EDT (Univac)
EDT is a
The Univac/Fujitsu EDT editor is a line-based editor, in that it does not use function keys. Unlike editors such as
Commands are sent to the editor by typing in text in the same manner as entering regular text, but the first character of the line (other than a space) is the command symbol, which defaults to the at sign ("
If line numbers are not present in the original file, the editor supplies a pseudo-line number for use in editing each line. Because of the
Commands in EDT generally consist of a command (which is case insensitive), which may be followed by a range of line numbers that the command was to act upon, and a subfunction indicating how the command is to act. The range was either expressed as a single line number, a range of lines separated by a dash, (e.g. 5-8 would mean any line numbered 5.0000 through 8.9999 inclusive), or a group of lines, each separated by a comma. Some symbols are available to represent various values, such as the ampersand "&" or the word "all" representing every line in the file.
For example, to alter every "To" in a document to the word "From" you would type in
@ON ALL CHANGE "To" TO "From"
or
@on & change "To" to "From"
followed by the transmit key (equivalent to Enter on a PC), and the editor would perform the action. Editing was basically full-screen, with actions not taking place until the user pressed the transmit key, a procedure very similar to today's practice of entering text into an input box in a web page, with no action being taken until the user clicks on the
Univac/Fujitsu's EDT editor provides extremely powerful editing capabilities, including
- text formatting similar to Runoff(in which commands were given for text editing by preceding lines with a period)
- possibly one of the first programs (the Univac 90/60 goes back to the late 1960s and early 1970s) to support the use of plugins to allow other programs to use the text the editor held in memory, as well as send commands back to the editor for processing.
- sort
- search
- editing of plain text and files with line numbers
- direct on-disk editing of files too large to hold in memory
Fujitsu's current release of EDT also supports Unicode, which did not exist when Univac released its version of EDT.
References
- Unisys Corporation, 1975
- ^ Current (V17) PDF manuals for Fujitsu EDT editor (Retrieved 2013-08-08)