Add --bare option to pyenv version (#2783)

COMMANDS.md

@@ -272,8 +272,15 @@ version of Python, or install a package that provides binaries.
 Displays the currently active Python version, along with information on
 how it was set.
 
+    Usage: pyenv version [--bare]
+
+    --bare    show just the version name. An alias to `pyenv version-name'
+
+
     $ pyenv version
     2.7.6 (set by /home/yyuu/.pyenv/version)
+    $ pyenv version --bare
+    2.7.6
 
 
 ## `pyenv versions`

libexec/pyenv-version

@@ -1,9 +1,8 @@
 #!/usr/bin/env bash
 # Summary: Show the current Python version(s) and its origin
+# Usage: pyenv version [--bare]
 #
-# Shows the currently selected Python version(s) and how it was
+#     --bare    show just the version name. An alias to `pyenv version-name'
-# selected. To obtain only the version string, use `pyenv
-# version-name'.
 
 set -e
 [ -n "$PYENV_DEBUG" ] && set -x
@@ -13,8 +12,25 @@ OLDIFS="$IFS"
 IFS=: PYENV_VERSION_NAMES=($(pyenv-version-name)) || exitcode=$?
 IFS="$OLDIFS"
 
+unset bare
+for arg; do
+    case "$arg" in
+        --complete )
+            echo --bare
+            exit ;;
+        --bare ) bare=1 ;;
+        * )
+          pyenv-help --usage version >&2
+          exit 1
+          ;;
+    esac
+done
 for PYENV_VERSION_NAME in "${PYENV_VERSION_NAMES[@]}"; do
+  if [[ -n $bare ]]; then
+      echo "$PYENV_VERSION_NAME"
+  else
       echo "$PYENV_VERSION_NAME (set by $(pyenv-version-origin))"
+  fi
 done
 
 exit $exitcode

test/version.bats

@@ -70,3 +70,12 @@ pyenv-version-without-stderr() {
 3.3.3 (set by PYENV_VERSION environment variable)
 OUT
 }
+
+@test "--bare prints just the name" {
+  create_version "3.3.3"
+  PYENV_VERSION=3.3.3 run pyenv-version --bare
+  assert_success
+  assert_output <<OUT
+3.3.3
+OUT
+}