On Tue, Oct 10, 2006 at 06:14:22PM -0500, mwoehlke wrote: [...] > >$ zsh -c 'echo "`/dev/null 2>&1`"' bash > >bash: /dev/null: Permission denied > > > >$ zsh > >$ ARGV0=bash ash -c 'echo "`/dev/null 2>&1`"; echo $BASH' > >bash: /dev/null: Permission denied > > Eh? I get: > > $ zsh -c 'echo "`/dev/null 2>&1`"' bash > zsh:1: permission denied: /dev/null
Well, I do get what I said with zsh 4.3.2 > $ ARGV0=bash ash -c 'echo "`/dev/null 2>&1`"; echo $BASH' > /dev/null: permission denied (note that this command must be run from zsh which uses ARGV0=... to set ash's argv[0]). You must have an older /ash/ than I have mine is one of the OpenBSD based sh ones (found on debian). > > So neither of your counter-examples is working for me (although both > look like they *should*; go figure). Though I'd bet the third one with .zshenv worked. > But since you didn't counter > BASH_SUBSHELL (and since I'm too lazy to change it now) I guess I'll > stick with that. :-) BASH_SUBSHELL is a relatively recent addition to bash. Most systems still don't have a bash3. $ bash -c 'echo "$BASH_VERSION, <$BASH_SUBSHELL>"' 2.05b.0(2)-release, <> [...] > True, but the main point of the exercise is to go with a check that's > unlikely to be worked around "by accident". If someone intentionally > circumvents the check (and you're right, editing the script would be > easy), well then they deserve whatever happens. But I *am* paranoid > enough to not trust that $BASH is never set - other than by bash - for > some reason. Or that it hasn't been *unset* (since that seems to kill it > forever), because we have 'clean environment' scripts that would do this > sort of thing. [...] Then I'd go with $BASH_VERSION as someone else suggested which is in every bash version. -- Stéphane _______________________________________________ Bug-bash mailing list Bug-bash@gnu.org http://lists.gnu.org/mailman/listinfo/bug-bash
