.CD "de \(en disk editor"
.SX "de\fR [\fB\(enw\fR] \fIblock_device"
.SX "de \(enr \fIfile
.FL "\(enr" "Recover a file that has been removed"
.FL "\(enw" "Enable writing, so device can be modified"
.EX "de \(enr /usr/ast/prog.c" "Undo the effects of: \fIrm /usr/ast/prog.c\fR"
.EX "de \(enw /dev/fd0" "Edit \fI/dev/fd0\fR for writing"
.PP
\fIDe\fR is a program for system administrators that allows disks to be
inspected block by block.
A variety of display options and commands are available, as described in
Chap. 9.
For a summary, start the program and type \fIh\fR for help.
The program can also restore files that have just been removed by \fIrm\fR,
provided that the i-node and blocks are still intact.
Another feature is searching disks for ASCII strings, to help locate things
after a crash.
Finally, individual disk words can be changed, for example, the sizes of
block special files.