[New] add prune command

README.md

@@ -37,6 +37,7 @@
   - [io.js](#iojs)
   - [System Version of Node](#system-version-of-node)
   - [Listing Versions](#listing-versions)
+  - [Pruning old versions](#pruning-old-versions)
   - [Setting Custom Colors](#setting-custom-colors)
     - [Persisting custom colors](#persisting-custom-colors)
     - [Suppressing colorized output](#suppressing-colorized-output)
@@ -576,6 +577,21 @@ If you want to see what versions are available to install:
 nvm ls-remote
 ```
 
+### Pruning old versions
+
+To clean up old, unused Node.js versions, use `nvm prune`:
+
+```sh
+nvm prune
+```
+
+This will uninstall all installed versions except for the latest one within each major version group (e.g., if you have `v16.1.0` and `v16.2.0`, it will keep `v16.2.0`).
+
+- **Safety**: The currently active version is **never** removed, even if it is not the latest in its group.
+- **Global Modules**: `nvm prune` will warn you if it's about to uninstall a version that contains global npm modules (other than `npm` itself).
+- **Preview**: Use `nvm prune --dry-run` to see which versions would be removed without actually uninstalling them.
+- **Minor Version Retention**: Use `nvm prune --minor` to keep the latest version of each **minor** release group instead of major.
+
 ### Setting Custom Colors
 
 You can set five colors that will be used to display version and alias information. These colors replace the default colors.

nvm.sh

@@ -2005,6 +2005,177 @@ nvm_ls_remote() {
   NVM_LTS="${NVM_LTS-}" nvm_ls_remote_index_tab node std "${PATTERN}"
 }
 
+nvm_prune() {
+  local NVM_DRY_RUN
+  NVM_DRY_RUN=0
+  local KEEP_MINOR
+  KEEP_MINOR=0
+  local ARG
+  for ARG in "$@"; do
+    case "${ARG}" in
+      --dry-run)
+        NVM_DRY_RUN=1
+        ;;
+      --minor)
+        KEEP_MINOR=1
+        ;;
+      *)
+        nvm_err "Unknown argument: ${ARG}"
+        return 127
+        ;;
+    esac
+  done
+
+  if [ "${NVM_DEBUG-}" = 1 ]; then
+    nvm_echo "Pruning old installed versions..."
+    if [ "${NVM_DRY_RUN}" -eq 1 ]; then
+      nvm_echo "Dry run mode: no versions will be removed."
+    fi
+  fi
+
+  local HAS_SORT_V
+  HAS_SORT_V=0
+  if command sort -V </dev/null >/dev/null 2>&1; then
+    HAS_SORT_V=1
+  fi
+
+  local AWK_CMD
+  AWK_CMD='{
+    if ($1 == "system") next
+    for(i=1;i<=NF;i++) {
+      if ($i ~ /^(iojs-)?v[0-9]+\.[0-9]+\.[0-9]+$/) {
+        sub(/^iojs-/, "", $i)
+        print $i
+      }
+    }
+  }'
+
+  local VERSIONS
+  if [ "${HAS_SORT_V}" -eq 1 ]; then
+    VERSIONS="$(nvm_ls | command awk "${AWK_CMD}" | command sort -V)"
+  else
+    # Fallback to numeric sort on fields roughly for POSIX compliance
+    # v1.2.3 -> field 1 (1.2n ignores 'v'), field 2, field 3
+    VERSIONS="$(nvm_ls | command awk "${AWK_CMD}" | command sort -t. -k 1.2,1n -k 2,2n -k 3,3n)"
+  fi
+
+  if [ -z "${VERSIONS}" ]; then
+    nvm_echo "No versions installed to prune."
+    return 0
+  fi
+
+  # Ensure the current version is stripped of iojs prefix to match our clean list
+  local CURRENT_VERSION
+  CURRENT_VERSION="$(nvm_strip_iojs_prefix "$(nvm_ls_current)")"
+  if [ "${CURRENT_VERSION}" = "system" ] || [ "${CURRENT_VERSION}" = "none" ]; then
+    CURRENT_VERSION=""
+  fi
+
+  local PREV_MAJOR
+  PREV_MAJOR=""
+  local GROUP_VERSIONS
+  GROUP_VERSIONS=""
+
+  # Append a dummy line to flush the last group
+  VERSIONS="${VERSIONS}
+END"
+
+  nvm_is_zsh && setopt local_options shwordsplit
+  local IFS
+  IFS='
+'
+  # shellcheck disable=SC2013
+  for VERSION in ${VERSIONS}; do
+    unset IFS
+    local MAJOR
+    MAJOR=""
+    if [ "${VERSION}" != "END" ] && [ -n "${VERSION}" ]; then
+      if [ "${KEEP_MINOR}" -eq 1 ]; then
+        MAJOR="$(nvm_echo "${VERSION}" | command cut -d. -f1,2)"
+      else
+        MAJOR="$(nvm_echo "${VERSION}" | command cut -d. -f1)"
+      fi
+    fi
+
+    if [ "${MAJOR}" != "${PREV_MAJOR}" ] && [ -n "${PREV_MAJOR}" ]; then
+      # Process previous group
+      local LATEST_IN_GROUP
+      # Get the last word in GROUP_VERSIONS
+      LATEST_IN_GROUP=""
+      for V in ${GROUP_VERSIONS}; do
+        LATEST_IN_GROUP="${V}"
+      done
+
+      for V in ${GROUP_VERSIONS}; do
+        if [ "${V}" = "${LATEST_IN_GROUP}" ]; then
+          # It's the latest, keep it
+          # nvm_echo "Keeping latest: ${V}"
+          continue
+        fi
+        if [ "${V}" = "${CURRENT_VERSION}" ]; then
+          if [ "${NVM_DEBUG-}" = 1 ]; then
+            nvm_echo "Keeping current version: ${V}"
+          fi
+          continue
+        fi
+
+        # Re-resolve if the version is actually iojs
+        local UNINSTALL_V
+        UNINSTALL_V="${V}"
+        if ! nvm_is_version_installed "${UNINSTALL_V}" >/dev/null 2>&1; then
+          local IOJS_V
+          IOJS_V="$(nvm_add_iojs_prefix "${V}")"
+          if nvm_is_version_installed "${IOJS_V}" >/dev/null 2>&1; then
+            UNINSTALL_V="${IOJS_V}"
+          fi
+        fi
+
+        if ! nvm_is_version_installed "${UNINSTALL_V}" >/dev/null 2>&1; then
+          continue
+        fi
+
+        # Check for global npm modules explicitly
+        local NODE_MODULES_DIR
+        NODE_MODULES_DIR="$(nvm_version_path "${UNINSTALL_V}")/lib/node_modules"
+        local HAS_GLOBALS
+        HAS_GLOBALS=0
+        if [ -d "${NODE_MODULES_DIR}" ]; then
+          local NUM_GLOBALS
+          NUM_GLOBALS="$(command ls -1 "${NODE_MODULES_DIR}" 2>/dev/null | nvm_grep -v '^npm$' | command wc -l | command awk '{print $1}')"
+          if [ "${NUM_GLOBALS}" -gt 0 ]; then
+            HAS_GLOBALS="${NUM_GLOBALS}"
+          fi
+        fi
+
+        local MSG_SUFFIX
+        MSG_SUFFIX=""
+        if [ "${HAS_GLOBALS}" -gt 0 ]; then
+          MSG_SUFFIX=" (Warning: replacing ${HAS_GLOBALS} global module(s))"
+        fi
+
+        # Prune V
+        if [ "${NVM_DRY_RUN}" -eq 1 ]; then
+          nvm_echo "[Dry Run] Uninstalling ${UNINSTALL_V}...${MSG_SUFFIX}"
+        else
+          nvm_echo "Uninstalling ${UNINSTALL_V}...${MSG_SUFFIX}"
+          nvm uninstall "${UNINSTALL_V}" >/dev/null
+        fi
+      done
+
+      GROUP_VERSIONS=""
+    fi
+
+    if [ "${VERSION}" = "END" ]; then
+      break
+    fi
+
+    if [ -n "${VERSION}" ]; then
+      PREV_MAJOR="${MAJOR}"
+      GROUP_VERSIONS="${GROUP_VERSIONS} ${VERSION}"
+    fi
+  done
+}
+
 nvm_ls_remote_iojs() {
   NVM_LTS="${NVM_LTS-}" nvm_ls_remote_index_tab iojs std "${1-}"
 }
@@ -3956,6 +4127,9 @@ nvm() {
         nvm_echo '  nvm uninstall <version>                     Uninstall a version'
         nvm_echo '  nvm uninstall --lts                         Uninstall using automatic LTS (long-term support) alias `lts/*`, if available.'
         nvm_echo '  nvm uninstall --lts=<LTS name>              Uninstall using automatic alias for provided LTS line, if available.'
+        nvm_echo '  nvm prune                                   Uninstall all versions except the latest one for each major version.'
+        nvm_echo '    --dry-run                                 Preview deletions without executing them.'
+        nvm_echo '    --minor                                   Uninstall all versions except the latest one for each minor version.'
         nvm_echo '  nvm use [current | <version>]               Modify PATH to use <version>. Uses .nvmrc if version is omitted; otherwise errors.'
         nvm_echo '   The following optional arguments, if provided, must appear directly after `nvm use`:'
         nvm_echo '    --silent                                  Silences stdout/stderr output'
@@ -4673,6 +4847,9 @@ nvm() {
         nvm unalias "$(command basename "${ALIAS}")"
       done
     ;;
+    "prune")
+      nvm_prune "$@"
+    ;;
     "deactivate")
       local NVM_SILENT
       while [ $# -ne 0 ]; do
@@ -5460,6 +5637,7 @@ nvm() {
         nvm_get_artifact_compression nvm_install_binary_extract nvm_extract_tarball \
         nvm_process_nvmrc nvm_process_nvmrc_content nvm_nvmrc_invalid_msg \
         nvm_write_nvmrc nvm_hash_reset \
+        nvm_prune \
         >/dev/null 2>&1
       unset NVM_NODEJS_ORG_MIRROR NVM_IOJS_ORG_MIRROR NVM_DIR \
         NVM_CD_FLAGS NVM_BIN NVM_INC NVM_MAKE_JOBS NVM_INSTALL_LOCK \

test/fast/Running 'nvm prune' should remove old versions

@@ -0,0 +1,97 @@
+#!/bin/sh
+
+# Test: Running 'nvm prune' should remove old versions
+
+die () { echo "$@" ; exit 1; }
+
+# Mocking nvm_ls output logic relies on nvm_ls calling directory listing.
+# Instead of mocking filesystem which is complex, we will override nvm_ls and nvm_ls_current.
+
+. ../../nvm.sh
+
+# Mock nvm_ls to return specific versions as if they were installed
+# The implementation of nvm_prune calls: nvm_ls --no-colors --no-alias
+# We must mock nvm_ls to respond to that or just return the list.
+# Note: nvm_prune strips output except vX.Y.Z.
+nvm_ls() {
+  echo "       v16.20.2"
+  echo "       v18.20.5"
+  echo "       v18.20.7"
+  echo "       v20.17.0"
+  echo "->     v22.22.0"
+  echo "       v24.13.0"
+}
+
+# Mock nvm_ls_current
+nvm_ls_current() {
+  echo "v22.22.0"
+}
+
+# Mock nvm_is_version_installed
+nvm_is_version_installed() {
+  return 0
+}
+
+# Mock nvm function to intercept uninstall calls
+# nvm_prune calls `nvm uninstall`.
+UNINSTALLED_VERSIONS=""
+nvm() {
+  if [ "$1" = "uninstall" ]; then
+    UNINSTALLED_VERSIONS="${UNINSTALLED_VERSIONS} $2"
+    return 0
+  fi
+  echo "nvm called with unexpected args: $*"
+}
+
+# Run prune
+nvm_prune
+
+# Expected:
+# v16.20.2 (Keep: Only one v16)
+# v18.20.5 (Delete: v18.20.7 is newer) -> WAIT. v18.20.7 is newer. So keep 18.20.7. Delete 18.20.5.
+# v18.20.7 (Keep: Latest v18)
+# v20.17.0 (Keep: Only one v20)
+# v22.22.0 (Keep: Current)
+# v24.13.0 (Keep: Only one v24)
+
+# Wait, my logic for nvm_prune was to keep latest per major.
+# v18.20.5 and v18.20.7 are Major 18.
+# Latest is v18.20.7.
+# So v18.20.5 should be pruned.
+
+# Check UNINSTALLED_VERSIONS
+EXPECTED=" v18.20.5"
+if [ "${UNINSTALLED_VERSIONS}" != "${EXPECTED}" ]; then
+  die "Expected uninstalled: '${EXPECTED}', got: '${UNINSTALLED_VERSIONS}'"
+fi
+
+# New Test Case: Current version is NOT the latest.
+# v18.1.0 (Current)
+# v18.2.0 (Latest)
+# v18.0.0 (Old)
+
+nvm_ls() {
+  echo "       v18.0.0"
+  echo "->     v18.1.0"
+  echo "       v18.2.0"
+}
+
+nvm_ls_current() {
+  echo "v18.1.0"
+}
+
+UNINSTALLED_VERSIONS=""
+nvm_prune
+
+# Expected:
+# v18.0.0 (Prune)
+# v18.1.0 (Keep: Current)
+# v18.2.0 (Keep: Latest)
+
+EXPECTED=" v18.0.0"
+
+if [ "${UNINSTALLED_VERSIONS}" != "${EXPECTED}" ]; then
+  die "TestCase 2 Failed. Expected uninstalled: '${EXPECTED}', got: '${UNINSTALLED_VERSIONS}'"
+fi
+
+echo "All tests passed"