n fails when there is no internet access and other semi-related issues

[sine9]

Hello n developers! I love n and use it to quickly switch versions of node for testing.

I was on a plane recently no internet access and n stopped working. After seeing that you needed to specify the exact version number, I attempted to write a shell script wrapper and found other issues worth noting. They are all listed here:

1. there seems to be no way to tell n to use the latest available for a given semver description if internet access is not available. To test this, try turning off your internet and running

$ sudo n 7
$ sudo n 7.
$ sudo n 7.x

All of these fail. The only thing that worked was running n and pulling the exact version number.

2. a version number with an asterisk fails with some cp errors:

$ sudo n 7.*.*
cp: /usr/local/n/versions/node/7.*.*/bin: No such file or directory
cp: /usr/local/n/versions/node/7.*.*/lib: No such file or directory
cp: /usr/local/n/versions/node/7.*.*/include: No such file or directory
cp: /usr/local/n/versions/node/7.*.*/share: No such file or directory

n probably should just fail rather than attempt a command.

3. n ls gives blank input when there is no internet connection. I can understand why, since "available" is determined by comparing against a list that is unavailable when internet is off, but since n can switch between installed versions n ls should show only the installed versions when internet access is not available.

4. There is no command to just get a plaintext list of the installed versions. n is an interactive tool, redirecting to file or pipe screws with the shell session. n ls shows in bold but it's difficult to work with that programmatically. Some TTY detection logic may be necessary.

5. the n list sorts the 0.10 and 0.12 series before the 0.8 series. That seems to be a bug that will rear its ugly head again if 6.10 is reached.

6. How do I remove all older minor or patch versions of node? For example, my computer has a bunch of older node versions and I would like to prune to the latest patch version of the given major version:

    node/0.8.28

    node/0.9.12

    node/0.10.46 <-- remove
    node/0.10.47 <-- remove
    node/0.10.48

    node/0.11.16

    node/0.12.15 <-- remove
    node/0.12.16 <-- remove
    node/0.12.17 <-- remove
    node/0.12.18

    node/4.5.0 <-- remove
    node/4.6.0 <-- remove
    node/4.6.2 <-- remove
    node/4.7.0 <-- remove
    node/4.7.1

    node/5.12.0

    node/6.1.0 <-- remove
    node/6.8.0 <-- remove
    node/6.9.1 <-- remove
    node/6.9.2 <-- remove
    node/6.9.3 <-- remove
    node/6.9.4

    node/7.0.0 <-- remove
    node/7.2.1 <-- remove
    node/7.3.0 <-- remove
  ο node/7.4.0

[troy0820]

n prune will remove old versions of node on your system as of n 2.1.6

[shadowspawn]

There were a lot of interesting comments here, thanks @sine9.

I came across this issue again, so a status update for future readers.

1. offline: no change (I think of the menu as a good option for offline)
2. 7.*.*: now considered invalid
3. listing: n ls now lists local versions
4. plain text: n ls displays plain text
5. sorting: fixed (and did eventually cause problems before it was fixed!)
6. major version prune: no change, came up again in Feature: "n upgrade" for upgrading major versions #568