=========================================== MAGnet MAnifest (.magma) Simple List Format by Arne Babenhauserheide ( arne_bab@web.de - http://draketo.de ) MAGMA files are a way to transport Magnet-lists and additional information in a human-readable way. (1) Magma files are a line-oriented text format consisting of a header line followed by any number of comments and topics. It is based off YAML and will likely be extended in the future to be able to contain more information. This is the first draft and specifies how a simple parser can extract Magnets from a Magma-File. (2) Any line in which the first non-whitespace character is '#' is a comment through to the end of the line. When a '#' appears somewhere in a line, that line is a comment from the '#' through to the end of the line. For example: # this is a comment (3) Lines consisting solely of whitespace are ignored. (4) A line which begins with "list:" starts a list of topics, which continues, till another line starts with any character but a whitespace. A line starting with a "#" may be ignored for this purpose (We don't want a thoughtlessly placed comment to break the list too early). (5) Any line in that list beginning with " - " (space-hyphen-space) is considered the start of a topic. (6) A topic continues till any line begins with less than two spaces followed by any other character. A new topic begins as described in (5). (7) If the topic begins with a magnet-link, that magnet-link must be sourrounded by double-quotes. Inside these double-quotes any whitespace is ignored. Also any linebreak which is followed by at least three spaces is ignored. (8) A topic may contain any URI and any number of additional objects. Programs should ignore every line beginning with an object-nominator they don't understand. Any line beginning with two spaces and any character but a "-" or a "#" is considered the beginning of an object. More on objects in (10). Any line beginning with two spaces and a "#" is a comment inside the topic. If the topic contains a magnet URI, the various magnet attributes have their usual meanings. Note that this means the following two lines have an identical meaning inside a magma file -- each specifies a single exact topic: - urn:sha1:BLAH - "magnet:?xt=urn:sha1:BLAH" (9) Any line inside the double quotation beginning with three or more whitespaces, where the first non-whitespace character is not a '#', is considered a continuation of the previous topic line and should be appended with no intervening whitespace. For example: - "magnet:?xt=urn:sha1:BLAH &dn=magnacarta.jpg" ...is equivalent to... - "magnet:?xt=urn:sha1:BLAH&dn=magnacarta.jpg" (10) Additinal file information can be given as objects in the format "nominator:information", where the nominator must be preceded by two spaces and must be in a new line. Any whitespaces directly following the colon can be ignored (as they will most probable be placed for greater readability). For example this would be a topic which named the hash, download name and an alternate location without the use of a magnet-link. Watch the second line being indented by two spaces, one more than the "-": - urn:sha1:BLAH dn:magnacarta.jpg as:http://BLAK This should be expanded into the following magnet-link to pass it on to magnet- aware programs: magnet:?xt=urn:sha1:BLAH&dn=magnacarta.jpg&as=http://BLAK (11) The first line should begin "#MAGMA" and a Version number. In this case "#MAGMAv0.2". This can be ignored by simpleminded parsers as a comment, but is also a hint/"magic number" to help indicate the file's type in situations where the manifest may have been acquired solely by a typeless urn:sha1: (etc.) identifier. The rest of the first line must not be used as a regular comment. (See #12.) (12) The first line may include an optional "virtual magnet URI" describing the manifest itself. In such a magnet URI, the 'mt' may be set to '.' to mean 'this'. For example: #MAGMAv0.2 magnet:?mt=.&dn=My%20First%20Manifest This first line cannot make use of the continuation facility described in (5). (13) Another, more extensible Magnet Manifest format will be defined in the future. The specs for this Version of the Magnet Manifest (0.2) will stay compatible at least till v0.4 and also after that magnnets should be extractable from MAGMA-files using the sheme described in here. ==================================== AN EXAMPLE You might come across a magnet URI like either of the following: magnet:?xt=urn:sha1:B4LGBGBX2J7PBNXRCQVS474Y5DW3I6WB &dn=gnufu-files-v0.2.magma &xs=http://edrikor.dyndns.org:9845/uri-res/N2R?urn:sha1: B4LGBGBX2J7PBNXRCQVS474Y5DW3I6WB &as=http://magnet-uri.sourceforge.net/proposals/arne/gnufu-files.magma magnet:?mt=http://magnet-uri.sourceforge.net/proposals/arne/gnufu-files.magma By either finding a file with the exact matching SHA1 (in the first case), or by fetching the given HTTP URL (in the second case), you might wind up with the following file: ==== BEGIN EXAMPLE FILE ==== #MAGMAv0.2 magnet:?mt=.&dn=gnufu-files-v0.2.magma&as=http://magnet-uri.sourceforge.net/proposals/arne/gnufu-files-v0.2.magma # these are the documents created for GnuFU: Gnutella For Users, # a simple guide to Gnutella and recent changes in the Gnutella-network # written in userfriendly style. list: - "magnet:?xt=urn:sha1:7BHEGP445NVQUNSDFHOK5FFC3P65HANG &dn=gnufu-en-2004-06-26.rtd.zip &xs=http://edrikor.dyndns.org:9845 /uri-res/N2R?urn:sha1:7BHEGP445NVQUNSDFHOK5FFC3P65HANG" - "magnet:?xt=urn:sha1:GK6T2LZV2IPAY57XWQTCQLWWGEGPJ6SG &dn=gnufu-en-2004-06-26.pdf &xs=http://edrikor.dyndns.org:9845 /uri-res/N2R?urn:sha1:GK6T2LZV2IPAY57XWQTCQLWWGEGPJ6SG" - "magnet:?xt=urn:sha1:3QL5VEGHQZWNP34NCLZVSIZF3HK4P5VZ &dn=gnufu-de-2004-06-26.rtd.zip &xs=http://edrikor.dyndns.org:9845 /uri-res/N2R?urn:sha1:3QL5VEGHQZWNP34NCLZVSIZF3HK4P5VZ" - "magnet:?xt=urn:sha1:2A5ERFKC3EBAUTRQSIYZY5GABB6MYMXF &dn=gnufu-de-2004-06-26.pdf &xs=http://edrikor.dyndns.org:9845 /uri-res/N2R?urn:sha1:2A5ERFKC3EBAUTRQSIYZY5GABB6MYMXF" ==== END EXAMPLE FILE ==== Comments? Suggestions? Problems?