On Fri, 13 Dec 2002, Ashley M. Kirchner wrote: > > Theoretically, in my head, this ought to function, however I wanted > to run it past by some of the shell guru's on here, see if anyone spots > any logistical problems with this. I'm trying to run a particular > command several time (it's a backup script, using cp/rsync). First, the > script renames the old hierarchy of directories then performs the actual > backup. So, you're looking at something like this: > > if [ -d $SNAPSHOT/daily.5 ] ; then \ > $MV $SNAPSHOT/daily.5 $SNAPSHOT/daily.6 ; \ > fi;
first, you should delete the .6 directory, otherwise the .5 directory will be copied as *subdirectory* of .6. > if [ -d $SNAPSHOT/daily.4 ] ; then \ > $MV $SNAPSHOT/daily.4 $SNAPSHOT/daily.5 ; \ > fi; > if [ -d $SNAPSHOT/daily.3 ] ; then \ > $MV $SNAPSHOT/daily.3 $SNAPSHOT/daily.4 ; \ > fi; > if [ -d $SNAPSHOT/daily.2 ] ; then \ > $MV $SNAPSHOT/daily.2 $SNAPSHOT/daily.3 ; \ > fi; > if [ -d $SNAPSHOT/daily.1 ] ; then \ > $MV $SNAPSHOT/daily.1 $SNAPSHOT/daily.2 ; \ > fi; > > > My question is, can I shorten this with a FOR loop: > > for idx in 5 4 3 2 1 ; do \ > if [ -d $SNAPSHOT/daily.$idx ] ; then \ > $MV $SNAPSHOT/daily.$idx $SNAPSHOT/daily.`expr $idx + 1` ; \ > fi; > done sure, but why use expr? why not just use the arithmetic built into bash, as in $SNAPSHOT/daily.$((idx+1)) ?? rday -- redhat-list mailing list unsubscribe mailto:[EMAIL PROTECTED]?subject=unsubscribe https://listman.redhat.com/mailman/listinfo/redhat-list
