updated doc

SYSTEM.md

@@ -5,21 +5,25 @@
 `binenv` can be installed system-wide, so binaries are managed for the entire
 system.
 
-In this mode, `binenv` is installed in `/opt/binenv`, followinf the
-[FHS](https://en.wikipedia.org/wiki/Filesystem_Hierarchy_Standard).
+In this mode, `binenv` is installed in several system-wide places:
+
+- `cachedir`, holding the distributions cache, in `/var/cache/binenv`
+- `confdir`, holding the distributions list, in `/var/lib/binenv`
+- `linkdir`, holding symlinks to the shim, in `/usr/local/bin/`
+- `bindir`, holding shim and distributions binaries
 
 Users in the system will be able to use any binary installed this way. However,
 only `root` will be able to manage binaries.
 
-To use `binenv` in this global mode, the `-g` flag is required before each command, e.g.:
+To use `binenv` in this global mode, the `-g` flag is required before each
+command, e.g.:
 
 ```bash
 sudo binenv -g install terraform
 ```
 
 To run in global mode, you can either install from [scratch](#installation), or
-[move](#migrate-user-installation-to-system-wide) an existing user
-installation.
+[add](#add-system-wide-installation) a system wide installation.
 
 Note that operations that mutate state (i.e. `install`, `uninstall`, `update`,
 `upgrade`) will have to be executed as `root`.
@@ -41,8 +45,6 @@ rm ./binenv_linux_amd64
 if [[ -n $BASH ]]; then ZESHELL=bash; fi
 if [[ -n $ZSH_NAME ]]; then ZESHELL=zsh; fi
 echo $ZESHELL
-echo -e '\nexport PATH=/opt/binenv/:$PATH' >> ~/.${ZESHELL}rc
-echo -e '\nexport PATH=/opt/binenv/:$PATH' | sudo tee -a /root/.${ZESHELL}rc
 echo "source <(binenv completion ${ZESHELL})" >> ~/.${ZESHELL}rc
 exec $SHELL
 ```
@@ -57,8 +59,6 @@ chmod +x binenv_darwin_amd64
 sudo ./binenv_darwin_amd64 -g update
 sudo ./binenv_darwin_amd64 -g install binenv
 rm ./binenv_darwin_amd64 
-echo -e '\nexport PATH=/opt/binenv/:$PATH' >> ~/.bashrc
-echo -e '\nexport PATH=/opt/binenv/:$PATH' | sudo tee -a /root/.${ZESHELL}rc
 echo 'source <(binenv completion bash)' >> ~/.bashrc
 exec $SHELL
 ```
@@ -80,8 +80,6 @@ rm ./binenv_freebsd_amd64
 if [[ -n $BASH ]]; then ZESHELL=bash; fi
 if [[ -n $ZSH_NAME ]]; then ZESHELL=zsh; fi
 echo $ZESHELL
-echo -e '\nexport PATH=/opt/binenv/:$PATH' >> ~/.${ZESHELL}rc
-echo -e '\nexport PATH=/opt/binenv/:$PATH' | sudo tee -a /root/.${ZESHELL}rc
 echo "source <(binenv completion ${ZESHELL})" >> ~/.${ZESHELL}rc
 exec $SHELL
 ```
@@ -103,95 +101,33 @@ rm ./binenv_openbsd_amd64
 if [[ -n $BASH ]]; then ZESHELL=bash; fi
 if [[ -n $ZSH_NAME ]]; then ZESHELL=zsh; fi
 echo $ZESHELL
-echo -e '\nexport PATH=/opt/binenv/:$PATH' >> ~/.${ZESHELL}rc
-echo -e '\nexport PATH=/opt/binenv/:$PATH' | sudo tee -a /root/.${ZESHELL}rc
 echo "source <(binenv completion ${ZESHELL})" >> ~/.${ZESHELL}rc
 exec $SHELL
 ```
 
 If you are using a different shell, skip adding completion to your `.${SHELL}rc` file.
 
-## Migrate user installation to system wide
-
-This is not really recommended. But if you have bandwidth constraints and do
-not want to re-download everything, you can do it like so:
-
-- replace `~/.binenv` with `/opt/binenv` in your shell rcfile (`~/.bashrc` or
-  `~/.zshrc`)
-- create `/opt/binenv` with proper permissions
-
-```bash
-sudo mkdir -m 755 /opt/binenv
-```
+## Add system-wide installation
 
-- copy cache and config
+- Ensure you are using at least `binenv` version v0.19.0.
 
 ```bash
-sudo cp -aR ~/.config/binenv/ /opt/binenv/config
-sudo cp -aR ~/.cache/binenv/ /opt/binenv/cache
+binenv version
 ```
 
-- copy binaries in `/opt/binenv`
+- install `binenv` system-wide
 
 ```bash
-sudo cp -aR ~/.binenv/* /opt/binenv/
+binenv -g install binenv
 ```
 
-- recreate symlinks
-
-```bash
-for i in $(find /opt/binenv/ -type l); do 
-    sudo ln -sf /opt/binenv/shim $i
-done
-```
-
-## Caveats
-
-On Debian systems, PATH is reset by sudo. So calling `sudo binenv` (or other
-installed binaries with `sudo`) will not work. To fix this, you have 3 options
-(spoiler: none of them is perfect):
-
-### change `secure_path` in `/etc/sudoers`
-
-Replace the line:
-
-`Defaults	secure_path="/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/snap/bin"`
-
-with:
-
-`Defaults	secure_path="/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/snap/bin:/opt/binenv"`
-
-### pass env variables when calling sudo
-
-```bash
-sudo env "PATH=$PATH binenv" -g install foo
-```
-
-You can also do something like `alias sudo='sudo env "PATH=$PATH binenv"'` if
-you're lazy, but this is not really recommended.
-
-### use the full path
-
-```bash
-sudo /opt/binenv/binenv -g install yq
-```
-
-## FAQ
-
-### Why not install in `/usr/local/bin` ?
-
-`binenv` makes quite a mess and is quite opinionated in the way it handles
-things. Having the bin directory in `/usr/local/bin/` is a recipe for a
-disaster.
+- adjust path in your rcfiles according to your preferences
 
 ### Why do I have to use `-g` ? Can't binenv autodetect global mode ?
 
 Yes it could. But what if you want to use a user installation along a global
 one ? Say, for instance, when your sysadmin does not want to install a specific
 binary.
 
-If you point to `/opt/binenv/binenv`, you will have to use separated `binenv`
-binaries to manage your own install. Probably a PITA.
-
 The best way to achieve this is to `export BINENV_GLOBAL=true` in your shell
 rc-file so binenv will always run in global mode.