Philippe Troin zei: > severity 297527 wishlist > thanks Hello Philippe,
> Jules Alberts <[EMAIL PROTECTED]> writes: > >> `mt-st status` returns text like this: >> >> ---snippet---------------------------------------- >> SCSI 2 tape drive: >> File number=0, block number=0, partition=0. >> Tape block size 0 bytes. Density code 0x47 (TR-5). >> Soft error count since last status=0 >> General status bits on (41010000): >> BOT ONLINE IM_REP_EN >> ---end snippet------------------------------------ >> >> and the errorlevel is 0 regardless of the actual tape drive >> status. > > I assume you mean "exit status". Of course :) >> If you want a shell script to check the status of the tape, it has >> do do a grep on the output, which is errorprone, especially if the >> author of mt-st would change the returned text in a future >> version. The use of an errorlevel (e.g. 0 if tape is online, 1 if >> offline etc.) would solve this. > > man mt-st says: > > mt exits with a status of 0 if the operation succeeded, 1 > if the operation or device name given was invalid, or 2 if > the operation failed. > > 'mt-st status' performs according to the documentation: it exits > with > an exit status of 0 because it successfully retrieved the tape drive > status information. Therefore it's not an important bug, and I've > downgraded your bug's severity to 'wishlist'. OK. > I do not think that returning a special exit status for the absence > of > the ONLINE flag is a good idea. Tape drives some in different makes > and they do not all report "tape inserted" as "ONLINE" and "tape > ejected" as "! ONLINE". My Sony DDS drive reports ejected as > "! ONLINE && DR_OPEN" and inserted as "ONLINE && ! DR_OPEN". I have > seen some other drives not reporting DR_OPEN. So it's not clear cut > how inserted is defined. The current behavior is at least > consistent. > > As for your application of detecting an open tape drive I'd suggest > sed'ing and grep'ing like this: > > LC_ALL=C mt stat 2> /dev/null \ > | sed -e '1,/^General status bits/d' \ > -e '/^[^[:space:]]/,$d' \ > | grep -q '[[:space:]]ONLINE\([[:space:]]\|$\)' > if [ $? -eq 0 ] > then > echo "Tape inserted" > fi > > (tested to work against mt-st and mt-gnu, BTW) > That should isolate you as much as possible from change in the mt-st > output format. > > Alternately, just open the tape for reading. It will fail unless a > tape is inserted: > > (true < $TAPE ) >& /dev/null && echo "Tape inserted" That's is a good one, elegant and effective. Thanks! > Hope this helps, > Phil. Yes, it does. Thanks again. Groeten, -- Jules Alberts ARBOdienst Limburg BV -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]
