SiSU has plaintext and binary filetypes, and can process either type of document.
SiSU documents are prepared as plain-text (utf-8) files with SiSU markup. They may make reference to and contain images (for example), which are stored in the directory beneath them _sisu/image. SiSU plaintext markup files are of three types that may be distinguished by the file extension used: regular text .sst; master documents, composite documents that incorporate other text, which can be any regular text or text insert; and inserts the contents of which are like regular text except these are marked .ssi and are not processed.
SiSU processing can be done directly against a sisu documents; which may be located locally or on a remote server for which a url is provided.
SiSU source markup can be shared with the command:
sisu -s [filename]
The most common form of document in SiSU, see the section on SiSU markup.
Composite documents which incorporate other SiSU documents which may be either regular SiSU text .sst which may be generated independently, or inserts prepared solely for the purpose of being incorporated into one or more master documents.
The mechanism by which master files incorporate other documents is described as one of the headings under under SiSU markup in the SiSU manual.
Note: Master documents may be prepared in a similar way to regular documents, and processing will occur normally if a .sst file is renamed .ssm without requiring any other documents; the .ssm marker flags that the document may contain other documents.
Note: a secondary file of the composite document is built prior to processing with the same prefix and the suffix ._sst 17
Inserts are documents prepared solely for the purpose of being incorporated into one or more master documents. They resemble regular SiSU text files except they are ignored by the SiSU processor. Making a file a .ssi file is a quick and convenient way of flagging that it is not intended that the file should be processed on its own.
A sisupod is a zipped SiSU text file or set of SiSU text files and any associated images that they contain (this will be extended to include sound and multimedia-files)
SiSU plaintext files rely on a recognised directory structure to find contents such as images associated with documents, but all images for example for all documents contained in a directory are located in the sub-directory _sisu/image. Without the ability to create a sisupod it can be inconvenient to manually identify all other files associated with a document. A sisupod automatically bundles all associated files with the document that is turned into a pod.
The structure of the sisupod is such that it may for example contain a single document and its associated images; a master document and its associated documents and anything else; or the zipped contents of a whole directory of prepared SiSU documents.
The command to create a sisupod is:
sisu -S [filename]
Alternatively, make a pod of the contents of a whole directory:
SiSU processing can be done directly against a sisupod; which may be located locally or on a remote server for which a url is provided.
17. .ssc (for composite) is under consideration but ._sst makes clear that this is not a regular file to be worked on, and thus less likely that people will have "accidents", working on a .ssc file that is overwritten by subsequent processing. It may be however that when the resulting file is shared .ssc is an appropriate suffix to use.