lsof(8)

lsof
-  -r <s> ..... repeatedly execute command ervery <s> seconds
-  -a ......... AND slection filters instead ORing (OR: default)
-  -p <pid> ... filter by <pid>
-  +fg ........ show file flags for file descripros
-  -n ......... don't convert network addr to hostnames
-  -P ......... don't convert network port to service names
-  -i <@h[:p]>. show connections to h (hostname|ip addr) with optional port p
-  -s <p:s> ... in conjunction with '-i' filter for protocol <p> in state <s>
-  -U ......... show unix domain sockets ('@' indicates abstract sock name, see unix(7))
-

file flags:
-  R/W/RW ..... read/write/read-write
-  CR ......... create
-  AP ......... append
-  TR ......... truncate
-

-s protocols
-  TCP, UDP
-
--s states (TCP)
-  CLOSED, IDLE, BOUND, LISTEN, ESTABLISHED, SYN_SENT, SYN_RCDV, ESTABLISHED,
-  CLOSE_WAIT, FIN_WAIT1, CLOSING, LAST_ACK, FIN_WAIT_2, TIME_WAIT
-
--s states (UDP)
-  Unbound, Idle
-

Examples

File flags

Show open files with file flags for process:

lsof +fg -p <pid>
-

Open TCP connections

Show open tcp connections for $USER:

lsof -a -u $USER -i TCP
-

Note: -a ands the results. If -a is not given all open files matching -$USER and all tcp connections are listed (ored).

Open connection to specific host

Show open connections to localhost for $USER:

lsof -a -u $USER -i @localhost
-

Open connection to specific port

Show open connections to port :1234 for $USER:

lsof -a -u $USER -i :1234
-

IPv4 TCP connections in `ESTABLISHED` state

lsof -i 4TCP -s TCP:ESTABLISHED
-

List open files in a mounted directory.

This may help to find which processes keep devices busy when trying to unmount -and the device is currently busy.

# Assuming /proc is a mount point.
-lsof /proc
-

- -

pgrep [opts] <pattern> - -n only list newest matching process - -u <usr> only show matching for user <usr> - -l additionally list command - -a additionally list command + arguments - -x match exactly -

pidstat [opt] [interval] [cont] - -U [user] show username instead UID, optionally only show for user - -r memory statistics - -d I/O statistics - -h single line per process and no lines with average -

pidstat -r -p <pid> [interval] [count] -

minor_pagefault: Happens when the page needed is already in memory but not - allocated to the faulting process, in that case the kernel - only has to create a new page-table entry pointing to the - shared physical page (not required to load a memory page from - disk). - -major_pagefault: Happens when the page needed is NOT in memory, the kernel - has to create a new page-table entry and populate the - physical page (required to load a memory page from disk). -

pmap [opts] <pid> - Dump virtual memory map of process. - Compared to /proc/<pid>/maps it shows the size of the mappings. -opts: - -p show full path in the mapping - -x show details (eg RSS usage of each segment) -

ps [opt] - opt: - --no-header .... do not print column header - -o <OUT> ....... comma separated list of output columns - -p <PID> ....... only show pid - -C <name> ...... only show processes matching name - -T ............. list threads - --signames ..... use short signames instead bitmasks -

Set PS_FORMAT env variable to setup default output columns.

Frequently used output columns

pid process id -ppid parent process id -pgid process group id -tid thread id - -comm name of process -cmd name of process + args (full) - -etime elapsed time (since process started) -user user owning process -thcount thread count of process -nice nice value (-20 highest priority to 19 lowest) - -pcpu cpu utilization (percent) -pmem physical resident set (rss) (percent) -rss physical memory (in kb) -vsz virtual memory (in kb) - -sig mask of pending signals -sigcatch mask of caught signals -sigignore mask of ignored signals -sigmask mask of blocked signals -

Notes

Resource analysis & monitor

Notes

lsof(8)

Examples

File flags

Open TCP connections

Open connection to specific host

Open connection to specific port

IPv4 TCP connections in `ESTABLISHED` state

List open files in a mounted directory.

Notes

pgrep(1)

Debug newest process

Notes

pidstat(1)

Page fault and memory utilization

I/O statistics

Notes

pmap(1)

Notes

ps(1)

Example: Use output for scripting

Example: Watch processes by name

Example: Show signal information

Notes

pstack(1)