New -osirrox option auto_chmod_on

libisoburn/trunk/xorriso/xorriso.1

@@ -2,7 +2,7 @@
 .\" First parameter, NAME, should be all caps
 .\" Second parameter, SECTION, should be 1-8, maybe w/ subsection
 .\" other parameters are allowed: see man(7), man(1)
-.TH XORRISO 1 "Jun, 14, 2008"
+.TH XORRISO 1 "Jun, 20, 2008"
 .\" Please adjust this date whenever revising the manpage.
 .\"
 .\" Some roff macros, for reference:
@@ -1627,7 +1627,7 @@ If disk file objects already exist then the settings of -overwrite and
 of -overwrite "nondir". I.e. directories cannot be deleted.
 .br
 Access permissions of files in the ISO image do not restrict restoring.
-The permissions on disk have to allow writing, of course.
+The directory permissions on disk have to allow rwx.
 .TP
 \fB\-osirrox\fR "on"|"device_files"|"off"[:option:...]
 Setting "off" disables disk filesystem manipulations. This is the default
@@ -1647,10 +1647,13 @@ restored.
 .br
 Option "concat_split_on" is default. It enables restoring of split file
 directories as data files if the directory contains a complete collection
-of -cut_out part files.
-.br
-With option "concat_split_off" such directories are
+of -cut_out part files. With option "concat_split_off" such directories are
 handled like any other ISO image directory.
+.br
+Option "auto_chmod_off" is default. If "auto_chmod_on" is set then access
+restrictions for disk directories get circumvented if those directories
+are owned by the effective user who runs xorriso. This happens by temporarily
+granting rwx permission to the owner. It will not work with ACL restrictions.
 .TP
 \fB\-extract\fR iso_rr_path disk_path
 Restore the file objects at and underneath iso_rr_path to their corresponding
@@ -1927,6 +1930,8 @@ Adjust thresholds for verbosity, exit value and program abort
 Examples of input timestrings
 .br
 Incremental backup of a few directory trees
+.br
+Restore directory trees from a particular ISO session to disk
 .SS
 .B As superuser learn about available drives
 Consider to give rw permissions to those users or groups
@@ -2152,25 +2157,12 @@ on media and if the expected changes are much smaller than the full backup.
 An update run will probably save no time but last longer than a full backup.
 Another good reason may be given if read speed is much higher than write speed.
 .br 
-.br
 With \fBmount\fR option \fB"sbsector="\fR it is possible to access the session
 trees which represent the older backup versions. With CD media, Linux mount
 accepts session numbers directly by its option "session=".
 .br
 Multi-session media and most overwriteable media written by xorriso can tell
 the sbsector of a session by xorriso option -toc.
-Another way to keep track of incremental sessions is to
-set before writing a suitable path for xorriso option -session_log where
-the sbsector number gets recorded as the second word in each line.
-.br
-Independently of mount there is xorriso option \fB-osirrox on\fR which enables
-the builtin restore commands -extract, -cpx and others. They operate on the
-session eventually selected by option \fB-load\fR.
-.br
-\fBDo not write more than about 50 sessions\fR to one multi-session media.
-Theoretical limits are higher but in practice the media deteriorate more early.
-It might also be that your operating system has a session limit with mount.
-An overview of sessions is given by option -toc.
 .br
 Sessions on multi-session media are separated by several MB of unused blocks.
 So with small sessions the payload capacity can become substantially lower
@@ -2184,15 +2176,32 @@ get endangered by the new write operation, while the newest backup is
 stored safely on a different media.
 Always have a blank media ready to perform a full backup in case the update
 attempt fails due to insufficient remaining capacity.
-.br 
-If you have enough re-useable media for a round-robin scheme then better do
-full backups with blank media each time. Blanking can be achieved by
-either a separate run:
+.SS
+.B Restore directory trees from a particular ISO session to disk
+This is an alternative to mounting the media and using normal file operations.
 .br
-\fB$\fR xorriso -outdev /dev/sr0 -blank as_needed -eject all
+First check which backup sessions are on the media:
 .br
-or in the update run by using option -blank "as_needed" before
-option -update_r.
+\fB$\fR xorriso -outdev /dev/sr0 -toc
+.br
+Then load the desired session and copy the file trees to disk.
+Avoid to eventually create /home/thomas/restored without rwx-permission.
+.br
+\fB$\fR xorriso -load volid PROJECTS_MAIL_2008_06_19_205956 \\
+.br
+ -indev /dev/sr0 \\
+.br
+ -osirrox on:auto_chmod_on \\
+.br
+ -chmod u+rwx / \\
+.br
+ -extract /open_source_projects \\
+.br
+          /home/thomas/restored/open_source_projects \\
+.br
+ -extract /personal_mail /home/thomas/restored/personal_mail
+.br
+ -rollback_end
 .br
 .SH FILES
 .SS