Date: Tue, 26 Jul 2005 18:03:43 -0700 From: garys@opusnet.com (Gary W. Swearingen) To: Michael Beattie <mtbeedee@gmail.com> Cc: Lane <lane@joeandlane.com>, freebsd-questions@freebsd.org Subject: Re: cat /dev/urandom Message-ID: <ehhdehys9c.deh@mail.opusnet.com> In-Reply-To: <d4b4435a0507261647325c336c@mail.gmail.com> (Michael Beattie's message of "Tue, 26 Jul 2005 19:47:42 -0400") References: <20050726183029.M97284@neptune.atopia.net> <200507261807.23024.lane@joeandlane.com> <d4b4435a050726161858d838a@mail.gmail.com> <200507261849.46220.lane@joeandlane.com> <d4b4435a0507261647325c336c@mail.gmail.com>
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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)
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