Hi, i wrote: > > xorriso ...the.desired.commands... -rollback_end > > This will perform the commands but then just end the program run > > instead of writing the result
[email protected] wrote: > Thomas, have you tested that? Yes. Just now again. > Sessions 52 and 53, listed below, were created with these commands. > # dest=/dev/sdd > # xorriso -for_backup \ > -dev stdio:"$dest" \ > -assert_volid 'BOB.*' fatal \ > -volid BOB."$(date '+%Y.%m.%d.%H:%M:%S')" \ > -update_r "$source" / \ > -commit \ > -toc \ > -check_md5 failure -- \ > -rollback_end ; > For session 52, no changed files to write. Hence 501s for a > directory. For session 53, several files written. If you don't want actual image production then you must not let xorriso execute command -commit before you give it command -rollback_end . Command -commit performs the image writing and then loads the tree and metadata of the new state of the ISO filesystem. Commands -toc and -check_md5 do not constitute new changes in the loaded model of the next ISO. So the final command -rollback_end makes no difference regardless whether it gets performed or not. Nothing new gets written when the program ends. (Should i stress more often that xorriso commands get executed one by one, unlike mkisofs options which get first interpreted to plan a run and may override previous options before the plan is really executed ?) Try this for a dry run: finalize="-print_size -rollback_end" xorriso -for_backup \ -dev stdio:"$dest" \ -assert_volid 'BOB.*' fatal \ -volid BOB."$(date '+%Y.%m.%d.%H:%M:%S')" \ -update_r "$source" / \ $finalize and the same xorriso run with different finalization commands for a real run with ISO writing: finalize="-commit -toc -check_md5 failure --" xorriso -for_backup \ -dev stdio:"$dest" \ -assert_volid 'BOB.*' fatal \ -volid BOB."$(date '+%Y.%m.%d.%H:%M:%S')" \ -update_r "$source" / \ $finalize Note that in this special case the evaluation of $finalize must not be put in quotation marks. This is because it shall expand to four arguments in the real run. Of course none of these arguments must contain blanks or other whitespace. But in this case they are surely single words. I added command -print_size to the dry run so that xorriso prints on stdout a line like Image size : 30898s before discarding the changes and ending the program. (This combination serves in several of my own backup scripts. So it gets tested from time to time ... but not very often.) Have a nice day :) Thomas
