========
This project implements a "fuse" device to mount as a single file that
-is a concatenation of fragments of one or more files. By default the
-fused file is read-only.
-
-A writeable fused file is set up by associating the mount with a
-"scratch pad file"
+is a concatenation of fragments of one or more files. The fused file
+allows overwriting the parts files, but not changing their sizes, and
+only for parts files that are writable upon first access.
FUSE file mount for combining file fragments.
== SYNOPSIS
- *fusefile* [_fuse options_] *mountpoint* _filename/from-to_ ...
+
+====
+*fusefile* [ _fuse options_ ] *mountpoint* +_filename_/from:to+ ...
+====
## DESCRIPTION
* __filename/-to__ include the file from beginning to the given end position (not included).
- * __filename/from-to__ include the file from the given start position, up to the given end position (not included).
-
- * *pad=*_filename_ when this is given as first argument, the fused
- file is set up as a writable random-access file, where the write
- events are captured appended to the nominated "pad" file. The new
- content is inserted into the fused file but not the original files,
- and fragments are split up and adjusted as needed so as to make the
- write events appear as insertions inteo the fused file.
+ * __filename/from:to__ include the file from the given start position, up to the given end position (not included).
## EXAMPLES
-Insert file "y" into file "x" at position 1200:
+.Insert file "y" into file "x" at position 1200:
- $ fusefile -ononempty x x/-1200 y x/1200
-The bind mount shadows the original file "x", and presents the
-composite instead.
+ $ fusefile -ononempty x x/:1200 y x/1200:
+
+That mount will shadow the original file "x", and presents the
+fused file instead.
+
+.Make file y be a swap of the beginning and end of file "x", at position 2442:
+
+ $ fusefile y x/2442: x/:2442
+
+.Replace a partition in an image file with a different file
-Make file y be a swap of the beginning and end of file "x", at
-position 2442:
+ $ partx -oNR,START,SECTORS disk.raw
+ NR START SECTORS
+ 1 2048 2097152
+ 2 2099200 409600
+ 3 2508800 14268383
+ # Replace partition 2 of 409600 sectors from 2099200 with
+ # the file "insert.fat" clipped to 409600 sectors.
+ $ fusefile -ononempty disk.raw \
+ disk.raw/0:$(( 2099200*512 )) \
+ insert.fat/0:$(( 409600*512 )) \
+ disk.raw/$(( (2099200+409600)*512 )):
- $ fusefile y x/2442 x/-2442
## NOTES
mounting. With the fuse option __-ononempty__ it will bind over an
non-empty file, which may be useful. The source file descriptors
remain open, but the source fragments are not recomputed. If a source
-file changes or reduces in size, anything may happen.
+file changes or reduces in size "behind" the fused file, then anything
+may happen.
-If the mountpoint file doesn't exist, then **fusefile** creates it,
-and removes it when unmounted.
+If the mountpoint file doesn't exist, then **fusefile** creates it and
+removes it when unmounted.
-When a "pad" file is used, it is updated as a simple archive where
-each write event is a new member appended at the end. Each "pad"
-member has a prefix of two newline-terminated text lines telling the
-insertion position and the member size (both as ascii decimal digits),
-before the actual insertion event content.
+Unmounting is done with "fusermount -u __fused file__" as usual.
## AUTHOR