ORIGIN 'betaenv'; LIB_DEF 'file' '../lib'; BODY 'private/filebody'; (* * COPYRIGHT * Copyright (C) Mjolner Informatics, 1984-96 * All rights reserved. * * The BETA interface to disk-entries in a hierarchic file system * files, and directories is organised as follows: * * DiskEntry: Machine independent interface to entries like * file and directories on the disk * (file 'file.bet'). * UnixEntry: Unix specific specialization of DiskEntry * (file 'unixfile.bet'). * MacEntry: Macintosh specific specialization of DiskEntry * (file 'macfile.bet'). * * File: Machine independent interface to disk files. Is * a specialization of Stream (file 'betaenv.bet'), * and contains a DiskEntry (file 'file.bet'). * UnixFile: Unix specific specialization of File, which * contains a UnixEntry (file 'unixfile.bet'). * MacFile: Macintosh specific specialization of File, * which contains a MacEntry (file 'macfile.bet'). * * Directory: Machine independent interface to * directories/folders. Contains a DiskEntry * (file 'directory.bet'). * UnixDirectory: Unix specific specialization of Directory, * which contains a UnixEntry * (file 'unixdirectory.bet'). * MacDirectory: Macintosh specific specialization of Directory, * which contains a MacEntry * (file 'macdirectory.bet'). *) -- LIB: Attributes -- DiskEntry: (* Pattern describing various attributes of disk-entries like files * and directories in a hierarchic file system *) (# <<SLOT DiskEntryLib: attributes>>; (* DISK ENTRY EXCEPTIONS *) DiskEntryException: Exception (* General exception for disk entries *) (# ... #); DiskEntryExistsException: DiskEntryException (* Raised if a test for disk entry existence has * failed. Message: "Test for disk entry existence failed.", * and an indication of why it failed. *) (# ... #); DiskEntryModtimeException: DiskEntryException (* Raised if examination or setting of disk entry modtime has failed. * Message: "Examination/setting of disk entry modtime failed.", and an * indication of why it failed. *) (# ... #); DiskEntryTouchException: DiskEntryException (* Raised if touch of a disk entry has failed. Message: "Touch * of disk entry failed.", and an indication of why it failed. *) (# ... #); DiskEntryRenameException: DiskEntryException (* Raised if rename of a disk entry has failed. Message: * "Rename of disk entry failed.", and an indication of why it * failed. *) (# ... #); pathDesc:< (* A virtual descriptor for the full or relative path of * THIS(DiskEntry) *) (# head:< (* The head of the path, e.g. head of '/usr/smith/foo.bet' * is '/usr/smith' *) (# h: ^text ... exit h[] #); nameDesc:< (* The actual name-part of the path, e.g. name part of * '/usr/smith/foo.bet' is 'foo.bet' *) (# prefix:< (* exits the prefix part of the name, i.e. what is * before the last dot (.), e.g 'foo' for 'foo.bet' *) (# p: ^text ... exit p[] #); extension:< (* exits the extension part of the name, i.e. what * is after the last dot (.), e.g. 'bet' for 'foo.bet' *) (# e: ^text ... exit e[] #); suffix:< (* like extension, but includes the dot (.), * e.g. '.bet' for 'foo.bet' *) (# s: ^text ... exit s[] #); get:< (* exits "prefix.extension" *) (# n: ^text ... exit n[] #); exit get #); name: @nameDesc; set:< (* set the entire path *) (# p: ^text enter p[] ... #); get:< (* get the entire path *) (# p: ^text ... exit p[] #); enter set do INNER exit get #); path: @pathDesc; exists: BooleanValue (* exits a boolean indicating whether the disk entry * corresponding to the current setting of path actually exists *) (# error:< DiskEntryExistsException; ... #); modtime: (* exits an integer denoting the (system) time of the last * modification *) (# time: @integer; error:<DiskEntryModTimeException; enter (# enter time ... #) exit (# ... exit time #) #); touch: (* Updates the modtime to the current (system) time. *) (# error:< DiskEntryTouchException; ... #); rename: (* Rename the disk entry. Changes the physical disk entry and * updates THIS(DiskEntry).path *) (# newpath: ^text; error:< DiskEntryRenameException; enter newpath[] ... #); size: IntegerValue (* exits the size of THIS(DiskEntry) in bytes *) (# error:<DiskEntryException; ... #); readable: BooleanValue (* exits true if THIS(DiskEntry) can be read *) (# error:< DiskEntryException; ... #); writeable: BooleanValue (* exits true if THIS(DiskEntry) can be written to *) (# error:< DiskEntryException; checkwrite: @...; do checkwrite #); isFile: BooleanValue (* True if THIS(DiskEntry) is a regular file *) (# error:< DiskEntryException; ... #); isDirectory: BooleanValue (* True if THIS(DiskEntry) is a directory *) (# error:<DiskEntryException; ... #); private: @... do INNER #); (* DiskEntry *) (* Constants used for specifying mode to File.SetPos. *) FromBeginning: (* Seeks relative to the beginning of a file. Corresponds to * absolute positions in File[0:File.Length-1]. *) (# exit 0 #); FromCurrent: (* Seeks relative to the current position. *) (# exit 1 #); FromEnd: (* Seeks relative to the end of a file. *) (# exit 2 #); File: Stream (* Generalization of disk file. Describes the stream aspects of * files, providing buffered I/O, and contains a DiskEntry object * describing the other properties of a file. *) (# <<SLOT FileLib: attributes>>; EntryDesc:< DiskEntry; Entry: @EntryDesc (* The item holding most characterizing attributes of * THIS(file) *); name: @ (* convenient interface to entry.path *) (# read: (* Reads the file name from the Keyboard *) (# ... #); enter entry.path exit entry.path #); Put::< (# ... #); Get::< (# ... #); Peek::< (# ... #); PutText::< (# ... #); GetAtom::< (# ... #); GetLine::< (# ... #); Length::< (* Returns the byte size of THIS(file). Notice that this is * not always the same as entry.size, which is how many bytes * THIS(file) occupies on the disk *) (# ... #); GetPos::< (* Returns current position of THIS(File) *) (# ... #); SetPos::< (* Sets position on THIS(file). Enters position and mode. See * above for definition of constants to use as mode, * FromBeginning, FromCurrent, FromEnd. Returns the absolute * position seeked to [0..File.Length-1]. *) (# mode,newpos: @integer enter mode ... exit newpos #); Eos::< (# ... #); touch: entry.touch (* If the disk entry does not exist, an empty file will be * created. *) (# ... #); delete: (* Deletes THIS(File) *) (# ... #); binary:< booleanvalue (* THIS(File) is binary if value is true. On some systems a * non-binary (e.g. textual) file may behave differently, than * a binary file. A binary file is always treated as raw bytes, * whereas a non-binary file may treat some characters, notably * the end-of-line marker, differently. *); openRead: (* opens THIS(File) for reading, starting at the beginning *) (# ... #); openWrite: (* Opens THIS(File) for writing. truncates the contents of * the disk file if it already existed, and creates the disk * file if not *) (# ... #); openAppend: (* Opens THIS(File) for writing at the end. Setpos cannot be * used to write other places than at the end. Creates the * file if it did not exist. *) (# ... #); openReadWrite: (* Opens THIS(File) for both reading and writing. The file is * positioned at the beginning. To switch between writing and * reading an intermediate setpos may be necessary. *) (# ... #); openReadAppend: (* Like OpenReadWrite, but positiones at the end *) (# ... #); flush: (* Flushes THIS(File). Affects only files opened for output *) (# ... #); close: (* Closes THIS(File) *) (# ... #); (* FILE EXCEPTIONS *) FileException: StreamException (* General File exception *) (# m: ^text enter m[] ... #); OpenException: FileException (* Raised if opening of a file has failed. Message: "Cannot * open file". *) (# ... #); AccessError:< OpenException (* Raised on attempt to access a file with insufficient * privilegies. Message: "Insufficient access privilegies". *) (# ... #); WriteError:< FileException (* Raised from Put, PutText and Flush on attempt to write on a * non-existing block. Message: "Write block error". *) (# ... #); ReadError:< FileException (* Raised from Get and Peek on attempt to read a non-existing * block. Message: "Read block error". *) (# ... #); EOSerror::< (# ... #); NoSuchFileError:< FileException (* Raised on attempt to open a non-existing file. Message: * "File does not exist" *) (# ... #); FileExistsError:< FileException (* Raised when creating an already existing file. Message: * "File does already exist". *) (# ... #); NoSpaceError:< FileException (* Raised when the file system is full. Message: "File system * is full". *) (# ... #); OtherError:< FileException (* Raised when errors other than the above occur *) (# ... #); private: @ ...; getRep: (* OBSOLETE - only supplied for compatibility. * The operation getBytes from binfile should be used instead. *) (# repAdr (* @@ rep[inx]: start address *), length (* max. no. of elements to read *): @integer; enter(repAdr,length) ... exit(length div 4) #); putRep: (* OBSOLETE - only supplied for compatibility. * The operation putBytes from binfile should be used instead. *) (# repAdr (* @@rep[inx]: start address *), length (* no. of rep-elements to be and was written *): @integer; enter(repAdr,length) ... exit (length div 4) #); #)
| 13.6 File Interface | © 1990-2002 Mjølner Informatics |
[Modified: Sunday August 9th 1998 at 22:18]
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