Usage: fuser [ -a | -s | -c ] [ -n SPACE ] [ -SIGNAL ] [ -kimuv ] NAME...
             [ - ] [ -n SPACE ] [ -SIGNAL ] [ -kimuv ] NAME...
       fuser -l
       fuser -V
Show which processes use the named files, sockets, or filesystems.

    -a        display unused files too
    -c        mounted FS
    -f        silently ignored (for POSIX compatibility)
    -i        ask before killing (ignored without -k)
    -k        kill processes accessing the named file
    -l        list available signal names
    -m        show all processes using the named filesystems
    -n SPACE  search in this name space (file, udp, or tcp)
    -s        silent operation
    -SIGNAL   send this signal instead of SIGKILL
    -u        display user IDs
    -v        verbose output
    -V        display version information
    -4        search IPv4 sockets only
    -6        search IPv6 sockets only
    -         reset options

  udp/tcp names: [local_port][,[rmt_host][,[rmt_port]]]

用于查看指定哪些进程正在访问指定目录