Content types
Most printers can print files of the same type as the printer type and of the simple type (ASCII files).
The content-type attribute is defined with the -I content-type-list option of the lpadmin command. Most printers can print files of two types: the same type as the printer type (if the printer type is defined) and the type simple (meaning an ASCII file), which is the default content type for all printers.
| Item | Descriptor |
|---|---|
| backspace | Moves the carriage back one space, except at the beginning of a line |
| tab | Moves the carriage to the next tab stop; by default, stops are spaced every 8 columns on most printers |
| linefeed | Moves the carriage to the beginning of the next line (may require special port settings for some printers—see Printer port characteristics) |
| form feed | Moves the carriage to the beginning of the next page |
| carriage return | Moves the carriage to the beginning of the same line (may fail on some printers) |
The word carriage may be archaic for modern laser printers, but these printers perform actions similar to those done by a carriage. If a printer can handle several types of files, including simple, you must include simple explicitly in the content type list. If you do not want a printer to accept files of type simple, specify a blank content-type-list (-I "") on the lpadmin command line. Some printers, though, can accept (and print correctly) several different types of files. When adding this kind of printer, specify the names of the content types that the new printer accepts by adding these names to the list. (By default, the list contains only one type: simple.) If you are adding a remote printer, list the content types that have been established for it by the administrator of the system on which it resides.
The content-type-list is a list of names separated by commas or spaces. If you use spaces to separate the names, enclose the entire list (except for the -I) in quotes.