Resources(3)

NAME
Mac::Resources - Macintosh Toolbox Interface to the Resource Manager

SYNOPSIS
    use Mac::Memory;
    use Mac::Resources;

DESCRIPTION
Access to Inside Macintosh is essential for proper use of these functions. Explanations of terms, processes and procedures are provided there. Any attempt to use these functions without guidance can cause severe errors in your machine, including corruption of data. You have been warned.

  Constants

resSysHeap
resPurgeable
resLocked
resProtected
resPreload
resChanged
    Resource flags.

mapReadOnly
mapCompact
mapChanged
    Resource map flags.

kResFileNotOpened
    Returned after an unsuccessful call to "OpenResFile()".

kSystemResFile
    The resource file reference number of the system file.

  Functions

CloseResFile RFD
    Given a file reference number for a file whose resource fork is open, the CloseResFile procedure performs four tasks. First, it updates the file by calling the &UpdateResFile procedure. Second, it releases the memory occupied by each resource in the resource fork by calling the &DisposeHandle procedure. Third, it releases the memory occupied by the resource map. The fourth task is to close the resource fork.

CurResFile
    The CurResFile function returns the file reference number associated with the current resource file. You can call this function when your application starts up (before opening the resource fork of any other file) to get the file reference number of your application's resource fork.

        $RFD = CurResFile;

HomeResFile RESOURCE
    Given a handle to a resource, the HomeResFile function returns the file reference number for the resource fork containing the specified resource. If the given handle isn't a handle to a resource, HomeResFile returns D-1, and the &ResError function returns the result code resNotFound. If HomeResFile returns 0, the resource is in the System file's resource fork. If HomeResFile returns 1, the resource is ROM-resident.

        $RFD = HomeResFile($Resource);

CreateResFile NAME
    Mac OS only.

    The CreateResFile procedure creates an empty resource file.

        if ( CreateResFile("Resource.rsrc")) {
            # error occurred
        } else {
            # proceed
        }

OpenResFile NAME
    Mac OS only.

    The OpenResFile function opens an existing resource file. It also makes this file the current resource file.

        if ( defined($RFD = OpenResFile("Resource.rsrc")) ) {
            # proceed
        } else {
            # error occurred
        }

UseResFile RFD
    The UseResFile procedure searches the list of files whose resource forks have been opened for the file specified by the RFD parameter. If the specified file is found, the Resource Manager sets the current resource file to the specified file. If there's no resource fork open for a file with that reference number, UseResFile does nothing. To set the current resource file to the System file, use 0 for the refNum parameter.

        if (UseResFile($RFD)) {
            # error occurred
        } else {
            # proceed
        }

CountTypes
Count1Types
    The CountTypes (Count1Types) function reads the resource maps in memory for all resource forks (the current resource fork) open to your application. It returns an integer representing the total number of unique resource types.

        $types = Count1Types;

GetIndType INDEX
Get1IndType INDEX
    Given an index number from 1 to the number of resource types in all resource forks (the current resource fork) open to your application (as returned by CountTypes), the GetIndType procedure returns a resource type. You can call GetIndType repeatedly over the entire range of the index to get all the resource types available in all resource forks open to your application. If the given index isn't in the range from 1 to the number of resource types as returned by CountTypes, undef() is returned.

        # Load up @resourceTypes with the types from the current file.
        for (1 .. Count1Types) {
            $resourceTypes[$_-1] = Get1IndType($_);
        }

SetResLoad BOOL
    Enable and disable automatic loading of resource data into memory for routines that return handles to resources.

CountResources TYPE
Count1Resources TYPE
    Get the total number of available resources of a given type. Count1Resources looks only at the current resource fork.

        $totalDialogsAvailable = CountResources "DITL";

GetIndResource TYPE, INDEX
Get1IndResource TYPE, INDEX
    Given an index ranging from 1 to the number of resources of a given type returned by &CountResources (&Count1Resources) (that is, the number of resources of that type in all resource forks open to your application), the GetIndResource function returns a handle to a resource of the given type. If you call GetIndResource repeatedly over the entire range of the index, it returns handles to all resources of the given type in all resource forks open to your application.

        # Load up handles of this type of resource
        for (1 .. CountResources("DITL")) {
            $dialogs[$_] = GetIndResource("DITL", $_);
        }

GetResource TYPE, ID
Get1Resource TYPE, ID
    Get resource data for a resource specified by resource type and resource ID.

        $SFGdialog = GetResource("DITL", 6042);
        if ( defined $SFGdialog ) {
            # proceed
        }

GetNamedResource TYPE, NAME
Get1NamedResource TYPE, NAME
    The GetNamedResource (Get1NamedResource) function searches the resource maps in memory for the resource specified by the parameters $TYPE and $NAME.

        $SFGdialog = GetNamedResource("DITL", "Standard Get");
        if ( defined $SFGdialog ) {
            # proceed
        }

LoadResource HANDLE
    Given a handle to a resource, LoadResource reads the resource data into memory. If the HANDLE parameter doesn't contain a handle to a resource, then LoadResource returns undef.

        if (LoadResource($HANDLE) ) {
            # proceed
        } else {
            # error occurred
        }

ReleaseResource HANDLE
    Given a handle to a resource, ReleaseResource releases the memory occupied by the resource data, if any, and sets the master pointer of the resource's handle in the resource map in memory to NIL. If your application previously obtained a handle to that resource, the handle is no longer valid. If your application subsequently calls the Resource Manager to get the released resource, the Resource Manager assigns a new handle.

        if ( ReleaseResource($HANDLE) ) {
            # proceed
        } else {
            # error occurred
        }

DetachResource HANDLE
    Given a handle to a resource, ReleaseResource releases the memory occupied by the resource data, if any, and sets the master pointer of the resource's handle in the resource map in memory to NIL. If your application previously obtained a handle to that resource, the handle is no longer valid. If your application subsequently calls the Resource Manager to get the released resource, the Resource Manager assigns a new handle.

        if ( DetachResource($HANDLE) ) {
            # proceed
        } else {
            # error occurred
        }

UniqueID TYPE
Unique1ID TYPE
    The UniqueID function returns as its function result a resource ID greater than 0 that isn't currently assigned to any resource of the specified type in any open resource fork. You should use this function before adding a new resource to ensure that you don't duplicate a resource ID and override an existing resource. Unique1ID ensures uniqueness within the current resource fork.

        $id = Unique1ID("DITL");

GetResAttrs HANDLE
    Given a handle to a resource, the GetResAttrs function returns the resource's attributes as recorded in its entry in the resource map in memory. If the value of the theResource parameter isn't a handle to a valid resource, undef is returned.

        $resAttrs = GetResAttrs($HANDLE);
        if ( defined $resAttrs ) {
            # proceed
        }

GetResInfo HANDLE
    Given a handle to a resource, the GetResInfo procedure returns the resource's resource ID, resource type, and resource name. If the handle isn't a valid handle to a resource, undef is returned.

        ($id, $type, $name) = GetResInfo($HANDLE);
        if ( defined $id ) {
            # proceed
        }

SetResInfo HANDLE, ID, NAME
    Given a handle to a resource, SetResInfo changes the resource ID and the resource name of the specified resource to the values given in ID and NAME. If you pass an empty string for the name parameter, the resource name is not changed.

AddResource HANDLE, TYPE, ID, NAME
    Given a handle to any type of data in memory (but not a handle to an existing resource), AddResource adds the given handle, resource type, resource ID, and resource name to the current resource file's resource map in memory. The AddResource procedure sets the resChanged attribute to 1; it does not set any of the resource's other attributesN~that is, all other attributes are set to 0.

GetResourceSizeOnDisk HANDLE
    Given a handle to a resource, the GetResourceSizeOnDisk function checks the resource on disk (not in memory) and returns its exact size, in bytes. If the handle isn't a handle to a valid resource, undef is returned.

            $size = GetResourceSizeOnDisk($HANDLE);
            if ( defined $size ) {
                    # proceed
            }

GetMaxResourceSize HANDLE
    Like &GetResourceSizeOnDisk, GetMaxResourceSize takes a handle and returns the size of the corresponding resource. However, GetMaxResourceSize does not check the resource on disk; instead, it either checks the resource size in memory or, if the resource is not in memory, calculates its size, in bytes, on the basis of information in the resource map in memory. This gives you an approximate size for the resource that you can count on as the resource's maximum size. It's possible that the resource is actually smaller than the offsets in the resource map indicate because the file has not yet been compacted. If you want the exact size of a resource on disk, either call &GetResourceSizeOnDisk or call &UpdateResFile before calling GetMaxResourceSize.

        $size = GetMaxResourceSize($HANDLE);
        if ( defined $size ) {
            # proceed
        }

RsrcMapEntry HANDLE
    Mac OS only.

    Given a handle to a resource, RsrcMapEntry returns the offset of the specified resource's entry from the beginning of the resource map in memory. If it doesn't find the resource entry, RsrcMapEntry returns 0, and the ResError function returns the result code resNotFound. If you pass a handle whose value is NIL, RsrcMapEntry returns arbitrary data.

        $offset = RsrcMapEntry($HANDLE);
        if ( defined $offset ) {
            # proceed
        }

SetResAttrs HANDLE, ATTRS
    Given a handle to a resource, SetResAttrs changes the resource attributes of the resource to those specified in the attrs parameter. The SetResAttrs procedure changes the information in the resource map in memory, not in the file on disk. The resProtected attribute changes immediately. Other attribute changes take effect the next time the specified resource is read into memory but are not made permanent until the Resource Manager updates the resource fork.

        if ( SetResAttrs($HANDLE, $ATTRS) ) {
            # proceed
        } else {
            # error
        }

ChangedResource HANDLE
    Given a handle to a resource, the ChangedResource procedure sets the resChanged attribute for that resource in the resource map in memory. If the resChanged attribute for a resource has been set and your application calls &UpdateResFile or quits, the Resource Manager writes the resource data for that resource (and for all other resources whose resChanged attribute is set) and the entire resource map to the resource fork of the corresponding file on disk. If the resChanged attribute for a resource has been set and your application calls &WriteResource, the Resource Manager writes only the resource data for that resource to disk.

        if ( ChangedResource($HANDLE) ) {
            # proceed
        } else {
            # error
        }

RemoveResource HANDLE
    Given a handle to a resource in the current resource file, RemoveResource removes the resource entry (resource type, resource ID, resource name, if any, and resource attributes) from the current resource file's resource map in memory.

        if ( RemoveResource($HANDLE) ) {
            # proceed
        } else {
            # error
        }

UpdateResFile RFD
    Given the reference number of a file whose resource fork is open, UpdateResFile performs three tasks. The first task is to change, add, or remove resource data in the file's resource fork to match the resource map in memory. Changed resource data for each resource is written only if that resource's resChanged bit has been set by a successful call to &ChangedResource or &AddResource. The UpdateResFile procedure calls the &WriteResource procedure to write changed or added resources to the resource fork.

        if ( UpdateResFile($RFD) ) {
            # proceed
        } else {
            # error
        }

WriteResource HANDLE
    Given a handle to a resource, WriteResource checks the resChanged attribute of that resource. If the resChanged attribute is set to 1 (after a successful call to the &ChangedResource or &AddResource procedure), WriteResource writes the resource data in memory to the resource fork, then clears the resChanged attribute in the resource's resource map in memory.

        if ( WriteResource($HANDLE) ) {
            # proceed
        } else {
            # error
        }

SetResPurge INSTALL
    Specify TRUE in the install parameter to make the Memory Manager pass the handle for a resource to the Resource Manager before purging the resource data to which the handle points. The Resource Manager determines whether the handle points to a resource in the application heap. It also checks if the resource's resChanged attribute is set to 1. If these two conditions are met, the Resource Manager calls the &WriteResource procedure to write the resource's resource data to the resource fork before returning control to the Memory Manager.

    Specify FALSE in the install parameter to restore the normal state, so that the Memory Manager purges resource data when it needs to without calling the Resource Manager.

        if ( SetResPurge(1) ) {
            # proceed
        } else {
            # error
        }

GetResFileAttrs RFD
    Given a file reference number, the GetResFileAttrs function returns the attributes of the file's resource fork. Specify 0 in $RFD to get the attributes of the System file's resource fork. If there's no open resource fork for the given file reference number, undef is returned.

        $rfa = GetResFileAttrs($RFD);
        if ( defined $rfa ) {
            # proceed
        }

SetResFileAttrs RFD, ATTRS
    Given a file reference number, the SetResFileAttrs procedure sets the attributes of the file's resource fork to those specified in the attrs parameter. If the refNum parameter is 0, it represents the System file's resource fork. However, you shouldn't change the attributes of the System file's resource fork. If there's no resource fork with the given reference number, SetResFileAttrs does nothing, and the ResError function returns the result code noErr.

        if ( SetResFileAttrs($RFD, $ATTRS) ) {
            # proceed
        } else {
            # error
        }

RGetResource TYPE, ID
    Mac OS only.

    The RGetResource function searches the resource maps in memory for the resource specified by the parameters $TYPE and $ID. The resource maps in memory, which represent all open resource forks, are arranged as a linked list. The RGetResource function first uses GetResource to search this list. The GetResource function starts with the current resource file and progresses through the list in order (that is, in reverse chronological order in which the resource forks were opened) until it finds the resource's entry in one of the resource maps. If GetResource doesn't find the specified resource in its search of the resource maps of open resource forks (which includes the System file's resource fork), RGetResource sets the global variable RomMapInsert to TRUE, then calls GetResource again. In response, GetResource performs the same search, but this time it looks in the resource map of the ROM-resident resources before searching the resource map of the System file.

        $handle = RGetResource("DITL", 6042);
        if ( defined $handle ) {
            # proceed
        }

FSpOpenResFile SPEC, PERMISSION
    The FSpOpenResFile function opens the resource fork of the file identified by the spec parameter. It also makes this file the current resource file.

        $sp = FSpOpenResFile($SPEC);
        if ( defined $sp ) {
            # proceed
        }

    In addition to opening the resource fork for the file with the specified name, FSpOpenResFile lets you specify in the permission parameter the read/write permission of the resource fork the first time it is opened.

FSOpenResourceFile REF, FORKNAME, PERMISSION
    Mac OS X only.

    The FSOpenResourceFile function is like FSpOpenResFile, except that it can open a resource file using the data fork or resource fork. $REF is the path to the resource file. $FORKNAME is "rsrc" for a resource fork; else the data fork will be used. It also makes this file the current resource file.

FSpCreateResFile SPEC, CREATOR, FILETYPE, SCRIPTTAG
    The FSpCreateResFile procedure creates an empty resource fork for a file with the specified $FILETYPE, $CREATOR, and $SCRIPTTAG in the location and with the name designated by the spec parameter. (An empty resource fork contains no resource data but does include a resource map.)

        if ( FSpCreateResFile($SPEC, $CREATOR, $FILETYPE, $SCRIPTTAG) ) {
            # proceed
        } else {
            # error
        }

FSCreateResourceFile PARENTREF, FILENAME, FORKNAME
    Mac OS X only.

    The FSCreateResourceFile procedure is like FSpCreateResFile, except that it can create a resource file in the data fork or resource fork. $PARENTREF is the oath of the directory where the new $FILENAME will be located. $FORKNAME is "rsrc" for a resource fork; else the data fork will be used.

ReadPartialResource HANDLE, OFFSET, BYTECOUNT
    The ReadPartialResource procedure reads the resource subsection identified by the theResource, offset, and count parameters.

        $data = ReadPartialResource($rsrc, 2000, 256);

WritePartialResource HANDLE, OFFSET, DATA
    The WritePartialResource procedure writes the data specified by DATA to the resource subsection identified by the HANDLE and OFFSET parameters.

        if ( WritePartialResource($HANDLE, $OFFSET, $DATA) ) {
            # proceed
        } else {
            # error
        }

SetResourceSize HANDLE, SIZE
    Given a handle to a resource, SetResourceSize sets the size field of the specified resource on disk without writing the resource data. You can change the size of any resource, regardless of the amount of memory you have available.

        if ( SetResource($HANDLE, $SIZE) ) {
            # proceed
        } else {
            # error
        }

AUTHOR
Written by Matthias Ulrich Neeracher <neeracher@mac.com>, documentation by Bob Dalgleish <bob.dalgleish@sasknet.sk.ca>. Currently maintained by Chris Nandor <pudge@pobox.com>.

POD ERRORS
Hey! The above document had some coding errors, which are explained below:

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