manager to create an alias record |
describing the file. If the Alias Manager is not available, you can save |
the fileÕs name, its parent directory ID, and the name of the volume on |
which itÕs located. Although none of these methods is foolproof, they are |
much more reliable than using full pathnames to identify files. |
Nonetheless, it is sometimes useful to display a fileÕs full pathname to |
the user. For example, a backup utility might display a list of full |
pathnames of files as it copies them onto the backup medium. Or, a |
utility might want to display a dialog box showing the full pathname of |
a file when it needs the userÕs confirmation to delete the file. No |
matter how unreliable full pathnames may be from a file-specification |
viewpoint, users understand them more readily than volume reference |
numbers or directory IDs. (Hint: Use the TruncString function from |
TextUtils.h with truncMiddle as the truncWhere argument to shorten |
full pathnames to a displayable length.) |
The following technique for constructing the full pathname of a file is |
intended for display purposes only. Applications that depend on any |
particular structure of a full pathname are likely to fail on alternate |
foreign file systems or under future system software versions. |
*/ |
/*****************************************************************************/ |
pascal OSErr GetFullPath(short vRefNum, |
long dirID, |
ConstStr255Param name, |
short *fullPathLength, |
Handle *fullPath) |
{ |
OSErr result; |
FSSpec spec; |
*fullPathLength = 0; |
*fullPath = NULL; |
result = FSMakeFSSpecCompat(vRefNum, dirID, name, &spec); |
if ( result == noErr ) |
{ |
result = FSpGetFullPath(&spec, fullPathLength, fullPath); |
} |
return ( result ); |
} |
/*****************************************************************************/ |
pascal OSErr FSpGetFullPath(const FSSpec *spec, |
short *fullPathLength, |
Handle *fullPath) |
{ |
OSErr result; |
FSSpec tempSpec; |
CInfoPBRec pb; |
*fullPathLength = 0; |
*fullPath = NULL; |
/* Make a copy of the input FSSpec that can be modified */ |
BlockMoveData(spec, &tempSpec, sizeof(FSSpec)); |
if ( tempSpec.parID == fsRtParID ) |
{ |
/* The object is a volume */ |
/* Add a colon to make it a full pathname */ |
++tempSpec.name[0]; |
tempSpec.name[tempSpec.name[0]] = ':'; |
/* We're done */ |
result = PtrToHand(&tempSpec.name[1], fullPath, tempSpec.name[0]); |
} |
else |
{ |
/* The object isn't a volume */ |
/* Is the object a file or a directory? */ |
pb.dirInfo.ioNamePtr = tempSpec.name; |
pb.dirInfo.ioVRefNum = tempSpec.vRefNum; |
pb.dirInfo.ioDrDirID = tempSpec.parID; |
pb.dirInfo.ioFDirIndex = 0; |
result = PBGetCatInfoSync(&pb); |
if ( result == noErr ) |
{ |
/* if the object is a directory, append a colon so full pathname ends with colon */ |
if ( (pb.hFileInfo.ioFlAttrib & ioDirMask) != 0 ) |
{ |
++tempSpec.name[0]; |
tempSpec.name[tempSpec.name[0]] = ':'; |
} |
/* Put the object name in first */ |
result = PtrToHand(&tempSpec.name[1], fullPath, tempSpec.name[0]); |
if ( result == noErr ) |
{ |
/* Get the ancestor directory names */ |
pb.dirInfo.ioNamePtr = tempSpec.name; |
pb.dirInfo.ioVRefNum = tempSpec.vRefNum; |
pb.dirInfo.ioDrParID = tempSpec.parID; |
do /* loop until we have an error or find the root directory */ |
{ |
pb.dirInfo.ioFDirIndex = -1; |
pb.dirInfo.ioDrDirID = pb.dirInfo.ioDrParID; |
result = PBGetCatInfoSync(&pb); |
if ( result == noErr ) |
{ |
/* Append colon to directory name */ |
++tempSpec.name[0]; |
tempSpec.name[tempSpec.name[0]] = ':'; |
/* Add directory name to beginning of fullPath */ |
(void) Munger(*fullPath, 0, NULL, 0, &tempSpec.name[1], tempSpec.name[0]); |
result = MemError(); |
} |
} while ( (result == noErr) && (pb.dirInfo.ioDrDirID != fsRtDirID) ); |
} |
} |
} |
if ( result == noErr ) |
{ |
/* Return the length */ |
*fullPathLength = GetHandleSize(*fullPath); |
} |
else |
{ |
/* Dispose of the handle and return NULL and zero length */ |
if ( *fullPath != NULL ) |
{ |
DisposeHandle(*fullPath); |
} |
*fullPath = NULL; |
*fullPathLength = 0; |
} |
return ( result ); |
} |
/*****************************************************************************/ |
pascal OSErr FSpLocationFromFullPath(short fullPathLength, |
const void *fullPath, |
FSSpec *spec) |
{ |
AliasHandle alias; |
OSErr result; |
Boolean wasChanged; |
Str32 nullString; |
/* Create a minimal alias from the full pathname */ |
nullString[0] = 0; /* null string to indicate no zone or server name */ |
result = NewAliasMinimalFromFullPath(fullPathLength, fullPath, nullString, nullString, &alias); |
if ( result == noErr ) |
{ |
/* Let the Alias Manager resolve the alias. */ |
result = ResolveAlias(NULL, alias, spec, &wasChanged); |
DisposeHandle((Handle)alias); /* Free up memory used */ |
} |
return ( result ); |
} |
/*****************************************************************************/ |
pascal OSErr LocationFromFullPath(short fullPathLength, |
const void *fullPath, |
short *vRefNum, |
long *parID, |
Str31 name) |
{ |
OSErr result; |
FSSpec spec; |
result = FSpLocationFromFullPath(fullPathLength, fullPath, &spec); |
if ( result == noErr ) |
{ |
*vRefNum = spec.vRefNum; |
*parID = spec.parID; |
BlockMoveData(&spec.name[0], &name[0], spec.name[0] + 1); |
} |
return ( result ); |
} |
/*****************************************************************************/ |
Copyright © 2003 Apple Computer, Inc. All Rights Reserved. Terms of Use | Privacy Policy | Updated: 2003-01-14