On Tue, Jun 26, 2018 at 5:01 PM Jeff King <peff@xxxxxxxx> wrote: > On Tue, Jun 26, 2018 at 04:46:18PM -0400, Eric Sunshine wrote: > > Some of these dangers can be de-thoothed during the linting phase by > > defining do-nothing shell functions: > > > > cp () { :; } > > mv () { :; } > > ln () { :; } > > > > That, at least, makes the scariest case ("rm") much less so. > > Now that's an interesting idea. We can't catch every dangerous action > (notably ">" would be hard to override), but it should be pretty cheap > to cover some obvious ones. Taking the idea a bit further, the 'sed' script could also throw away strings of "../" inside subshells, which would help defang the more difficult cases, like "echo x >../git.c". There are pathological cases, of course, which it wouldn't catch: P=../git.c test_expect_success 'foo' ' ( cd dir && echo x >$P ) ' but it does help mitigate the issue for the most typical cases.