pjs/lib/mac/MoreFiles/FullPath.h

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C

/*
** Apple Macintosh Developer Technical Support
**
** Routines for dealing with full pathnames... if you really must.
**
** by Jim Luther, Apple Developer Technical Support Emeritus
**
** File: FullPath.h
**
** Copyright © 1995-1998 Apple Computer, Inc.
** All rights reserved.
**
** You may incorporate this sample code into your applications without
** restriction, though the sample code has been provided "AS IS" and the
** responsibility for its operation is 100% yours. However, what you are
** not permitted to do is to redistribute the source as "DSC Sample 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 Code, but that you've made changes.
*/
#ifndef __FULLPATH__
#define __FULLPATH__
#include <Types.h>
#include <Files.h>
#include "Optimization.h"
#ifdef __cplusplus
extern "C" {
#endif
/*
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);
/* ¦ Get a full pathname to a volume, directory or file.
The GetFullPath function builds a full pathname to the specified
object. The full pathname is returned in the newly created handle
fullPath and the length of the full pathname is returned in
fullPathLength. Your program is responsible for disposing of the
fullPath handle.
Note that a full pathname can be made to a file/directory that does not
yet exist if all directories up to that file/directory exist. In this case,
GetFullPath will return a fnfErr.
vRefNum input: Volume specification.
dirID input: Directory ID.
name input: Pointer to object name, or nil when dirID
specifies a directory that's the object.
fullPathLength output: The number of characters in the full pathname.
If the function fails to create a full
pathname, it sets fullPathLength to 0.
fullPath output: A handle to the newly created full pathname
buffer. If the function fails to create a
full pathname, it sets fullPath to NULL.
Result Codes
noErr 0 No error
nsvErr -35 No such volume
ioErr -36 I/O error
bdNamErr -37 Bad filename
fnfErr -43 File or directory does not exist (fullPath
and fullPathLength are still valid)
paramErr -50 No default volume
memFullErr -108 Not enough memory
dirNFErr -120 Directory not found or incomplete pathname
afpAccessDenied -5000 User does not have the correct access
afpObjectTypeErr -5025 Directory not found or incomplete pathname
__________
See also: FSpGetFullPath
*/
/*****************************************************************************/
pascal OSErr FSpGetFullPath(const FSSpec *spec,
short *fullPathLength,
Handle *fullPath);
/* ¦ Get a full pathname to a volume, directory or file.
The GetFullPath function builds a full pathname to the specified
object. The full pathname is returned in the newly created handle
fullPath and the length of the full pathname is returned in
fullPathLength. Your program is responsible for disposing of the
fullPath handle.
Note that a full pathname can be made to a file/directory that does not
yet exist if all directories up to that file/directory exist. In this case,
FSpGetFullPath will return a fnfErr.
spec input: An FSSpec record specifying the object.
fullPathLength output: The number of characters in the full pathname.
If the function fails to create a full pathname,
it sets fullPathLength to 0.
fullPath output: A handle to the newly created full pathname
buffer. If the function fails to create a
full pathname, it sets fullPath to NULL.
Result Codes
noErr 0 No error
nsvErr -35 No such volume
ioErr -36 I/O error
bdNamErr -37 Bad filename
fnfErr -43 File or directory does not exist (fullPath
and fullPathLength are still valid)
paramErr -50 No default volume
memFullErr -108 Not enough memory
dirNFErr -120 Directory not found or incomplete pathname
afpAccessDenied -5000 User does not have the correct access
afpObjectTypeErr -5025 Directory not found or incomplete pathname
__________
See also: GetFullPath
*/
/*****************************************************************************/
pascal OSErr FSpLocationFromFullPath(short fullPathLength,
const void *fullPath,
FSSpec *spec);
/* ¦ Get a FSSpec from a full pathname.
The FSpLocationFromFullPath function returns a FSSpec to the object
specified by full pathname. This function requires the Alias Manager.
fullPathLength input: The number of characters in the full pathname
of the target.
fullPath input: A pointer to a buffer that contains the full
pathname of the target. The full pathname
starts with the name of the volume, includes
all of the directory names in the path to the
target, and ends with the target name.
spec output: An FSSpec record specifying the object.
Result Codes
noErr 0 No error
nsvErr -35 The volume is not mounted
fnfErr -43 Target not found, but volume and parent
directory found
paramErr -50 Parameter error
usrCanceledErr -128 The user canceled the operation
__________
See also: LocationFromFullPath
*/
/*****************************************************************************/
pascal OSErr LocationFromFullPath(short fullPathLength,
const void *fullPath,
short *vRefNum,
long *parID,
Str31 name);
/* ¦ Get an object's location from a full pathname.
The LocationFromFullPath function returns the volume reference number,
parent directory ID and name of the object specified by full pathname.
This function requires the Alias Manager.
fullPathLength input: The number of characters in the full pathname
of the target.
fullPath input: A pointer to a buffer that contains the full
pathname of the target. The full pathname starts
with the name of the volume, includes all of
the directory names in the path to the target,
and ends with the target name.
vRefNum output: The volume reference number.
parID output: The parent directory ID of the specified object.
name output: The name of the specified object.
Result Codes
noErr 0 No error
nsvErr -35 The volume is not mounted
fnfErr -43 Target not found, but volume and parent
directory found
paramErr -50 Parameter error
usrCanceledErr -128 The user canceled the operation
__________
See also: FSpLocationFromFullPath
*/
/*****************************************************************************/
#ifdef __cplusplus
}
#endif
#include "OptimizationEnd.h"
#endif /* __FULLPATH__ */