Re:Use long flags when scripting (2013)
by a1369209993 on Saturday September 19, 2020 @02:41AM
(#24525652)
> It means that `test -d $argv` expands to `test -d` if $argv is empty, which then must "succeed" because "-d" is not null. It bites users over and over again [2].
To be fair, while the POSIX behaviour is obviously wrong, using `$argv` on a bourne-style shell[0] is also wrong; that should be either `test -d "$argv"` or (if I recall the syntax correctly) `test -d "${argv[@]}"` if you actually intended argv to be a list rather than a single directory ("argv" suggests the former, but `test -d X` only accepts a single argument).
0: more specifically, a shell that does word splitting at the wrong place (after parameter expansion)
To be fair, while the POSIX behaviour is obviously wrong, using `$argv` on a bourne-style shell[0] is also wrong; that should be either `test -d "$argv"` or (if I recall the syntax correctly) `test -d "${argv[@]}"` if you actually intended argv to be a list rather than a single directory ("argv" suggests the former, but `test -d X` only accepts a single argument).
0: more specifically, a shell that does word splitting at the wrong place (after parameter expansion)