Merge pull request #372 from sstephenson/exec-next

Change `exec` semantics to allow using rbenv from a ruby process

libexec/rbenv-exec

@@ -2,24 +2,59 @@
 #
 # Summary: Run an executable with the selected Ruby version
 #
-# Usage: rbenv exec <command> [arg1 arg2...]
+# Usage: rbenv exec <command> [args...]
 #
-# Runs an executable by first preparing PATH so that the selected Ruby
-# version's `bin' directory is at the front.
+# Runs an executable contained by the currently selected Ruby's bin
+# directory. Rough equivalent of:
 #
-# For example, if the currently selected Ruby version is 1.9.3-p327:
-#   rbenv exec bundle install
-#
-# is equivalent to:
-#   PATH="$RBENV_ROOT/versions/1.9.3-p327/bin:$PATH" bundle install
+#   exec "$(rbenv prefix)/bin/$command" args...
 
 set -e
 [ -n "$RBENV_DEBUG" ] && set -x
 
+rubypath=""
 # Provide rbenv completions
-if [ "$1" = "--complete" ]; then
-  exec rbenv shims --short
-fi
+while true; do
+  case "$1" in
+  "--complete" )
+    exec rbenv shims --short
+    ;;
+  "--rubypath" )
+    rubypath=1
+    shift 1
+    ;;
+  * )
+    break
+    ;;
+  esac
+done
+
+# Replace any "RBENV_ROOT/shims" or "RBENV_ROOT/versions/*/bin" paths in the
+# list with the given path. If no replacements were made, prepend the path onto
+# the list.
+replace_shims_path() {
+  local path="$1"
+  local dir="$2"
+  # fake directory that serves as a placeholder for shims location in RUBYPATH:
+  local placeholder="/rbenv_shims_were_here"
+  local found=""
+  local result=""
+  local -a paths
+  IFS=: paths=($path)
+
+  for path in "${paths[@]}"; do
+    if [[ $path = "${RBENV_ROOT}/shims" || $path == "${RBENV_ROOT}/versions/"*/bin || $path = $placeholder ]]; then
+      found=1
+      result="${result}${dir:-$placeholder}:"
+    else
+      result="${result}${path}:"
+    fi
+  done
+
+  # if no rbenv paths were replaced, simply prepend the path
+  [ -n "$found" -o -z "$dir" ] || result="${dir}:${path}"
+  echo "${result%:}"
+}
 
 RBENV_VERSION="$(rbenv-version-name)"
 RBENV_COMMAND="$1"
@@ -31,7 +66,6 @@ fi
 
 export RBENV_VERSION
 RBENV_COMMAND_PATH="$(rbenv-which "$RBENV_COMMAND")"
-RBENV_BIN_PATH="${RBENV_COMMAND_PATH%/*}"
 
 OLDIFS="$IFS"
 IFS=$'\n' scripts=(`rbenv-hooks exec`)
@@ -41,7 +75,9 @@ for script in "${scripts[@]}"; do
 done
 
 shift 1
-if [ "$RBENV_VERSION" != "system" ]; then
-  export PATH="${RBENV_BIN_PATH}:${PATH}"
+if [ -n "$rubypath" ]; then
+  bindir=""
+  [ "$RBENV_VERSION" != "system" ] && bindir="${RBENV_COMMAND_PATH%/*}"
+  export RUBYPATH="$(replace_shims_path "${RUBYPATH:-$PATH}" "$bindir")"
 fi
 exec -a "$RBENV_COMMAND" "$RBENV_COMMAND_PATH" "$@"

libexec/rbenv-rehash

@@ -45,10 +45,12 @@ create_prototype_shim() {
 set -e
 [ -n "\$RBENV_DEBUG" ] && set -x
 
+opt=""
 program="\${0##*/}"
 if [ "\$program" = "ruby" ]; then
   for arg; do
     case "\$arg" in
+    -S* ) opt=--rubypath ;;
     -e* | -- ) break ;;
     */* )
       if [ -f "\$arg" ]; then
@@ -61,7 +63,7 @@ if [ "\$program" = "ruby" ]; then
 fi
 
 export RBENV_ROOT="$RBENV_ROOT"
-exec "$(command -v rbenv)" exec "\$program" "\$@"
+exec "$(command -v rbenv)" exec \$opt "\$program" "\$@"
 SH
   chmod +x "$PROTOTYPE_SHIM_PATH"
 }