-- © Copyright 1999, John Halleck, All rights resurved. -- Give a Base 64 hash value for a Text file. -- Text files have the problem that end of line varies from machine to -- machine. Therefore most hash's of text files require canonicalization -- of end of line to the "network standard" of carriage return followed -- by Line Feed. -- This is part of a project documented at http://www.cc.utah.edu/~nahaj/ with Ada.Text_IO; use Ada.Text_IO; with Ada.Command_Line; use Ada.Command_Line; with SHA; use SHA; with SHA.Strings; use SHA.Strings; with SHA.Process_Data; use SHA.Process_Data; pragma Elaborate_All (SHA.Process_Data); procedure SHA_B64_File is Given : File_Type; Result : B64_SHA_String; Input : Character; begin if Argument_Count = 0 then Put_Line ("??? file names must be provided as arguments"); Set_Exit_Status (Failure); return; end if; for I in 1 .. Argument_Count loop begin -- Unfortunately, Ada does not have "raw" file IO defined for -- files, so the kludge below is used to read each 8 bit -- character from the file. -- Stream IO comes close... -- On machines like the Sperry Univac 1100 series machines -- bytes are four nine-bit bytes per word, and this doesn't -- work at all. Since the SHA hash is defined based on bits -- (and only by extension for bytes) any file on any machine should -- be hashable. The limitations of the standard IO package in Ada -- don't allow a machine indepentdent way of doing this. -- SO... the hack below works on PC's, Macintoshes, and Unix boxes, -- (Where a file may be completely read as 8 bit bytes.) But it -- is far from being portable. Open (Given, In_file, Argument (I)); Initialize; loop begin Get_Immediate (Given, Input); Add (Byte (Character'Pos (Input))); exception when End_Error => exit; end; end loop; Close (Given); Result := B64_From_SHA (Finalize); Put_Line (String (Result)); exception when Name_Error => Put (Standard_Error, "File """); Put (Standard_Error, Argument (I)); Put_Line (Standard_Error, """ was a bad name."); Set_Exit_Status (Failure); when Status_Error => Put (Standard_Error, Argument (I)); Put_Line (Standard_Error, " Doesn't seem to exist."); Set_Exit_Status (Failure); end; end loop; end SHA_B64_File;
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© Copyright 2000 by John Halleck, All Rights Reserved.
This snapshot was last modified on August 31st, 2000
And the underlying file was last modified on August 24th, 2000