Fix fish installation instructions (#1916)

README.md

@@ -216,12 +216,20 @@ easy to fork and contribute any changes back upstream.
      ~~~
 
    - For **Fish shell**:
+
+     Execute this interactively:
      ~~~ fish
      set -Ux PYENV_ROOT $HOME/.pyenv
-     set -Ux fish_user_paths $PYENV_ROOT/bin $fish_user_paths
+     set -U fish_user_paths $PYENV_ROOT/bin $fish_user_paths
-     pyenv init --path | source
      ~~~
 
+     And add this to `~/.config/fish/config.fish`:
+     ~~~ fish
+     status is-login; and pyenv init --path | source
+     ~~~
+
+     If fish is not your login shell, also follow the bash/zsh instructions to add to ~/.profile.
+
    - **Proxy note**: If you use a proxy, export `http_proxy` and `https_proxy` too.
 
 3. **Add `pyenv init` to your shell** to enable shims and autocompletion.
@@ -239,8 +247,9 @@ easy to fork and contribute any changes back upstream.
      ~~~
 
    - For **Fish shell**:
+     Add this to `~/.config/fish/config.fish`:
      ~~~ fish
-     echo -e '\n\n# pyenv init\nif command -v pyenv 1>/dev/null 2>&1\n  pyenv init - | source\nend' >> ~/.config/fish/config.fish
+     pyenv init - | source
      ~~~
 
     **General warning**: There are some systems where the `BASH_ENV` variable is configured

libexec/pyenv-init

@@ -83,50 +83,49 @@ function help_() {
   ksh )
     profile='~/.profile'
     ;;
-  fish )
-    profile='~/.config/fish/config.fish'
-    ;;
   * )
     profile='your profile'
     ;;
   esac
 
-  { echo "# Add pyenv executable to PATH by adding"
+  {
-    echo "# the following to ~/.profile:"
-    echo
     case "$shell" in
     fish )
+      echo "# Add pyenv executable to PATH by running"
+      echo "# the following interactively:"
+      echo
       echo 'set -Ux PYENV_ROOT $HOME/.pyenv'
-      echo 'set -Ux fish_user_paths $PYENV_ROOT/bin $fish_user_paths'
+      echo 'set -U fish_user_paths $PYENV_ROOT/bin $fish_user_paths'
-      ;;
+      echo
-    * )
+      echo "# Load pyenv automatically by appending"
+      echo "# the following to ~/.config/fish/config.fish:"
+      echo
+      echo 'status is-login; and pyenv init --path | source'
+      echo 'pyenv init - | source'
+      echo
+      echo "# If fish is not your login shell,"
+      echo "# add the following to ~/.profile:"
+      echo
       echo 'export PYENV_ROOT="$HOME/.pyenv"'
       echo 'export PATH="$PYENV_ROOT/bin:$PATH"'
+      echo 'eval "$(pyenv init --path)"'
+      echo
       ;;
-    esac
+    * )
+      echo "# Add pyenv executable to PATH by adding"
+      echo "# the following to ~/.profile:"
+      echo
+      echo 'export PYENV_ROOT="$HOME/.pyenv"'
+      echo 'export PATH="$PYENV_ROOT/bin:$PATH"'
       echo
       echo "# Load pyenv automatically by appending"
       echo "# the following to ${profile}:"
       echo
-    case "$shell" in
-    fish )
-      echo 'pyenv init - | source'
-      ;;
-    * )
       echo 'eval "$(pyenv init -)"'
-      ;;
-    esac
       echo
       echo "# and the following to ~/.profile:"
       echo
-    case "$shell" in
-    fish )
-      echo 'pyenv init --path | source'
-      ;;
-    * )
       echo 'eval "$(pyenv init --path)"'
-      ;;
-    esac
       echo
       echo '# If your ~/.profile sources '"${profile}"','
       echo '# the lines should be inserted before the part'
@@ -135,6 +134,8 @@ function help_() {
       echo '# Make sure to restart your entire logon session'
       echo '# for changes to ~/.profile to take effect.'
       echo
+      ;;
+    esac
   } >&2
 }