网上搜了一下，
1. 先是写了一个脚本
#!/bin/bash [ -d $1 ] && { for f in $(find $1 -type l) do if [ ! -e "$f" ]; then echo "rm $f" rm -f $f fi done }
2. 再简化成命令行：
for f in $(find $1 -type l); do [ ! -e $f ] && rm -f $f; done
3. 后来再搜，发现执行个命令即可：symlinks -d
symlinks: scan/change symbolic links - v1.2 - by Mark Lord
Usage: symlinks [-crsv] dirlist
Flags: -c == change absolute/messy links to relative
-d == delete dangling links
-r == recurse into subdirs
-s == shorten lengthy links (only displayed if -c not specified)
-v == verbose (show all symlinks)
