A Unix annoyance
Unix: where you have to escape command line arguments twice, once from the shell and once from the program.
I dearly love Unix, but I am forced to admit that every so often it
has what I can only describe as 'robot logic'; things that are
perfectly logical, but not to normal humans. For example, consider the
fun of trying to remove a file called something like "-Brad Foo
".
$ rm -Brad Foo rm: invalid option -- B $ rm "-Brad Foo" rm: invalid option -- B $ rm ./-Brad Foo rm: cannot remove `./-Brad': No such file or directory rm: cannot remove `Foo': No such file or directory
(and so on.)
Of course this is happening because the arguments are processed twice;
once by the shell to determine what's a single argument and what gets
split up, and then again by rm
itself to find its options. So you
have to escape the filename in the shell because it has a space in it,
and that's entirely separate from how rm
normally thinks anything
starting with a dash is a switch, not a filename to be removed. (And
programs can be wildly inconsistent in how to escape their arguments.)
I've used Unix sufficiently long and deeply that that I can see and explain all of this in my sleep. It all makes perfect sense and it's completely consistent and logical (once you understand Unix's logic).
But let's be honest here: it's robot logic, not human logic.
(This entry is inspired by the travails of a perfectly technically
adept Unix person in a similar situation, as recounted
here. He had a
simpler example that didn't need being escaped from the shell, just
from rm
.)
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