On UNIX and MS-DOS systems, jed creates backup files by appending
a ~ character to the filename. The VMS operating system
handles backup files itself. jed periodically auto-saves its
buffers. On UNIX and MS-DOS, auto-save files are prefixed with the
pound sign #. On VMS, they are prefixed with _$. The auto-save interval may be changed by setting the variable
MAX_HITS to the desired value. The default is 300 “hits” on
the buffer. A “hit” is defined as a key which MAY change the state
of the buffer. Cursor movement keys do not cause hits on the buffer.
Like many of jed’s features, the names of auto-save and backup files can be
controlled by the user. The file site.sl defines two functions,
make_backup_filename, and make_autosave_filename that
generate the file names described in the previous paragraph. Like all
S–Lang functions, these functions may be overloaded and replaced with
different ones. See also information about find_file_hook in the
section on hooks.
On UNIX systems, jed catches most signals and tries to auto-save its buffers in the event of a crash or if the user accidently disconnects from the system (SIGHUP).
If an auto-save file exists and you is desire to recover data from the
auto-save file, use the function recover_file. Whenever jed finds a
file, it checks to see if an auto-save file exists as well as the file’s
date. If the dates are such that the auto-save file is more recent jed
will display a message in the mini-buffer alerting the user of this fact
and that the function recover_file should be considered.