fix: Handle problems caused by the tmux function in install.sh masking the tmux binary itself

[gkc]

Fixes #761

- What I did

• fix: install.sh: Handle problems caused by the tmux function masking the tmux binary itself
• fix: install.sh:
  • When copying binaries during installation, rename existing binaries as they may be in use (which is a problem in, for example, Windows)
  • Exit the install script if either the rename of existing or the copying of new binaries fails
• fix: install.sh: for installs using tmux, separate the handling of crontab installation from the handling of tmux process killing
• feat: install.sh: If the installation killed a process running as a tmux session, then also restart it

- How I did it

• See file diff
• Note that I didn't rename the tmux function but instead used command tmux whenever needing to use the tmux command itself
• While mulling over all of this, I came to the opinion that just killing an existing tmux session might be unhelpful and that it would be more helpful to restart the tmux session if there was one there to kill. However I preserve the current behaviour of not starting the tmux session if it is not already running.

[cconstab]

So I tried this in today and it failed to copy over sshnpd the first time it would seem. The second time worked fine see log below..

cconstab@orac:~/sshnp$ vi install.sh
cconstab@orac:~/sshnp$ ./install.sh tmux sshnpd
cconstab@orac:~/sshnp$
cconstab@orac:~/sshnp$
cconstab@orac:~/sshnp$
cconstab@orac:~/sshnp$ ~/.local/bin/sshnpd
-bash: /home/cconstab/.local/bin/sshnpd: No such file or directory
cconstab@orac:~/sshnp$ ./install.sh tmux sshnpd
=> Installed sshnpd to /home/cconstab/.local/bin
cconstab@orac:~/sshnp$ ~/.local/bin/sshnpd
Version : 5.0.1 (core: 6.0.1)
-k, --key-file,--keyFile              Sending atSign's keyFile if not in ~/.atsign/keys/
-a, --atsign (mandatory)              atSign of this device
-m, --manager (mandatory)             Managers atSign, that this device will accept triggers from
-d, --device                          Send a trigger to this device, allows multiple devices share an atSign
                                      (defaults to "default")
-s, --[no-]sshpublickey               When set, will update authorized_keys to include public key sent by manager
-u, --[no-]un-hide,--[no-]username    When set, makes various information visible to the manager atSign - e.g. username, version, etc
-v, --[no-]verbose                    More logging
    --ssh-client                      What to use for outbound ssh connections.
                                      [openssh (default), dart]
    --root-domain                     atDirectory domain
                                      (defaults to "root.atsign.org")
    --local-sshd-port                 port on which sshd is listening locally on localhost
                                      (defaults to "22")
    --ephemeral-permissions           The permissions which will be added to the authorized_keys file for the ephemeral public keys which are generated when a client is
                                      connecting via forward ssh e.g. PermitOpen="host-1:3389",PermitOpen="localhost:80"
                                      (defaults to "")
    --ssh-algorithm                   Use RSA 4096 keys rather than the default ED25519 keys
                                      [ssh-ed25519 (default), ssh-rsa]
    --storage-path                    Directory for local storage. Defaults to $HOME/.sshnp/${atSign}/storage

Invalid argument(s): Option atsign is mandatory.
cconstab@orac:~/sshnp$