To use gtbl, two special commands are used to indicate to groff that the area between the two commands is to be processed as gtbl instructions. Tables are independent of each other with gtbl, meaning that each must contain all the information for formatting the data within the table and can't rely on a previous format. Let's look at the important parts of the gtbl layout first, and then see how they are combined to produce finished tables. Executing gtbl Because gtbl is a preprocessor, it is invoked on the source file, and then the results are passed to groff. If you are processing more than one file at a time, or you need to send the output of gtbl to another preprocessor, such as geqn, you use piping slightly differently.
Options There can be a single line of options after a .TS command that affects the entire table.
Any options must follow the .TS command. If more than one option is specified, they must be separated by spaces, commas, or tabs, and terminate in a semicolon. Uses m and n as equation delimiters. When gtbl tries to lay out a table, it tries to keep the entire table on one page if possible, even if it has to eject the previous page only partially completed. This can sometimes cause problems because gtbl can make mistakes estimating the size of the table prior to generating it, especially if there are embedded line commands that affect spacing or point size.