Format of Version 5 Babyl Files: Warning: This was written Tuesday, 12 April 1983 (by Eugene Ciccarelli), based on looking at a particular Babyl file and recalling various issues. Therefore it is not guaranteed to be complete, but it is a start, and I will try to point the reader to various Babyl functions that will serve to clarify certain format questions. Also note that this file will not contain control-characters, but instead have two-character sequences starting with Uparrow. Unless otherwise stated, an Uparrow <character> is to be read as Control-<character>, e.g. ^L is a Control-L. Versions: First, note that each Babyl file contains in its BABYL OPTIONS section the version for the Babyl file format. In principle, the format can be changed in any way as long as we increment the format version number; then programs can support both old and new formats. In practice, version 5 is the only format version used, and the previous versions have been obsolete for so long that Emacs does not support them. Overall Babyl File Structure: A Babyl file consists of a BABYL OPTIONS section followed by 0 or more message sections. The BABYL OPTIONS section starts with the line "BABYL OPTIONS:". Message sections start with Control-Underscore Control-L Newline. Each section ends with a Control-Underscore. (That is also the first character of the starter for the next section, if any.) Thus, a three message Babyl file looks like: BABYL OPTIONS: ...the stuff within the Babyl Options section... ^_^L ...the stuff within the 1st message section... ^_^L ...the stuff within the 2nd message section... ^_^L ...the stuff within the last message section... ^_ Babyl is tolerant about some whitespace at the end of the file -- the file may end with the final ^_ or it may have some whitespace, e.g. a newline, after it. The BABYL OPTIONS Section: Each Babyl option is specified on one line (thus restricting string values these options can currently have). Values are either numbers or strings. The format is name, colon, and the value, with whitespace after the colon ignored, e.g.: Mail: ~/special-inbox Unrecognized options are ignored. Here are those options and the kind of values currently expected: MAIL Filename, the input mail file for this Babyl file. You may also use several file names separated by commas. Version Number. This should always be 5. Labels String, list of labels, separated by commas. Message Sections: A message section contains one message and information associated with it. The first line is the "status line", which contains a bit (0 or 1 character) saying whether the message has been reformed yet, and a list of the labels attached to this message. Certain labels, called basic labels, are built into Babyl in a fundamental way, and are separated in the status line for convenience of operation. For example, consider the status line: 1, answered,, zval, bug, The 1 means this message has been reformed. This message is labeled "answered", "zval", and "bug". The first, "answered", is a basic label, and the other two are user labels. The basic labels come before the double-comma in the line. Each label is preceded by ", " and followed by ",". (The last basic label is in fact followed by ",,".) If this message had no labels at all, it would look like: 1,, Or, if it had two basic labels, "answered" and "deleted", it would look like: 1, answered, deleted,, zval, bug, The & Label Babyl Message knows which are the basic labels. Currently they are: deleted, unseen, recent, and answered. After the status line comes the original header if any. Following that is the EOOH line, which contains exactly the characters "*** EOOH ***" (which stands for "end of original header"). Note that the original header, if a network format header, includes the trailing newline. And finally, following the EOOH line is the visible message, header and text. For example, here is a complete message section, starting with the message starter, and ending with the terminator: ^_^L 1,, wordab, eccmacs, Date: 11 May 1982 21:40-EDT From: Eugene C. Ciccarelli <ECC at MIT-AI> Subject: notes To: ECC at MIT-AI *** EOOH *** Date: Tuesday, 11 May 1982 21:40-EDT From: Eugene C. Ciccarelli <ECC> To: ECC Re: notes Remember to pickup check at cashier's office, and deposit it soon. Pay rent. ^_ ;;; Babyl File BNF: ;;; Overall Babyl file structure: Babyl-File ::= Babyl-Options-Section (Message-Section)* ;;; Babyl Options section: Babyl-Options-Section ::= "BABYL OPTIONS:" newline (Babyl-Option)* Terminator Babyl-Option ::= Option-Name ":" Horiz-Whitespace BOptValue newline BOptValue ::= Number | 1-Line-String ;;; Message section: Message-Section ::= Message-Starter Status-Line Orig-Header EOOH-Line Message Terminator Message-Starter ::= "^L" newline Status-Line ::= Bit-Char "," (Basic-Label)* "," (User-Label)* newline Basic-Label ::= Space BLabel-Name "," User-Label ::= Space ULabel-Name "," EOOH-Line ::= "*** EOOH ***" newline Message ::= Visible-Header Message-Text ;;; Utilities: Terminator ::= "^_" Horiz-Whitespace ::= (Space | Tab)* Bit-Char ::= "0" | "1"