Add --skip-aliases to pyenv virtualenvs (fixes #120)

bin/pyenv-virtualenvs

@@ -1,9 +1,9 @@
 #!/usr/bin/env bash
 #
 # Summary: List all Python virtualenvs found in `$PYENV_ROOT/versions/*'.
+# Usage: pyenv virtualenvs [--bare] [--skip-aliases]
 #
-# Usage: pyenv virtualenvs [--bare]
-#
+# List all virtualenvs found in `$PYENV_ROOT/versions/*' and its `$PYENV_ROOT/versions/envs/*'.
 
 set -e
 [ -n "$PYENV_DEBUG" ] && set -x
@@ -12,18 +12,80 @@ if [ -z "$PYENV_ROOT" ]; then
   PYENV_ROOT="${HOME}/.pyenv"
 fi
 
-if [ "$1" = "--bare" ]; then
+unset bare
+unset skip_aliases
+# Provide pyenv completions
+for arg; do
+  case "$arg" in
+  --complete )
+    echo --bare
+    echo --skip-aliases
+    exit ;;
+  --bare ) bare=1 ;;
+  --skip-aliases ) skip_aliases=1 ;;
+  * )
+    pyenv-help --usage virtualenvs >&2
+    exit 1
+    ;;
+  esac
+done
+
+versions_dir="${PYENV_ROOT}/versions"
+
+if ! enable -f "${BASH_SOURCE%/*}"/../libexec/pyenv-realpath.dylib realpath 2>/dev/null; then
+  if [ -n "$PYENV_NATIVE_EXT" ]; then
+    echo "pyenv: failed to load \`realpath' builtin" >&2
+    exit 1
+  fi
+
+  READLINK=$(type -p greadlink readlink | head -1)
+  if [ -z "$READLINK" ]; then
+    echo "pyenv: cannot find readlink - are you missing GNU coreutils?" >&2
+    exit 1
+  fi
+
+  resolve_link() {
+    $READLINK "$1"
+  }
+
+  realpath() {
+    local cwd="$PWD"
+    local path="$1"
+    local name
+
+    while [ -n "$path" ]; do
+      name="${path##*/}"
+      [ "$name" = "$path" ] || cd "${path%/*}"
+      path="$(resolve_link "$name" || true)"
+    done
+
+    echo "${PWD}/$name"
+    cd "$cwd"
+  }
+fi
+
+if [ -d "$versions_dir" ]; then
+  versions_dir="$(realpath "$versions_dir")"
+fi
+
+if [ -n "$bare" ]; then
   hit_prefix=""
   miss_prefix=""
   current_versions=()
   unset print_origin
+  include_system=""
 else
   hit_prefix="* "
   miss_prefix="  "
-  current_versions=($(IFS=:; for version in $(pyenv-version-name); do echo "$version"; done))
+  OLDIFS="$IFS"
+  IFS=: current_versions=($(pyenv-version-name || true))
+  IFS="$OLDIFS"
   print_origin="1"
+  include_system=""
 fi
 
+num_versions=0
+
 exists() {
   local car="$1"
   local cdar
@@ -42,21 +104,32 @@ print_version() {
   else
     echo "${miss_prefix}${1}${print_origin+$2}"
   fi
+  num_versions=$((num_versions + 1))
 }
 
 shopt -s nullglob
-for path in "${PYENV_ROOT}/versions/"*; do
-  version="${path##*/}"
-  virtualenv_prefix="$(pyenv-virtualenv-prefix "${version}" 2>/dev/null || true)"
-  if [ -d "${virtualenv_prefix}" ]; then
-    print_version "${version}" " (created from ${virtualenv_prefix})"
-  fi
-  for venv_path in "${path}/envs/"*; do
-    venv_version="${version}/envs/${venv_path##*/}"
-    virtualenv_prefix="$(pyenv-virtualenv-prefix "${venv_version}" 2>/dev/null || true)"
-    if [ -d "${virtualenv_prefix}" ]; then
-      print_version "${venv_version}" " (created from ${virtualenv_prefix})"
+for path in "$versions_dir"/*; do
+  if [ -d "$path" ]; then
+    if [ -n "$skip_aliases" ] && [ -L "$path" ]; then
+      target="$(realpath "$path")"
+      [ "${taget%/*/envs/*}" == "$versions_dir" ] || continue
     fi
-  done
+    virtualenv_prefix="$(pyenv-virtualenv-prefix "${path##*/}" 2>/dev/null || true)"
+    if [ -d "${virtualenv_prefix}" ]; then
+      print_version "${path##*/}" " (created from ${virtualenv_prefix})"
+    fi
+    for venv_path in "${path}/envs/"*; do
+      venv="${path##*/}/envs/${venv_path##*/}"
+      virtualenv_prefix="$(pyenv-virtualenv-prefix "${venv}" 2>/dev/null || true)"
+      if [ -d "${virtualenv_prefix}" ]; then
+        print_version "${venv}" " (created from ${virtualenv_prefix})"
+      fi
+    done
+  fi
 done
 shopt -u nullglob
+
+if [ "$num_versions" -eq 0 ] && [ -n "$include_system" ]; then
+  echo "Warning: no Python virtualenv detected on the system" >&2
+  exit 1
+fi