Redirecting dbv output to a file

this is a short note for everyone, who is still wondering why a simple shell construct like a redirect operator to a file won’t work for dbv (dbverify).

imagine a situation where you’re about to dbv-scan a good couple of datafiles and want to concatenate the output into a summary file. one approach is, probably, to just redirect/concatenate the output of dbv using >, create or cleanup the file, and >>, append the file, like so (please do not kick me for the weird “>” formatting below, the view plain link will show it correctly):

dbv file=c:\data01.dbf > dbv.log
dbv file=c:\data02.dbf >> dbv.log

however, the resulting file will be empty. the reason is, that for whatever sake, dbv does not write write to channel stdout, as one might expect, but to channel stderr (???). a simple trick to circumvent this issue is to overlay stdout and stderr by writing:

dbv file=c:\data01.dbf > dbv.log 2>&1
dbv file=c:\data02.dbf >> dbv.log 2>&1

here, the channel stdout is denoted by 1 and stderr by 2, respectively. to have it complete, channel stdin is usually identified by 0, if anyone may need to know it.

the same is, by the way, true for loadjava.