On Tuesday 26 July 2005 20:03, you wrote: > I don't use backticks, so this'll have the equivalent "$()". > > The command: cat /dev/urandom > is passed to the shell and the shell executes "cat" and sends > the output to the screen without possibility of executing anything > (except the magic stuff recognized by your terminal emulator -- I hope > it can't execute stuff). > > The command: $(cat /dev/random) > is passed to the shell, where it does "command substitution" on > it first and then executes it, where "it" is the output of the > cat command, which could be destructive. > > Simpler tests are: > > pwd > echo pwd > $(echo pwd) > echo $(echo pwd) I think the backticks (and shell variables) actually send the output to a pipe, not the screen.
I use them in recursive shell scripts, on occasion, which are run by the cron daemon. Either technique can be a blessing ... or a curse, depending on how you use them. lane _______________________________________________ [email protected] mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to "[EMAIL PROTECTED]"
