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diff --git a/filesystem/call_development.rst b/filesystem/call_development.rst new file mode 100644 index 0000000..aafdf52 --- /dev/null +++ b/filesystem/call_development.rst @@ -0,0 +1,1132 @@ +System Call Development Notes +############################# + +This set of routines represents the application’s interface to files and directories +under the RTEMS filesystem. All routines are compliant with POSIX standards if a +specific interface has been established. The list below represents the routines that have +been included as part of the application’s interface. + +# access() + +# chdir() + +# chmod() + +# chown() + +# close() + +# closedir() + +# dup() + +# dup2() + +# fchmod() + +# fcntl() + +# fdatasync() + +# fpathconf() + +# fstat() + +# ioctl() + +# link() + +# lseek() + +# mkdir() + +# mkfifo() + +# mknod() + +# mount() + +# open() + +# opendir() + +# pathconf() + +# read() + +# readdir() + +# unmount() + +The sections that follow provide developmental information concerning each +of these functions. + +.. COMMENT: @page + +access +====== + +**File:** + +access.c + +**Processing:** + +This routine is layered on the stat() function. It acquires the current +status information for the specified file and then determines if the +caller has the ability to access the file for read, write or execute +according to the mode argument to this function. + +**Development Comments:** + +This routine is layered on top of the stat() function. As long as the +st_mode element in the returned structure follow the standard UNIX +conventions, this function should support other filesystems without +alteration. + +.. COMMENT: @page + +chdir +===== + +**File:** + +chdir.c + +**Processing:** + +This routine will determine if the pathname that we are attempting to make +that current directory exists and is in fact a directory. If these +conditions are met the global indication of the current directory +(rtems_filesystem_current) is set to the rtems_filesystem_location_info_t +structure that is returned by the rtems_filesystem_evaluate_path() +routine. + +**Development Comments:** + +This routine is layered on the rtems_filesystem_evaluate_path() routine +and the filesystem specific OP table function node_type(). + +The routine node_type() must be a routine provided for each filesystem +since it must access the filesystems node information to determine which +of the following types the node is: + +- RTEMS_FILESYSTEM_DIRECTORY + +- RTEMS_FILESYSTEM_DEVICE + +- RTEMS_FILESYSTEM_HARD_LINK + +- RTEMS_FILESYSTEM_MEMORY_FILE + +This acknowledges that the form of the node management information can +vary from one filesystem implementation to another. + +RTEMS has a special global structure that maintains the current directory +location. This global variable is of type rtems_filesystem_location_info_t +and is called rtems_filesystem_current. This structure is not always +valid. In order to determine if the structure is valid, you must first +test the node_access element of this structure. If the pointer is NULL, +then the structure does not contain a valid indication of what the current +directory is. + +.. COMMENT: @page + +chmod +===== + +**File:** + +chmod.c + +**Processing:** + +This routine is layered on the open(), fchmod() and close() functions. As +long as the standard interpretation of the mode_t value is maintained, +this routine should not need modification to support other filesystems. + +**Development Comments:** + +The routine first determines if the selected file can be open with +read/write access. This is required to allow modification of the mode +associated with the selected path. + +The fchmod() function is used to actually change the mode of the path +using the integer file descriptor returned by the open() function. + +After mode modification, the open file descriptor is closed. + +.. COMMENT: @page + +chown +===== + +**File:** + +chown.c + +**Processing:** + +This routine is layered on the rtems_filesystem_evaluate_path() and the +file system specific chown() routine that is specified in the OPS table +for the file system. + +**Development Comments:** + +rtems_filesystem_evaluate_path() is used to determine if the path +specified actually exists. If it does a rtems_filesystem_location_info_t +structure will be obtained that allows the shell function to locate the +OPS table that is to be used for this filesystem. + +It is possible that the chown() function that should be in the OPS table +is not defined. A test for a non-NULL OPS table chown() entry is performed +before the function is called. + +If the chown() function is defined in the indicated OPS table, the +function is called with the rtems_filesystem_location_info_t structure +returned from the path evaluation routine, the desired owner, and group +information. + +.. COMMENT: @page + +close +===== + +**File:** + +close.c + +**Processing:** + +This routine will allow for the closing of both network connections and +file system devices. If the file descriptor is associated with a network +device, the appropriate network function handler will be selected from a +table of previously registered network functions (rtems_libio_handlers) +and that function will be invoked. + +If the file descriptor refers to an entry in the filesystem, the +appropriate handler will be selected using information that has been +placed in the file control block for the device (rtems_libio_t structure). + +**Development Comments:** + +rtems_file_descriptor_type examines some of the upper bits of the file +descriptor index. If it finds that the upper bits are set in the file +descriptor index, the device referenced is a network device. + +Network device handlers are obtained from a special registration table +(rtems_libio_handlers) that is set up during network initialization. The +network handler invoked and the status of the network handler will be +returned to the calling process. + +If none of the upper bits are set in the file descriptor index, the file +descriptor refers to an element of the RTEMS filesystem. + +The following sequence will be performed for any filesystem file +descriptor: + +# Use the rtems_libio_iop() function to obtain the rtems_libio_t + structure for the file descriptor + +# Range check the file descriptor using rtems_libio_check_fd() + +# Determine if there is actually a function in the selected handler + table that processes the close() operation for the filesystem and node + type selected. This is generally done to avoid execution attempts on + functions that have not been implemented. + +# If the function has been defined it is invoked with the file control + block pointer as its argument. + +# The file control block that was associated with the open file + descriptor is marked as free using rtems_libio_free(). + +# The return code from the close handler is then passed back to the + calling program. + +.. COMMENT: @page + +closedir +======== + +**File:** + +closedir.c + +**Processing:** + +The code was obtained from the BSD group. This routine must clean up the +memory resources that are required to track an open directory. The code is +layered on the close() function and standard memory free() functions. It +should not require alterations to support other filesystems. + +**Development Comments:** + +The routine alters the file descriptor and the index into the DIR +structure to make it an invalid file descriptor. Apparently the memory +that is about to be freed may still be referenced before it is +reallocated. + +The dd_buf structure’s memory is reallocated before the control structure +that contains the pointer to the dd_buf region. + +DIR control memory is reallocated. + +The close() function is used to free the file descriptor index. + +.. COMMENT: @page + +dup() Unimplemented +======================== + +**File:** + +dup.c + +**Processing:** + +**Development Comments:** + +.. COMMENT: @page + +dup2() Unimplemented +========================= + +**File:** + +dup2.c + +**Processing:** + +**Development Comments:** + +.. COMMENT: @page + +fchmod +====== + +**File:** + +fchmod.c + +**Processing:** + +This routine will alter the permissions of a node in a filesystem. It is +layered on the following functions and macros: + +- rtems_file_descriptor_type() + +- rtems_libio_iop() + +- rtems_libio_check_fd() + +- rtems_libio_check_permissions() + +- fchmod() function that is referenced by the handler table in the + file control block associated with this file descriptor + +**Development Comments:** + +The routine will test to see if the file descriptor index is associated +with a network connection. If it is, an error is returned from this +routine. + +The file descriptor index is used to obtain the associated file control +block. + +The file descriptor value is range checked. + +The file control block is examined to determine if it has write +permissions to allow us to alter the mode of the file. + +A test is made to determine if the handler table that is referenced in the +file control block contains an entry for the fchmod() handler function. If +it does not, an error is returned to the calling routine. + +If the fchmod() handler function exists, it is called with the file +control block and the desired mode as parameters. + +.. COMMENT: @page + +fcntl() +======= + +**File:** + +fcntl.c + +**Processing:** + +This routine currently only interacts with the file control block. If the +structure of the file control block and the associated meanings do not +change, the partial implementation of fcntl() should remain unaltered for +other filesystem implementations. + +**Development Comments:** + +The only commands that have been implemented are the F_GETFD and F_SETFD. +The commands manipulate the LIBIO_FLAGS_CLOSE_ON_EXEC bit in the``flags`` element of the file control block associated with the file +descriptor index. + +The current implementation of the function performs the sequence of +operations below: + +# Test to see if we are trying to operate on a file descriptor + associated with a network connection + +# Obtain the file control block that is associated with the file + descriptor index + +# Perform a range check on the file descriptor index. + +.. COMMENT: @page + +fdatasync +========= + +**File:** + +fdatasync.c + +**Processing:** + +This routine is a template in the in memory filesystem that will route us to the +appropriate handler function to carry out the fdatasync() processing. In the in +memory filesystem this function is not necessary. Its function in a disk based file +system that employs a memory cache is to flush all memory based data buffers to +disk. It is layered on the following functions and macros: + +- rtems_file_descriptor_type() + +- rtems_libio_iop() + +- rtems_libio_check_fd() + +- rtems_libio_check_permissions() + +- fdatasync() function that is referenced by the handler table in the + file control block associated with this file descriptor + +**Development Comments:** + +The routine will test to see if the file descriptor index is associated +with a network connection. If it is, an error is returned from this +routine. + +The file descriptor index is used to obtain the associated file control +block. + +The file descriptor value is range checked. + +The file control block is examined to determine if it has write +permissions to the file. + +A test is made to determine if the handler table that is referenced in the +file control block contains an entry for the fdatasync() handler function. +If it does not an error is returned to the calling routine. + +If the fdatasync() handler function exists, it is called with the file +control block as its parameter. + +.. COMMENT: @page + +fpathconf +========= + +**File:** + +fpathconf.c + +**Processing:** + +This routine is layered on the following functions and macros: + +- rtems_file_descriptor_type() + +- rtems_libio_iop() + +- rtems_libio_check_fd() + +- rtems_libio_check_permissions() + +When a filesystem is mounted, a set of constants is specified for the +filesystem. These constants are stored with the mount table entry for the +filesystem. These constants appear in the POSIX standard and are listed +below. + +- PCLINKMAX + +- PCMAXCANON + +- PCMAXINPUT + +- PCNAMEMAX + +- PCPATHMAX + +- PCPIPEBUF + +- PCCHOWNRESTRICTED + +- PCNOTRUNC + +- PCVDISABLE + +- PCASYNCIO + +- PCPRIOIO + +- PCSYNCIO + +This routine will find the mount table information associated the file +control block for the specified file descriptor parameter. The mount table +entry structure contains a set of filesystem specific constants that can +be accessed by individual identifiers. + +**Development Comments:** + +The routine will test to see if the file descriptor index is associated +with a network connection. If it is, an error is returned from this +routine. + +The file descriptor index is used to obtain the associated file control +block. + +The file descriptor value is range checked. + +The file control block is examined to determine if it has read permissions +to the file. + +Pathinfo in the file control block is used to locate the mount table entry +for the filesystem associated with the file descriptor. + +The mount table entry contains the pathconf_limits_and_options element. +This element is a table of constants that is associated with the +filesystem. + +The name argument is used to reference the desired constant from the +pathconf_limits_and_options table. + +.. COMMENT: @page + +fstat +===== + +**File:** + +fstat.c + +**Processing:** + +This routine will return information concerning a file or network +connection. If the file descriptor is associated with a network +connection, the current implementation of ``fstat()`` will return a +mode set to ``S_IFSOCK``. In a later version, this routine will map the +status of a network connection to an external handler routine. + +If the file descriptor is associated with a node under a filesystem, the +fstat() routine will map to the fstat() function taken from the node +handler table. + +**Development Comments:** + +This routine validates that the struct stat pointer is not NULL so that +the return location is valid. + +The struct stat is then initialized to all zeros. + +rtems_file_descriptor_type() is then used to determine if the file +descriptor is associated with a network connection. If it is, network +status processing is performed. In the current implementation, the file +descriptor type processing needs to be improved. It currently just drops +into the normal processing for file system nodes. + +If the file descriptor is associated with a node under a filesystem, the +following steps are performed: + +# Obtain the file control block that is associated with the file descriptor + index. + +# Range check the file descriptor index. + +# Test to see if there is a non-NULL function pointer in the handler + table for the fstat() function. If there is, invoke the function with the + file control block and the pointer to the stat structure. + +.. COMMENT: @page + +ioctl +===== + +**File:** + +ioctl.c + +**Processing:** + +Not defined in the POSIX 1003.1b standard but commonly supported in most +UNIX and POSIX system. Ioctl() is a catchall for I/O operations. Routine +is layered on external network handlers and filesystem specific handlers. +The development of new filesystems should not alter the basic processing +performed by this routine. + +**Development Comments:** + +The file descriptor is examined to determine if it is associated with a +network device. If it is processing is mapped to an external network +handler. The value returned by this handler is then returned to the +calling program. + +File descriptors that are associated with a filesystem undergo the +following processing: + +# The file descriptor index is used to obtain the associated file + control block. + +# The file descriptor value is range checked. + +# A test is made to determine if the handler table that is referenced + in the file control block contains an entry for the ioctl() handler + function. If it does not, an error is returned to the calling routine. + +# If the ioctl() handler function exists, it is called with the file + control block, the command and buffer as its parameters. + +# The return code from this function is then sent to the calling + routine. + +.. COMMENT: @page + +link +==== + +**File:** + +link.c + +**Processing:** + +This routine will establish a hard link to a file, directory or a device. +The target of the hard link must be in the same filesystem as the new link +being created. A link to an existing link is also permitted but the +existing link is evaluated before the new link is made. This implies that +links to links are reduced to links to files, directories or devices +before they are made. + +**Development Comments:** + +Calling parameters: +const char \*existing +const char \*new + +link() will determine if the target of the link actually exists using +rtems_filesystem_evaluate_path() + +rtems_filesystem_get_start_loc() is used to determine where to start the +path evaluation of the new name. This macro examines the first characters +of the name to see if the name of the new link starts with a +rtems_filesystem_is_separator. If it does the search starts from the root +of the RTEMS filesystem; otherwise the search will start from the current +directory. + +The OPS table evalformake() function for the parent’s filesystem is used +to locate the node that will be the parent of the new link. It will also +locate the start of the new path’s name. This name will be used to define +a child under the parent directory. + +If the parent is found, the routine will determine if the hard link that +we are trying to create will cross a filesystem boundary. This is not +permitted for hard-links. + +If the hard-link does not cross a filesystem boundary, a check is +performed to determine if the OPS table contains an entry for the link() +function. + +If a link() function is defined, the OPS table link() function will be +called to establish the actual link within the filesystem. + +The return code from the OPS table link() function is returned to the +calling program. + +.. COMMENT: @page + +lseek +===== + +**File:** + +lseek.c + +**Processing:** + +This routine is layered on both external handlers and filesystem / node +type specific handlers. This routine should allow for the support of new +filesystems without modification. + +**Development Comments:** + +This routine will determine if the file descriptor is associated with a +network device. If it is lseek will map to an external network handler. +The handler will be called with the file descriptor, offset and whence as +its calling parameters. The return code from the external handler will be +returned to the calling routine. + +If the file descriptor is not associated with a network connection, it is +associated with a node in a filesystem. The following steps will be +performed for filesystem nodes: + +# The file descriptor is used to obtain the file control block for the + node. + +# The file descriptor is range checked. + +# The offset element of the file control block is altered as indicated + by the offset and whence calling parameters + +# The handler table in the file control block is examined to determine + if it contains an entry for the lseek() function. If it does not an error + is returned to the calling program. + +# The lseek() function from the designated handler table is called + with the file control block, offset and whence as calling arguments + +# The return code from the lseek() handler function is returned to the + calling program + +.. COMMENT: @page + +mkdir +===== + +**File:** + +mkdir.c + +**Processing:** + +This routine attempts to create a directory node under the filesystem. The +routine is layered the mknod() function. + +**Development Comments:** + +See mknod() for developmental comments. + +.. COMMENT: @page + +mkfifo +====== + +**File:** + +mkfifo.c + +**Processing:** + +This routine attempts to create a FIFO node under the filesystem. The +routine is layered the mknod() function. + +**Development Comments:** + +See mknod() for developmental comments + +.. COMMENT: @page + +mknod +===== + +**File:** + +mknod.c + +**Processing:** + +This function will allow for the creation of the following types of nodes +under the filesystem: + +- directories + +- regular files + +- character devices + +- block devices + +- fifos + +At the present time, an attempt to create a FIFO will result in an ENOTSUP +error to the calling function. This routine is layered the filesystem +specific routines evalformake and mknod. The introduction of a new +filesystem must include its own evalformake and mknod function to support +the generic mknod() function. Under this condition the generic mknod() +function should accommodate other filesystem types without alteration. + +**Development Comments:** + +Test for nodal types - I thought that this test should look like the +following code: +.. code:: c + + if ( (mode & S_IFDIR) = = S_IFDIR) \|| + (mode & S_IFREG) = = S_IFREG) \|| + (mode & S_IFCHR) = = S_IFCHR) \|| + (mode & S_IFBLK) = = S_IFBLK) \|| + (mode & S_IFIFO) = = S_IFIFO)) + Set_errno_and_return_minus_one (EINVAL); + +Where: + +- S_IFREG (0100000) - Creation of a regular file + +- S_IFCHR (0020000) - Creation of a character device + +- S_IFBLK (0060000) - Creation of a block device + +- S_IFIFO (0010000) - Creation of a FIFO + +Determine if the pathname that we are trying to create starts at the root +directory or is relative to the current directory using the +rtems_filesystem_get_start_loc() function. + +Determine if the pathname leads to a valid directory that can be accessed +for the creation of a node. + +If the pathname is a valid location to create a node, verify that a +filesystem specific mknod() function exists. + +If the mknod() function exists, call the filesystem specific mknod() +function. Pass the name, mode, device type and the location information +associated with the directory under which the node will be created. + +.. COMMENT: @page + +mount +===== + +**File:** + +mount.c + +Arguments (Not a standard POSIX call): + +rtems_filesystem_mount_table_entry_t \**mt_entry, + +If the mount operation is successful, this pointer to a pointer will be +set to reference the mount table chain entry that has been allocated for +this file system mount. + +rtems_filesystem_operations_table \*fs_ops, + +This is a pointer to a table of functions that are associated with the +file system that we are about to mount. This is the mechanism to selected +file system type without keeping a dynamic database of all possible file +system types that are valid for the mount operation. Using this method, it +is only necessary to configure the filesystems that we wish to use into +the RTEMS build. Unused filesystems types will not be drawn into the +build. + +char \*fsoptions, + +This argument points to a string that selects mounting for read only +access or read/write access. Valid states are "RO" and "RW" + +char \*device, + +This argument is reserved for the name of a device that will be used to +access the filesystem information. Current filesystem implementations are +memory based and do not require a device to access filesystem information. + +char \*mount_point + +This is a pathname to a directory in a currently mounted filesystem that +allows read, write and execute permissions. If successful, the node found +by evaluating this name, is stored in the mt_entry. + +**Processing:** + +This routine will handle the mounting of a filesystem on a mount point. If +the operation is successful, a pointer to the mount table chain entry +associated with the mounted filesystem will be returned to the calling +function. The specifics about the processing required at the mount point +and within the filesystem being mounted is isolated in the filesystem +specific mount() and fsmount_me() functions. This allows the generic +mount() function to remain unaltered even if new filesystem types are +introduced. + +**Development Comments:** + +This routine will use get_file_system_options() to determine if the mount +options are valid ("RO" or "RW"). + +It confirms that a filesystem ops-table has been selected. + +Space is allocated for a mount table entry and selective elements of the +temporary mount table entry are initialized. + +If a mount point is specified: The mount point is examined to determine +that it is a directory and also has the appropriate permissions to allow a +filesystem to be mounted. + +The current mount table chain is searched to determine that there is not +another filesystem mounted at the mount point we are trying to mount onto. + +If a mount function is defined in the ops table for the filesystem +containing the mount point, it is called at this time. + +If no mount point is specified: Processing if performed to set up the +mount table chain entry as the base filesystem. + +If the fsmount_me() function is specified for ops-table of the filesystem +being mounted, that function is called to initialize for the new +filesystem. + +On successful completion, the temporary mount table entry will be placed +on the mount table chain to record the presence of the mounted filesystem. + +.. COMMENT: @page + +open +==== + +**File:** + +open.c + +**Processing:** + +This routine is layered on both RTEMS calls and filesystem specific +implementations of the open() function. These functional interfaces should +not change for new filesystems and therefore this code should be stable as +new file systems are introduced. + +**Development Comments:** + +This routine will allocate a file control block for the file or device +that we are about to open. + +It will then test to see if the pathname exists. If it does a +rtems_filesystem_location_info_t data structure will be filled out. This +structure contains information that associates node information, +filesystem specific functions and mount table chain information with the +pathname. + +If the create option has been it will attempt to create a node for a +regular file along the specified path. If a file already exists along this +path, an error will be generated; otherwise, a node will be allocated for +the file under the filesystem that contains the pathname. When a new node +is created, it is also evaluated so that an appropriate +rtems_filesystem_location_info_t data structure can be filled out for the +newly created node. + +If the file exists or the new file was created successfully, the file +control block structure will be initialized with handler table +information, node information and the rtems_filesystem_location_info_t +data structure that describes the node and filesystem data in detail. + +If an open() function exists in the filesystem specific handlers table for +the node that we are trying to open, it will be called at this time. + +If any error is detected in the process, cleanup is performed. It consists +of freeing the file control block structure that was allocated at the +beginning of the generic open() routine. + +On a successful open(), the index into the file descriptor table will be +calculated and returned to the calling routine. + +.. COMMENT: @page + +opendir +======= + +**File:** + +opendir.c + +**Processing:** + +This routine will attempt to open a directory for read access. It will +setup a DIR control structure that will be used to access directory +information. This routine is layered on the generic open() routine and +filesystem specific directory processing routines. + +**Development Comments:** + +The BSD group provided this routine. + +.. COMMENT: @page + +pathconf +======== + +**File:** + +pathconf.c + +**Processing:** + +This routine will obtain the value of one of the path configuration +parameters and return it to the calling routine. It is layered on the +generic open() and fpathconf() functions. These interfaces should not +change with the addition of new filesystem types. + +**Development Comments:** + +This routine will try to open the file indicated by path. + +If successful, the file descriptor will be used to access the pathconf +value specified by ``name`` using the fpathconf() function. + +The file that was accessed is then closed. + +.. COMMENT: @page + +read +==== + +**File:** + +deviceio.c + +**Processing:** + +This routine is layered on a set of RTEMS calls and filesystem specific +read operations. The functions are layered in such a way as to isolate +them from change as new filesystems are introduced. + +**Development Comments:** + +This routine will examine the type of file descriptor it is sent. + +If the file descriptor is associated with a network device, the read +function will be mapped to a special network handler. The return code from +the network handler will then be sent as the return code from generic +read() function. + +For file descriptors that are associated with the filesystem the following +sequence will be performed: + +# Obtain the file control block associated with the file descriptor + +# Range check the file descriptor + +# Determine that the buffer pointer is not invalid + +# Check that the count is not zero + +# Check the file control block to see if we have permissions to read + +# If there is a read function in the handler table, invoke the handler + table read() function + +# Use the return code from the handler table read function(number of + bytes read) to increment the offset element of the file control block + +# Return the number of bytes read to the calling program + +.. COMMENT: @page + +readdir +======= + +**File:** + +readdir.c + +**Processing:** + +This routine was acquired from the BSD group. It has not been altered from +its original form. + +**Development Comments:** + +The routine calls a customized getdents() function that is provided by the +user. This routine provides the filesystem specific aspects of reading a +directory. + +It is layered on the read() function in the directory handler table. This +function has been mapped to the Imfs_dir_read() function. + +.. COMMENT: @page + +unmount +======= + +**File:** + +unmount.c + +**Processing:** + +This routine will attempt to dismount a mounted filesystem and then free +all resources that were allocated for the management of that filesystem. + +**Development Comments:** + +- This routine will determine if there are any filesystems currently + mounted under the filesystem that we are trying to dismount. This would + prevent the dismount of the filesystem. + +- It will test to see if the current directory is in the filesystem + that we are attempting to dismount. This would prevent the dismount of the + filesystem. + +- It will scan all the currently open file descriptors to determine is + there is an open file descriptor to a file in the filesystem that we are + attempting to unmount(). + +If the above preconditions are met then the following sequence is +performed: + +# Call the filesystem specific unmount() function for the filesystem + that contains the mount point. This routine should indicate that the mount + point no longer has a filesystem mounted below it. + +# Call the filesystem specific fsunmount_me() function for the mounted + filesystem that we are trying to unmount(). This routine should clean up + any resources that are no longer needed for the management of the file + system being un-mounted. + +# Extract the mount table entry for the filesystem that was just + dismounted from the mount table chain. + +# Free the memory associated with the extracted mount table entry. + +.. COMMENT: @page + +eval +==== + +**File:** + +XXX + +**Processing:** + +XXX + +**Development Comments:** + +XXX + +.. COMMENT: @page + +getdentsc +========= + +**File:** + +XXX + +**Processing:** + +XXX + +**Development Comments:** + +XXX + +.. COMMENT: COPYRIGHT (c) 1988-2002. + +.. COMMENT: On-Line Applications Research Corporation (OAR). + +.. COMMENT: All rights reserved. + |