On Fri, 2010-06-25 at 12:33 -0700, JD wrote: > > On 06/25/2010 12:04 PM, Bill Crawford was caught red-handed while writing:: > > On 25 June 2010 19:38, JD<jd1...@gmail.com> wrote: > > > >> cd /var/lib > >> sudo tar cjf - rpm> rpm.tar.bz2 > >> sh: rpm.tar.bz2: cannot create [Permission denied] > sudo only runs the "tar" command; the redirect (>) is > > done by the shell, and since you aren't root, you can't write in > > /var/lib.
The classic example to illustrate this is: $ cat a b > a This is supposed to append b to a, but what actually happens is that the redirection truncates a first, and you wind up with a copy of b in a and the original contents of a are lost (do not ask how I learned this; the answer is "the hard way" )-: $ cat b >> a is the right way to do that. In both of these cases, the problem is that the shell does the redirection first before executing the commands. --Greg -- users mailing list users@lists.fedoraproject.org To unsubscribe or change subscription options: https://admin.fedoraproject.org/mailman/listinfo/users Guidelines: http://fedoraproject.org/wiki/Mailing_list_guidelines
