Lectern: a user interface for viewing documents stored as images Temp-file management

INTERFACE TempFiles;

IMPORT Pathname;

temp file names

PROCEDURE DefaultPrefix(prefix: Pathname.T);
  (* Use the given prefix as default for future temp file names generated by
     calls of Get.  Before the first call of DefaultPrefix,
     a call of Get with defaulted prefix would use a default prefix
     (/tmp on U*ix systems).  The notion of "prefix" is as specified in the
     Pathname interface.  *)

PROCEDURE Get(prefix: TEXT := NIL; part: TEXT := ","; ext: TEXT := NIL): TEXT;
  (* Returns an almost-certainly-unique file name, using prefix provided,
     (or by default the prefix as specified by the Init procedure), and
     a suffix composed of "part" concatenated
     with a manufactured string, and the given extension.  The notions
     of "prefix" and "extension" are as specified for the Pathname.Join
     procedure.  Does not call Note - that's up to you to do.
     For example, on U*x with the default prefix, Get(",x-", "y")
     returns a string of the form "/tmp/,x-*.y" *)

PROCEDURE Note(t: TEXT);
  (* Adds "t" to the list of files to be deleted on program exit.  There
     is no attempt to detect duplicates.  It's probably best to call this
     after creating the file, to avoid spurious warnings about failure to
     delete it (but at the risk of not deleting it, of course). *)

PROCEDURE Forget(t: TEXT);
  (* Removes "t" from the list of files to be delete on program exit.  Fails
     silently if "t" isn't on the list.  It's probably best to call this
     before deleting or renaming the file, to avoid spurious warnings about
     failure to delete it (but at the risk of not deleting it, of course). *)

END TempFiles.