fnm

配置#

Windows#

powershell

fnm env --use-on-cd --version-file-strategy=recursive --corepack-enabled --resolve-engines --shell powershell | Out-String | Invoke-Expression

fnm env --use-on-cd --version-file-strategy=recursive --corepack-enabled --resolve-engines --shell powershell | Out-String | Invoke-Expression

powershell

[System.Environment]::SetEnvironmentVariable("FNM_NODE_DIST_MIRROR", "https://npmmirror.com/mirrors/node/", "User")[System.Environment]::SetEnvironmentVariable("COREPACK_NPM_REGISTRY", "https://registry.npmmirror.com", "User")

[System.Environment]::SetEnvironmentVariable("FNM_NODE_DIST_MIRROR", "https://npmmirror.com/mirrors/node/", "User")[System.Environment]::SetEnvironmentVariable("COREPACK_NPM_REGISTRY", "https://registry.npmmirror.com", "User")

缓存补全脚本#

fnm completions 生成的脚本约 42 KB，每次启动重新生成要 30 ms。它只随 fnm 二进制变化，缓存起来即可：

powershell

$__f = "$HOME\.cache\pwsh\fnm-completions.ps1"$__src = (Get-Command fnm -ErrorAction SilentlyContinue).Sourceif ($__src -and ((-not (Test-Path $__f)) -or (Get-Item $__src).LastWriteTime -gt (Get-Item $__f).LastWriteTime)) {    fnm completions --shell powershell | Out-String | Set-Content $__f -Encoding utf8}if (Test-Path $__f) { . $__f }

$__f = "$HOME\.cache\pwsh\fnm-completions.ps1"$__src = (Get-Command fnm -ErrorAction SilentlyContinue).Sourceif ($__src -and ((-not (Test-Path $__f)) -or (Get-Item $__src).LastWriteTime -gt (Get-Item $__f).LastWriteTime)) {    fnm completions --shell powershell | Out-String | Set-Content $__f -Encoding utf8}if (Test-Path $__f) { . $__f }

fnm env 不能这样处理 —— 它必须每次执行，为当前会话创建 multishell 目录。

multishell 目录会一直堆积#

每开一个 shell，fnm 都会在 %LOCALAPPDATA%\fnm_multishells 下建一个目录， Windows 上退出时不清理，会一直累积。

它们是 junction，本身几乎不占空间，但目录数多了会拖慢遍历。清理陈旧的：

powershell

$cut = (Get-Date).AddDays(-1)Get-ChildItem "$env:LOCALAPPDATA\fnm_multishells" -Directory |    Where-Object { $_.CreationTime -lt $cut } |    Remove-Item -Recurse -Force

$cut = (Get-Date).AddDays(-1)Get-ChildItem "$env:LOCALAPPDATA\fnm_multishells" -Directory |    Where-Object { $_.CreationTime -lt $cut } |    Remove-Item -Recurse -Force

删 junction 不会动到目标 —— %APPDATA%\fnm\node-versions 下的 node 安装是安全的。统计这个目录的体积时要注意：Get-ChildItem -Recurse 会穿透 junction，把同一份 node 重复计上千遍，看起来像几个 GB，实际并没有。

macOS 同样会堆积，位置是 ~/.local/state/fnm_multishells。那边是符号链接， du -sh 显示 0B，所以不占空间，但条目数会无限增长。

按 PID 清理比按时间准#

目录名的格式是 <PID>_<时间戳>，所以可以直接判断创建它的 shell 还在不在，这样不会误删今天开着的会话：

d=~/.local/state/fnm_multishells        # Windows: $env:LOCALAPPDATA\fnm_multishellsfor e in "$d"/*; do  n=$(basename "$e")  [ -L "$e" ] || continue               # 只处理链接  case "$n" in [0-9]*_[0-9]*) ;; *) continue;; esac  [ "$e" = "$FNM_MULTISHELL_PATH" ] && continue   # 当前会话在用的绝不能删  kill -0 "${n%%_*}" 2>/dev/null || rm -f "$e"done

d=~/.local/state/fnm_multishells        # Windows: $env:LOCALAPPDATA\fnm_multishellsfor e in "$d"/*; do  n=$(basename "$e")  [ -L "$e" ] || continue               # 只处理链接  case "$n" in [0-9]*_[0-9]*) ;; *) continue;; esac  [ "$e" = "$FNM_MULTISHELL_PATH" ] && continue   # 当前会话在用的绝不能删  kill -0 "${n%%_*}" 2>/dev/null || rm -f "$e"done

PID 可能被复用，最坏情况只是漏删一个，不会误删活着的。

但这个判据有个盲区：祖先已退出、后代还在跑。子进程会继承父进程的 PATH，所以一个「创建者已死」的目录，可能仍被某个长期运行的进程（编辑器的集成终端、 agent 的会话、tmux/herdr 里的 pane）引用着。删掉之后那些进程里 node 会直接消失：

echo $PATH | tr ':' '\n' | grep fnm_multishells | while read -r p; do  [ -e "$p" ] || echo "已失效: $p"done

echo $PATH | tr ':' '\n' | grep fnm_multishells | while read -r p; do  [ -e "$p" ] || echo "已失效: $p"done

稳妥做法是两个条件都满足才删 —— 进程已退出，且创建时间超过一天：

find "$d" -maxdepth 1 -type l -mtime +1 | while read -r e; do  n=$(basename "$e")  case "$n" in [0-9]*_[0-9]*) ;; *) continue;; esac  [ "$e" = "$FNM_MULTISHELL_PATH" ] && continue  kill -0 "${n%%_*}" 2>/dev/null || rm -f "$e"done

find "$d" -maxdepth 1 -type l -mtime +1 | while read -r e; do  n=$(basename "$e")  case "$n" in [0-9]*_[0-9]*) ;; *) continue;; esac  [ "$e" = "$FNM_MULTISHELL_PATH" ] && continue  kill -0 "${n%%_*}" 2>/dev/null || rm -f "$e"done

真误删了也不严重：新开的 shell 会重新生成，受影响的进程重启一下即可。

MacOS/Linux#

eval "$(fnm env --use-on-cd --version-file-strategy=recursive --corepack-enabled --resolve-engines)"

eval "$(fnm env --use-on-cd --version-file-strategy=recursive --corepack-enabled --resolve-engines)"

export FNM_NODE_DIST_MIRROR="https://npmmirror.com/mirrors/node/"export COREPACK_NPM_REGISTRY="https://registry.npmmirror.com"

export FNM_NODE_DIST_MIRROR="https://npmmirror.com/mirrors/node/"export COREPACK_NPM_REGISTRY="https://registry.npmmirror.com"