ORIGIN '~beta/basiclib/betaenv'; LIB_DEF 'pathhandler' '../lib'; BODY 'private/pathhandlerbody'; (* * COPYRIGHT * Copyright Mjolner Informatics, 1992-96 * All rights reserved. *) -- LIB: attributes -- (* Utility patterns *) DirectoryChar: (* The character which is used in this operating system to merge local * names to full path-names. Placed here to allow use without having * an instance of pathhandler. *) (# c: @char; ... exit c #); DirectoryCharRegExp: (* The character(s) which are used in this operating system to merge local * names to full path-names. On DOS/Windows this is a regexp that matches * \ or / *) (# t: ^text; ... exit t[] #); IsDirectoryChar: booleanValue (* The difference between this and the above is that on DOS/Windows * both / and \ are valid directory chars, but the canonical one is * \. *) (# c: @char; enter c ... #); CurrentDirectory: (* The current working directory of this process. * Placed here to allow use without having an instance of pathhandler. *) (# cwd: ^text; ... exit cwd[] #); scanSearchPath: (* Scan through a list of paths separated by the delimiter * specified. INNER is called for each path found in * the list. * If pathlist is none, the default search path of the machine. * If delimiter is 0, the default delimiter for searchpaths * is used. *) (# pathlist: ^text; (* list if paths seperated by delimiter *) delimiter: @char; path: ^text; (* pathlist component set before each call of INNER *) enter (pathlist[], delimiter) ... #); applDirectory: (# path: ^text; ... exit path[] #); PathHandler: (* * This pattern converts the Mjolner path notation to and from full native paths. * * The following abbreviations are handled: * * ~ is expanded into the home directory of the user * ~foo is expanded into the home directory of foo * . is interpreted relatively to another path * (see ConvertFilePath below) * .. is interpreted relatively to another path * (see ConvertFilePath below) * * Environment variables like $(HOME) are expanded within paths. * * PathHandler examines the environment variable * * BETALIB. If set, this determines the home directory of the Mjolner * BETA system. * * The value of BETALIB may, but need not, be terminated by '/'. *) (# <<SLOT PathHandlerLib: attributes>>; BetaLib: (* Mjolner BETA System home directory *) (# value: ^text; ... exit value[] #); CurrentDirectory: (* The current working directory of this process *) (# value: ^text; ... exit value[] #); ConvertFilePath:< (* Convert the 'path' relative to 'basis'. * * Within 'path' the conversion expands the abbreviations mentioned * above. '..' is a relative path designating the parent of a directory * (if any) whereas '.' is a relative path designating the directory * itself. If path starts with ~, this is expanded to the home * directory of the user, and if it starts with ~foo, this is expanded * to the home directory of the user foo. These expansions ignore basis. * These abbreviations are only expanded if they are the first * component(s) of 'path'. * * The only meaningful abbreviation in 'basis' is that it may start with * '.' Using this, 'basis' may be specified as the relative path '.' * instead of the absolute path THIS(PathHandler).CurrentDirectory. * * If both the path and the basis are relative paths, the result will be * a relative path, otherwise it will be an absolute path. Path and * basis may be terminated by '/', but need not be. * * The resulting path will contian the native DirectoryChar as separators. * *) (# path,basis, convertedpath: ^text; NoFather:< Exception (* Raised if there are too many '..' in the beginning of 'path' * compared to the given (absolute) basis. * If basis is relative, excess '..'s will be converted to '..' *) (# ... #); convert: @... enter(path[],basis[]) do convert; INNER exit convertedpath[] #); DirectoryChar: @char (* The character which is used in this operating system to merge local * names to full path-names; '/' in unix, ':' on Macintosh, '\' on Windows *); LocalPath: (* Given a path and a basis, exit the local path relative to the basis, * if possible. * * The local path will be a path relative to basis, if basis is a prefix * of path. If this is not the case, it is attempted to use some of the * paths allready converted by THIS(PathHandler) as prefix to path. In * this case the result may be a relative path, or it may be a path in * the form ~foo. If it is not possible to find any legal prefix, the * exception LocalPathException is raised and the original path is * exited. LocalPathException has the continue attribute set to true by * default; set it to false in a further binding, if you want to catch * this error. * * The resulting path will contain '/' as separators. *) (# path,basis: ^text; localName: ^text; LocalPathException:< Exception (# ... #); localize: @...; enter (path[],basis[]) do localize exit localName[] #); init:< (# ... #); Private: @...; #); FilenameConverter: PathHandler (# (* This pathhandler is capable of keeping track of files which have * allready been "converted". * * convertFilePath will return the same pathname every time the same * file is accessed even if the absolute path-names differs. * * E.g. if /users/beta/basiclib/current is a link to the directory * ~cn/beta/basiclib then * '/users/beta/basiclib/current/file.bet' -> convertFilePath -> ... * and * '~cn/beta/basiclib/file.bet' -> convertFilePath -> ... * * will give the same result, and the result will be the exit-parameter of * the first executed call of "convertFilePath". * Notice that if the file itself is a link to another file, these two * disk entries are considered different. * Notice also that in this special pathhandler, it is significant whether * the path are terminated by '/' or not: If it is, the path is considered * a directory. *) <<SLOT FileNameConverterLib: attributes>>; convertFilePath::< (# fileNotFound:< (# do INNER #); convert: @... do convert #); init::< (# ... #); FCPrivate: @... #)
| 14.8 Pathhandler Interface | © 1994-2002 Mjølner Informatics |
[Modified: Friday August 10th 2001 at 14:42]
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