New option -update (not yet completed)

libisoburn/trunk/xorriso/xorriso.1

@@ -542,6 +542,20 @@ as files to add, if they are not parameters to appropriate commands.
 Like -add but read the parameter words from file disk_path.
 One pathspec resp. disk_path pattern per line. 
 .TP
+\fB\-update\fR disk_path iso_rr_path
+Compare file object disk_path with file object iso_rr_path. If they do not
+match, then perform the necessary image manipulations to make iso_rr_path
+a matching copy of disk_path. This comparison can imply lengthy content
+reading before a decision is made. On the other hand it strives for the
+smallest possible amount of add-on data in order to achieve the matching copy.
+.br
+-update is also a convenient compromise between -add addressing and -cp_r
+addressing: Its semantics is similar to -add and thus avoids the pitfalls
+inherited from cp -r behavior. Its syntax resembles cp, though.
+.br
+Note: Not all subtleties of link following are implemented yet.
+Use with caution.
+.TP
 \fB\-cpr\fR disk_path [***] iso_rr_path
 Insert the given files or directory trees from filesystem 
 into the ISO image.
@@ -1253,7 +1267,7 @@ Similar to shell command du -sk.
 Like -find but operating on local filesystem and not on the ISO image.
 This is subject to the settings of -follow.
 .br
--findx accepts the -exec actions as does -find. But it will except two
+-findx accepts the -exec actions as does -find. But except two
 other actions it will allways perform action "echo".
 .br
 "in_iso" iso_rr_path_start reports the path if its counterpart exist in
@@ -1263,7 +1277,8 @@ by iso_rr_path_start.  E.g.:
   -find /home -exec in_iso /
 .br
 "not_in_iso" iso_rr_path_start reports the path if its counterpart does
-not exist in the ISO image. The format is the same as with command -compare.
+not exist in the ISO image. The report format is the same as with command
+-compare.
 E.g.
 .br
   -find /home -exec not_in_iso /