From e8ad78f8379766dcd0a94ca5e6dd703f82e5a714 Mon Sep 17 00:00:00 2001
From: Yamashita Yuu <yamashita@geishatokyo.com>
Date: Wed, 3 Oct 2012 12:19:42 +0900
Subject: [PATCH] add `pyenv push` and `pyenv pop` to manage version stack

---
 README.md             | 28 ++++++++++++++++++++++++++++
 libexec/pyenv-sh-pop  | 18 ++++++++++++++++++
 libexec/pyenv-sh-push | 14 ++++++++++++++
 3 files changed, 60 insertions(+)
 create mode 100755 libexec/pyenv-sh-pop
 create mode 100755 libexec/pyenv-sh-push

diff --git a/README.md b/README.md
index 86fce0b0..e253b47a 100644
--- a/README.md
+++ b/README.md
@@ -199,6 +199,20 @@ within these Python versions are searched by specified order.
     $ pyenv which python
     /home/yyuu/.pyenv/versions/2.7.3/bin/python
 
+You can manage your version stack by `pyenv push` and `pyenv pop`.
+
+    $ pyenv global
+    2.7.3
+    3.2.3
+    $ pyenv push 3.3.0
+    $ pyenv global
+    2.7.3
+    3.2.3
+    3.3.0
+    $ pyenv pop
+    2.7.3
+    3.2.3
+
 ### <a name="section_3.2"></a> 3.2 pyenv local
 
 Sets a local per-project Python version by writing the version name to
@@ -228,6 +242,20 @@ within these Python versions are searched by specified order.
     $ pyenv which python
     /home/yyuu/.pyenv/versions/2.7.3/bin/python
 
+You can manage your version stack by `pyenv push` and `pyenv pop`.
+
+    $ pyenv local
+    2.7.3
+    3.2.3
+    $ pyenv push 3.3.0
+    $ pyenv local
+    2.7.3
+    3.2.3
+    3.3.0
+    $ pyenv pop
+    2.7.3
+    3.2.3
+
 ### <a name="section_3.3"></a> 3.3 pyenv shell
 
 Sets a shell-specific Python version by setting the `PYENV_VERSION`
diff --git a/libexec/pyenv-sh-pop b/libexec/pyenv-sh-pop
new file mode 100755
index 00000000..944422d3
--- /dev/null
+++ b/libexec/pyenv-sh-pop
@@ -0,0 +1,18 @@
+#!/usr/bin/env bash
+set -e
+[ -n "$PYENV_DEBUG" ] && set -x
+
+IFS=: versions=($(pyenv-version-name))
+
+length="${#versions[@]}"
+PYENV_VERSION_NAMES=()
+for ((i=0; i<length-1; i++)); do
+  PYENV_VERSION_NAMES=("${PYENV_VERSION_NAMES[@]}" "${versions[$i]}")
+done
+
+if [ -n "$PYENV_VERSION" ]; then
+  IFS=: PYENV_VERSION="${PYENV_VERSION_NAMES[*]}"
+  echo "export PYENV_VERSION=\"${PYENV_VERSION}\""
+else
+  pyenv-version-file-write "$(pyenv-version-file)" "${PYENV_VERSION_NAMES[@]}"
+fi
diff --git a/libexec/pyenv-sh-push b/libexec/pyenv-sh-push
new file mode 100755
index 00000000..5ab3ee33
--- /dev/null
+++ b/libexec/pyenv-sh-push
@@ -0,0 +1,14 @@
+#!/usr/bin/env bash
+set -e
+[ -n "$PYENV_DEBUG" ] && set -x
+
+IFS=: PYENV_VERSION_NAMES=($(pyenv-version-name))
+versions=("$@")
+PYENV_VERSION_NAMES=("${PYENV_VERSION_NAMES[@]}" "${versions[@]}")
+
+if [ -n "$PYENV_VERSION" ]; then
+  IFS=: PYENV_VERSION="${PYENV_VERSION_NAMES[*]}"
+  echo "export PYENV_VERSION=\"${PYENV_VERSION}\""
+else
+  pyenv-version-file-write "$(pyenv-version-file)" "${PYENV_VERSION_NAMES[@]}"
+fi