The previous behavior of the remotes completion was that only
alphanumeric characters were allowed in a remote name. This limitation
has been lifted somewhat by #2985, which also allowed an underscore.
With the new implementation introduced in this commit, the completion of
the remote name has been simplified: If there is no colon (":") in the
current word, then complete remote name. Otherwise, complete the path
inside the specified remote. This allows correct completion of all
remote names that are allowed by the config (including - and _).
Actually it matches much more than that, even remote names that are not
allowed by the config, but in such a case there already would be a wrong
identifier in the configuration file.
With this simpler string comparison, we can get rid of the regular
expression, which makes the completion multiple times faster. For a
sample benchmark, try the following:
# Old way
$ time bash -c 'for _ in {1..1000000}; do
[[ remote:path =~ ^[[:alnum:]]*$ ]]; done'
real 0m15,637s
user 0m15,613s
sys 0m0,024s
# New way
$ time bash -c 'for _ in {1..1000000}; do
[[ remote:path != *:* ]]; done'
real 0m1,324s
user 0m1,304s
sys 0m0,020s
Before this change, rclone used the `__custom_func` hook to control
the completions of remote files. However this clashes with other
cobra users, the most notable example being kubectl.
Upgrading cobra to master allows us to use a namespaced function
`__rclone_custom_func` which fixes the problem.
Fixes#1529
Instead of showing all flags/backends all the time, you can type
rclone help flags
rclone help flags <regexp>
rclone help backends
rclone help backend <name>