LSFD(1) LSFD(1) lsfd - lsfd [] lsfd lsof(8) . lsof lsfd (namespaces) . lsfd lsof . . . --output columns-list . lsfd Libsmartcols . --output --filter . lsfd --list-columns . -l --threads (threads). -J --json JSON. -n --noheadings . -o --output . OUTPUT COLUMNS . + (: lsfd -o +DELETED). -r --raw . --notruncate . -p, --pid list . list PID . FILTER EXAMPLES. -i[4|6], --inet[=4|=6] IPv4 / IPv6 . -Q, --filter expression expression. scols-filter(5) FILTER EXAMPLES. -Q PID (: -Q PID==1) -p (: -p 1) -p -Q. -C --counter :_ --summary. lsfd . lsfd _ . lsfd --filter . scols-filter(5) filter_expr. label { : . . COUNTER EXAMPLES. --summary[=mode] . mode only append never. mode only . . . --counter . lsfd ( ) . : --summary --json . --summary=only --json . --debug-filter . lsfd . --dump-counters --summary. --hyperlink[=] . always never auto. auto . -H --list-columns --output. --json --raw . -h --help . -V --version . LIBSMARTCOLS_DEBUG=all libsmartcols. LIBSMARTCOLS_DEBUG_PADDING=on . . < >. : . . AINODECLASS <_> inode . ASSOC <_> . BLKDRV <_> /proc/devices. BPF-MAP.ID <> Bpf. BPF-MAP.TYPE <_> bpf. BPF-MAP.TYPE.RAW <> Bpf (). BPF.NAME <_> Bpf. BPF-PROG.ID <> Bpf. BPF-PROG.TAG <_> Bpf. BPF-PROG.TYPE <_> bpf. BPF-PROG.TYPE.RAW <> Bpf (). CHRDRV <_> /proc/devices. COMMAND <_> . DELETED <> . DEV <_> . DEVTYPE <_> (blk char nodev). ENDPOINTS <_> IPC fd. lsfd lsfd lsfd -p. fd: FIFO, mqueue, ptmx pts PID,COMMAND,ASSOC[-r][-w] ([-r][-w]) / . eventfd PID,COMMAND,ASSOC UNIX UNIX-STREAM. lsfd ENDPOINTS. lsfd sock_diag(7) UNIX. SELinux sock_diag . 1 virt_sandbox_use_netlink. container_selinux(8) . UNIX-STREAM PID,COMMAND,ASSOC[-r?][-w?] ([-r?][-w?]) SOCK.SHUTDOWN. EVENTFD.ID <> Eventfd. EVENTPOLL.TFDS <_> eventpoll. FD <> . FLAGS <_> . FUID <> . INET.LADDR <_> IP . INET.RADDR <_> IP . INET6.LADDR <_> IP6 . INET6.RADDR <_> IP6 . INODE <> (Inode). INOTIFY.INODES <_> INOTIFY.INODES.RAW. --,--. INOTIFY.INODES.RAW <_> . --,-:-. KNAME <_> /proc/-/fd/fd /proc/-/map_files/region. KTHREAD <> . MAJ:MIN <_> . MAPLEN <> (). MISCDEV <_> /proc/misc. MNTID <> . MODE <_> (rwx). NAME <_> KNAME. KNAME . : AF_VSOCK state=SOCK.STATE type=SOCK.TYPE laddr=VSOCK.LADDR[ raddr=VSOCK.RADDR] raddr . bpf-map id=BPF-MAP.ID type=BPF-MAP.TYPE[ name=BPF.NAME] bpf-prog id=BPF-PROG.ID type=BPF-PROG.TYPE tag= BPF-PROG.TAG [ name=BPF.NAME] eventpoll tfds=EVENTPOLL.TFDS eventfd id=EVENTFD.ID inotify inodes=INOTIFY.INODES misc:tun iface=TUN.IFACE[ devnetns=TUN.DEVNETNS][ socknetns=SOCK.NETNS] NETLINK protocol=NETLINK.PROTOCOL[ lport=NETLINK.LPORT[ group=NETLINK.GROUPS]] PACKET type=SOCK.TYPE[ protocol=PACKET.PROTOCOL][ iface=PACKET.IFACE] pidfd pid=TARGET-PID comm=TARGET-COMMAND nspid=TARGET-NSPIDS lsfd TARGET-PID TARGET-NSPIDS /proc/-/fdinfo/fd. PING state=SOCK.STATE[ id=PING.ID][ laddr=INET.LADDR [ raddr=INET.RADDR]] PINGv6 state=SOCK.STATE[ id=PING.ID][ laddr=INET6.LADDR [ raddr=INET6.RADDR]] ptmx tty-index=PTMX.TTY-INDEX lsfd PTMX.TTY-INDEX /proc/-/fdinfo/fd. RAW state=SOCK.STATE[ protocol=RAW.PROTOCOL [ laddr=INET.LADDR [ raddr=INET.RADDR]]] RAWv6 state=SOCK.STATE[ protocol=RAW.PROTOCOL [ laddr=INET6.LADDR [ raddr=INET6.RADDR]]] signalfd mask=SIGNALFD.MASK TCP, TCPv6 state=SOCK.STATE[ laddr=TCP.LADDR [ raddr=TCP.RADDR]] timerfd clockid=TIMERFD.CLOCKID[ remaining=TIMERFD.REMAINING [ interval=TIMERFD.INTERVAL]] UDP, UDPv6 state=SOCK.STATE[ laddr=UDP.LADDR [ raddr=UDP.RADDR]] lsfd raddr= UDP.RADDR 0.0.0.0 UDP.RPORT 0. UDP-LITE, UDPLITEv6 state=SOCK.STATE[ laddr=UDPLITE.LADDR [ raddr=UDPLITE.RADDR]] UNIX-STREAM state=SOCK.STATE[ path=UNIX.PATH] UNIX state=SOCK.STATE[ path=UNIX.PATH] type=SOCK.TYPE (deleted) . KNAME DELETED XMODE . NETLINK.GROUPS <> Netlink . NETLINK.LPORT <> Netlink . NETLINK.PROTOCOL <_> Netlink. NLINK <> . NS.NAME <_> (NS.TYPE:[INODE]) . NS.TYPE <_> . mnt cgroup uts ipc user pid net time unknown. OWNER <_> . PACKET.IFACE <_> (packet socket). PACKET.PROTOCOL <_> L2 ( ). PACKET.PROTOCOL.RAW <> L2 (). PARTITION <_> /proc/partition. PID <> (PID) . PIDFD.COMM <_> pidfd. PIDFD.NSPID <_> NSpid /proc/-/fdinfo/fd pidfd. kernel/fork.c : pid pid pidfd pid pid Pid NSpid . Pid NSpid /proc//status Pid NSpid pid procfs. PIDFD.PID <> (PID) pidfd. PING.ID <`number`> ICMP PING. POS <> . RAW.PROTOCOL < > ( ). Note <> v2.39 v2.41. RAW.PROTOCOL.RAW <> (). RDEV <_> ( ). SIGNALFD.MASK <_> . SIZE <> . SOCK.LISTENING <> . SOCK.NETS <> (inode) . SOCK.PROTONAME <_> . SOCK.SHUTDOWN <_> . [-r?] r . - . ? . [-w?] w . - . ? . SOCK.STATE <_> . SOCK.TYPE <_> . socket: o stream o dgram o raw o rdm o seqpacket o dccp o packet SOURCE <_> . ERROR TYPE lsfd syscall:_errno_. STTYPE <_> stat(2): BLK CHR DIR FIFO LINK REG SOCK UNKN. TCP.LADDR <_> L3 (INET.LADDR INET6.LADDR) TCP . TCP.LPORT <> TCP . TCP.RADDR <_> L3 (INET.RADDR INET6.RADDR) TCP . TCP.RPORT <> TCP . TID <> (Thread ID) . TIMERFD.CLOCKID <_> Clockid. TIMERFD.INTERVAL <> . TIMERFD.REMAINING <> . PTMX.TTY-INDEX <> TTY . TUN.DEVNETNS <> (inode) . TUN.IFACE <_> tun. TYPE <_> STTYPE. STTYPE . SOCK SOCK.PROTONAME. UNKN AINODECLASS SOURCE anon_inodefs. lsfd lsfd ERROR. UDP.LADDR <_> IP UDP . UDP.LPORT <> UDP . UDP.RADDR <_> IP UDP . UDP.RPORT <> UDP . UDPLITE.LADDR <_> IP UDPLite . UDPLITE.LPORT <> UDP . UDPLITE.RADDR <_> IP UDPLite . UDPLITE.RPORT <> UDP . UID <> . UNIX.IPEER < > Inode UNIX. lsfd UNIX.IPEER. UNIX ENDPOINTS . UNIX.PATH <_> UNIX. USER <_> . VSOCK.LADDR <_>, VSOCK.RADDR <_> VSOCK . VSOCK.LCID:VSOCK.LPORT. (CIDs) : "*" "hypervisor" "local" "host". : "*". VSOCK.LCID <>, VSOCK.RCID <> VSOCK . VSOCK.LPORT <>, VSOCK.RPORT <> VSOCK . XMODE <_> MODE. XMODE lsfd / . [-r] . MODE. [-w] . MODE. [-x] . MODE. [-D] . DELETED. [-Ll] . l . L . / / L . [-m] (Multiplexed). eventpoll (select(2) pselect(2) poll(2) ppoll(2)) . lsfd m . restart_syscall(2). lsfd . -Q ( --filter). -o ( --output) . PID 1 PID 2: # lsfd -Q '(PID == 1) or (PID == 2)' : # lsfd -Q '(PID == 1) || (PID == 2)' : # lsfd --pid 1,2 : # lsfd --pid '1 2' pidof(1) "firefox": # lsfd --pid "$(pidof firefox)" PID 1: # lsfd -Q '(PID == 1) and (FD == 1)' : # lsfd -Q '(PID == 1) && (FD == 1)' : # lsfd -Q 'ASSOC == "exe"' : # lsfd -Q 'ASSOC eq "exe"' : # lsfd -o NAME -Q 'ASSOC eq "exe"' | sort -u : # lsfd -Q 'DELETED' : # lsfd -Q 'TYPE != "REG"' : # lsfd -Q 'DEVTYPE == "blk"' TYPE: # lsfd -Q 'TYPE == "BLK"' "dconf" : # lsfd -Q 'NAME =~ ".\*/dconf/.*"' QEMU : # lsfd -Q '(COMMAND =~ ".\*qemu.*") and (FD >= 0)' timerfd 0.5 : # lsfd -Q '(TIMERFD.remaining < 0.5) and (TIMERFD.remaining > 0.0)' unix stream: # lsfd -Q 'TYPE == "UNIX-STREAM" && UNIX.PATH =~ ".+"' -oUNIX.PATH,PID,COMMAND,FD,SOCK.STATE,ENDPOINTS unix stream : # lsfd -Q 'TYPE == "UNIX-STREAM" && UNIX.PATH == "@/tmp/.X11-unix/X0"' -oUNIX.PATH,PID,COMMAND,FD,SOCK.STATE,ENDPOINTS netlink unix: # lsfd --summary=only \ -C 'netlink sockets':'(NAME =~ "NETLINK:.*")' \ -C 'unix sockets':'(NAME =~ "UNIX:.*")' VALUE COUNTER 57 netlink sockets 1552 unix sockets JSON: # lsfd --summary=only --json \ -C 'netlink sockets':'(NAME =~ "NETLINK:.*")' \ -C 'unix sockets':'(NAME =~ "UNIX:.*")' { "lsfd-summary": [ { "value": 15, "counter": "netlink sockets" },{ "value": 798, "counter": "unix sockets" } ] } lsfd util-linux v2.38. Masatake YAMATO Karel Zak bpftool(8) bps(8) lslocks(8) lsof(8) pidof(1) proc(5) scols-filter(5) socket(2) ss(8) stat(2) vsock(7) . lsfd util-linux . util-linux 2.42.1 2026-05-18 LSFD(1)