fusefile \- FUSE file mount for combining file fragments
.SH SYNOPSIS
-.B fusefile \fR[fuse options\fR] \fBmountpoint\fR \fIfilename/from-to\fR ...
+.B fusefile \fR[\fIfuse-opts\fR] \fBmountpoint\fR \fR[\fIoverlay\fR] \fIfilename/from-to\fR ...
.SH DESCRIPTION
file which gets distributed accordingly to the fragments, but cannot
change size.
+An optional overlay file is declared with the "-overlay:filename"
+argument between the mount point and the fragments. This file is then
+set up as an overlay for capturing writes to the fused file. The
+overlay file will contain the written fused file regions, followed by
+meta data to distinguish between written content and "holes" (where
+content comes from the fused fragments).
+
The fragment arguments include the filename of a source file, and
optionally start and end byte positions. All in all there five
variations:
\fB$ fusefile y x/2442: x/:2442\fR
.RE
+Protect raw disk image file with an overlay:
+.RS
+\fB# fusefile -ononempty disk.raw -overlay:today disk.raw
+.RE
+By this set up, the overlay file, "today", will protect the disk image
+file, "disk.raw" from changes, and also override the pathname
+"disk.raw" to be the fused file.
+
.SH NOTES
Note that \fBfusefile\fR opens the nominated source file or files
If the mountpoint file doesn't exist, then \fBfusefile\fR creates it,
and removes it when unmounted.
+Using an overlay file makes the fused file writable regardless of the
+fused fragemnts with the overlay file containing any changes to the
+original. The overlay file is reusable for subsequent fusing of the
+same fragments for reconstructing a prior session.
.SH AUTHOR