New option -grow_blindly

libisoburn/trunk/xorriso/xorriso.1

@@ -72,7 +72,7 @@ Session model
 .br
 Media types and states
 .br
-Creating, Growing, Modifying
+Creating, Growing, Modifying, Blind Growing
 .br
 Libburn drives
 .br
@@ -121,7 +121,8 @@ filesystems. This expansion method is referred as emulated growing.
 .PP
 xorriso provides both ways of growing as well as an own method named
 \fBmodifying\fR which produces a completely new ISO image from the old
-one and the modifications. See paragraph Creating, Growing, Modifying below.
+one and the modifications.
+See paragraph Creating, Growing, Modifying, Blind Growing below.
 .PP
 xorriso adopts the concept of multi-session by loading an eventual image
 directory tree, allowing to manipulate it by several actions, and to write
@@ -196,7 +197,7 @@ contain unrecognizable data in the first 32 data blocks.
 media. Often only the first and the last session are visible. Sometimes
 not even that. Option -rom_toc_scan might or might not help in such cases.
 .SS
-.B Creating, Growing, Modifying:
+.B Creating, Growing, Modifying, Blind Growing:
 .br
 A new empty ISO image gets \fBcreated\fR
 if there is no input drive with a valid
@@ -229,11 +230,25 @@ named pipes, character devices, sockets.
 On the other hand modified sessions cannot be written to appendable media
 but to blank media only.
 .br
-Modifying takes place whenever input drive and output drive are not the same.
-This is achieved by options -indev and -outdev.
-.br
 So for this method one needs either two optical drives or has to work with
 filesystem objects as source and/or target media.
+.br
+Modifying takes place if input drive and output drive are not the same and
+if option -grow_blindly is set to its default "off".
+This is achieved by options -indev and -outdev.
+.PP
+If option -grow_blindly is set to a non-negative number and if -indev and
+-outdev are both set to different drives, then \fBblind growing\fR is
+performed. It produces an add-on session which is ready for being written
+to the given block address. This is the usage model of
+.br
+ mkisofs -M $indev -C $msc1,$msc2 -o $outdev
+.br
+which gives much room for wrong parameter combinations and should thus only be
+employed if a strict distinction between ISO formatter xorriso and the burn
+program is desired. -C $msc1,$msc2 is equivalent to:
+.br
+ -load sbsector $msc1 -grow_blindly $msc2
 .SS
 .B Libburn drives:
 .br
@@ -245,8 +260,8 @@ Rock Ridge info must be present in existing ISO images and it will be generated
 by the program unconditionally.
 .PP
 Output drive, i.e. target for writing, can be any libburn drive.
-Some drive types do not support the method of growing but only the method
-of modifying. They all are suitable for newly created images.
+Some drive types do not support the method of growing but only the methods
+of modifying and blind growing. They all are suitable for newly created images.
 .br
 All drive file objects have to offer rw-permission to the user of xorriso.
 Even those which will not be useable for reading an ISO image.
@@ -277,7 +292,8 @@ their path in the filesystem. E.g.:
 If path leads to a regular file or to a block device then the emulated drive
 is random access readable and can be used for the method of growing if it
 already contains a valid ISO 9660 image. Any other file type is not readable
-via "stdio:" and can only be used as target for the method of modifying.
+via "stdio:" and can only be used as target for the method of modifying or
+blind growing.
 Non existing paths in existing directories are handled as empty regular files.
 .PP
 A very special kind of pseudo drive are open file descriptors. They are
@@ -427,13 +443,15 @@ without aquiring a new one.
 .TP
 \fB\-indev\fR address
 Set input drive and load an eventual ISO image. If the new input drive differs
-from -outdev then switch from growing to modifying. The same rules and
-restrictions apply as with -dev.
+from -outdev then switch from growing to modifying or to blind growing.
+It depends on the setting of -grow_blindly which of both gets activated.
+The same rules and restrictions apply as with -dev.
 .TP
 \fB\-outdev\fR address
 Set output drive and if it differs from the input drive then switch from
-growing to modifying. Unlike -dev and -indev this action does not load a
-new ISO image. So it can be performed even if there are pending changes.
+growing to modifying or to blind growing. Unlike -dev and -indev this action
+does not load a new ISO image. So it can be performed even if there are pending
+changes.
 .br
 -outdev can be performed without previous -dev or -indev. In that case an
 empty ISO image with no changes pending is created. It can either be populated
@@ -446,6 +464,17 @@ apply. See above paragraph "Libburn drives".
 An empty address string "" gives up the current output drive
 without aquiring a new one. No writing is possible without an output drive.
 .TP
+\fB\-grow_blindly\fR "off"|predicted_nwa
+If predicted_nwa is a non-negative number then perform blind growing rather
+than modifying if -indev and -outdev are set to different drives.
+"off" or "-1" switch to modifying, which is the default.
+.br
+predicted_nwa is the block address where the add-on session of blind
+growing will finally end up. It is the responsibility of the user to ensure
+this final position and the presence of the older sessions. Else the
+overall ISO image will not be mountable or will produce read errors when
+accessing file content.
+.TP
 \fB\-load\fR entity id
 Load a particular (possibly outdated) ISO image from a -dev or -indev which
 hosts more than one session. Usually all available sessions are shown with
@@ -908,8 +937,8 @@ Discard the manipulated ISO image. End program without loading a new image.
 \fB\-commit\fR
 Perform the write operation. Afterwards eventually make the
 -outdev the new -dev and load the image from there.
-Switch from eventual modifiying mode to growing mode.
-(A subsequent -outdev will activate modification mode.)
+Switch to growing mode.
+(A subsequent -outdev will activate modification mode or blind growing.)
 -commit is performed automatically at end of program if there
 are uncommitted manipulations pending.
 So, to perform a final write operation with no new -dev