misc-utils/lsfd.1.adoc

   1 //po4a: entry man manual
   2 ////
   3 Copyright 2021 Red Hat, Inc.
   4
   5 This file may be copied under the terms of the GNU Public License.
   6 ////
   7 = lsfd(1)
   8 :doctype: manpage
   9 :man manual: User Commands
  10 :man source: util-linux {release-version}
  11 :page-layout: base
  12 :command: lsfd
  13 :colon: :
  14
  15 == NAME
  16
  17 lsfd - list file descriptors
  18
  19 == SYNOPSIS
  20
  21 *lsfd* [option]
  22
  23 == DESCRIPTION
  24
  25 *lsfd* is intended to be a modern replacement for *lsof*(8) on Linux systems.
  26 Unlike *lsof*, *lsfd* is specialized to Linux kernel; it supports Linux
  27 specific features like namespaces with simpler code. *lsfd* is not a
  28 drop-in replacement for *lsof*; they are different in the command line
  29 interface and output formats.
  30
  31 The default output is subject to change. So whenever possible, you should avoid using
  32 default outputs in your scripts. Always explicitly define expected columns by using
  33 *--output* _columns-list_ in environments where a stable output is required.
  34
  35 *lsfd* uses Libsmartcols for output formatting and filtering. See the description of *--output*
  36 option for customizing the output format, and *--filter* option for filtering. Use *lsfd --help*
  37 to get a list of all available columns.
  38
  39 == OPTIONS
  40
  41 *-l*, *--threads*::
  42 List in threads level.
  43
  44 *-J*, *--json*::
  45 Use JSON output format.
  46
  47 *-n*, *--noheadings*::
  48 Don't print headings.
  49
  50 *-o*, *--output* _list_::
  51 Specify which output columns to print. See the *OUTPUT COLUMNS*
  52 section for details of available columns.
  53 +
  54 The default list of columns may be extended if _list_ is specified in
  55 the format +_list_ (e.g., *lsfd -o +DELETED*).
  56
  57 *-r*, *--raw*::
  58 Use raw output format.
  59
  60 *--notruncate*::
  61 Don't truncate text in columns.
  62
  63 *-p*, *--pid* _pids_::
  64 Collect information only for specified processes.
  65 _pids_ is a list of pids. A comma or whitespaces can be used as separators.
  66 You can use this option with *pidof*(1). See *FILTER EXAMPLES*.
  67 +
  68 Both *-Q* option with an expression including PID, e.g. -Q (PID == 1),
  69 and *-p* option, e.g. -p 1, may print the same output but using *-p*
  70 option is much more efficient because *-p* option works at a much earlier
  71 stage of processing than the *-Q* option.
  72
  73 *-i*[4|6], *--inet*[=4|6]::
  74 List only IPv4 sockets and/or IPv6 sockets.
  75
  76 *-Q*, *--filter* _expr_::
  77 Print only the files matching the condition represented by the _expr_.
  78 See also *FILTER EXAMPLES*.
  79
  80 *-C*, *--counter* __label__:__filter_expr__::
  81 Define a custom counter used in *--summary* output. *lsfd* makes a
  82 counter named _label_. During collect information, *lsfd* counts files
  83 matching _filter_expr_, and stores the counted number to the
  84 counter named _label_. *lsfd* applies filters defined with *--filter*
  85 options before counting; files excluded by the filters are not counted.
  86 +
  87 See *FILTER EXPRESSION* about _filter_expr_.
  88 _label_ should not include `{` nor `:`. You can define multiple
  89 counters by specifying this option multiple times.
  90 +
  91 See also *COUNTER EXAMPLES*.
  92
  93 *--summary*[=_when_]::
  94 This option controls summary lines output. The optional argument _when_
  95 can be *only*, *append* or *never*. If the _when_ argument is omitted,
  96 it defaults to *only*.
  97 +
  98 The summary reports counters. A counter consists of a label and an
  99 integer value.  *--counter* is the option for defining a counter.  If
 100 a user defines no counter, *lsfd* uses the definitions of pre-defined
 101 built-in counters (default counters) to make the summary output.
 102 +
 103 CAUTION{colon} Using *--summary* and *--json* may make the output broken. Only combining *--summary*=*only* and *--json* is valid.
 104 //TRANSLATORS: Keep {colon} untranslated.
 105
 106 *--debug-filter*::
 107 Dump the internal data structure for the filter and exit. This is useful
 108 only for *lsfd* developers.
 109
 110 *--dump-counters*::
 111 Dump the definition of counters used in *--summary* output.
 112
 113 include::man-common/help-version.adoc[]
 114
 115 == OUTPUT COLUMNS
 116
 117 Each column has a type. Types are surround by < and >.
 118
 119 //TRANSLATORS: Keep {colon} untranslated.
 120 CAUTION{colon} The names and types of columns are not stable yet.
 121 They may be changed in the future releases.
 122
 123 AINODECLASS <``string``>::
 124 Class of anonymous inode.
 125
 126 ASSOC <``string``>::
 127 Association between file and process.
 128
 129 BLKDRV <``string``>::
 130 Block device driver name resolved by `/proc/devices`.
 131
 132 CHRDRV <``string``>::
 133 Character device driver name resolved by `/proc/devices`.
 134
 135 COMMAND <``string``>::
 136 Command of the process opening the file.
 137
 138 DELETED <``boolean``>::
 139 Reachability from the file system.
 140
 141 DEV <``string``>::
 142 ID of the device containing the file.
 143
 144 DEVTYPE <``string``>::
 145 Device type (`blk`, `char`, or `nodev`).
 146
 147 ENDPOINT <``string``>::
 148 IPC endpoints information communicated with the fd.
 149 +
 150 *lsfd* collects endpoints within the processes that
 151 *lsfd* scans; *lsfd* may miss some endpoints
 152 if you limits the processes with *-p* option.
 153 +
 154 The format of the column depends on the object associated
 155 with the fd:
 156
 157 FIFO type:::
 158 mqueue type:::
 159 _PID_,_COMMAND_,_ASSOC_[-r][-w]
 160 +
 161 The last characters ([-r][-w]) represents the read and/or
 162 write mode of the endpoint.
 163
 164 eventfd type:::
 165 _PID_,_COMMAND_,_ASSOC_
 166
 167 EVENTFD.ID <``number``>::
 168 Eventfd ID.
 169
 170 EVENTPOLL.TFDS <``string``>::
 171 File descriptors targeted by the eventpoll file.
 172
 173 FD <``number``>::
 174 File descriptor for the file.
 175
 176 FLAGS <``string``>::
 177 Flags specified when opening the file.
 178
 179 FUID <``number``>::
 180 User ID number of the file's owner.
 181
 182 INET.LADDR <``string``>::
 183 Local IP address.
 184
 185 INET.RADDR <``string``>::
 186 Remote IP address.
 187
 188 INET6.LADDR <``string``>::
 189 Local IP6 address.
 190
 191 INET6.RADDR <``string``>::
 192 Remote IP6 address.
 193
 194 INODE <``number``>::
 195 Inode number.
 196
 197 INOTIFY.INODES <``string``>::
 198 Cooked version of INOTIFY.INODES.RAW.
 199 The format of the element is
 200 _inode-number_,_source-of-inode_.
 201
 202 INOTIFY.INODES.RAW <``string``>::
 203 List of monitoring inodes. The format of the element
 204 is _inode-number_,_device-major_:_device-minor_.
 205
 206 KNAME <``string``>::
 207 //
 208 // It seems that the manpage backend of asciidoctor has limitations
 209 // about emitting text with nested face specifications like:
 210 //
 211 //   `_u_` p
 212 //
 213 // Not only u but also p is decorated with underline.
 214 //
 215 Raw file name extracted from
 216 from ``/proc/``_pid_``/fd/``_fd_ or ``/proc/``_pid_``/map_files/``_region_.
 217
 218 KTHREAD <``boolean``>::
 219 Whether the process is a kernel thread or not.
 220
 221 MAJ:MIN <``string``>::
 222 Device ID for special, or ID of device containing file.
 223
 224 MAPLEN <``number``>::
 225 Length of file mapping (in page).
 226
 227 MISCDEV <``string``>::
 228 Misc character device name resolved by `/proc/misc`.
 229
 230 MNTID <``number``>::
 231 Mount ID.
 232
 233 MODE <``string``>::
 234 Access mode (rwx).
 235
 236 NAME <``string``>::
 237 Cooked version of KNAME. It is mostly same as KNAME.
 238 +
 239 Some files have special formats and information sources:
 240 +
 241 eventpoll:::
 242 tfds=_EVENTPOLL.TFDS_
 243 +
 244 eventfd:::
 245 id=_EVENTFD.ID_
 246 +
 247 inotify:::
 248 iodes=_INOTIFY.INODES_
 249 +
 250 NETLINK:::
 251 protocol=_NETLINK.PROTOCOL_[ lport=_NETLINK.LPORT_[ group=_NETLINK.GROUPS_]]
 252 +
 253 PACKET:::
 254 type=_SOCK.TYPE_[ protocol=_PACKET.PROTOCOL_][ iface=_PACKET.IFACE_]
 255 +
 256 pidfd:::
 257 pid=_TARGET-PID_ comm=_TARGET-COMMAND_ nspid=_TARGET-NSPIDS_
 258 +
 259 *lsfd* extracts _TARGET-PID_ and _TARGET-NSPIDS_ from
 260 ``/proc/``_pid_``/fdinfo/``_fd_.
 261 +
 262 PING:::
 263 state=_SOCK.STATE_[ id=_PING.ID_][ laddr=_INET.LADDR_ [ raddr=_INET.RADDR_]]
 264 +
 265 PINGv6:::
 266 state=_SOCK.STATE_[ id=_PING.ID_][ laddr=_INET6.LADDR_ [ raddr=_INET6.RADDR_]]
 267 +
 268 RAW:::
 269 state=_SOCK.STATE_[ protocol=_RAW.PROTOCOL_ [ laddr=_INET.LADDR_ [ raddr=_INET.RADDR_]]]
 270 +
 271 RAWv6:::
 272 state=_SOCK.STATE_[ protocol=_RAW.PROTOCOL_ [ laddr=_INET6.LADDR_ [ raddr=_INET6.RADDR_]]]
 273 +
 274 signalfd:::
 275 mask=_SIGNALFD.MASK_
 276 +
 277 TCP:::
 278 TCPv6:::
 279 state=_SOCK.STATE_[ laddr=_TCP.LADDR_ [ raddr=_TCP.RADDR_]]
 280 +
 281 timerfd:::
 282 clockid=_TIMERFD.CLOCKID_[ remaining=_TIMERFD.REMAINING_ [ interval=_TIMERFD.INTERVAL_]]
 283 +
 284 UDP:::
 285 UDPv6:::
 286 state=_SOCK.STATE_[ laddr=_UDP.LADDR_ [ raddr=_UDP.RADDR_]]
 287 +
 288 *lsfd* hides ``raddr=`` if _UDP.RADDR_ is ``0.0.0.0`` and _UDP.RPORT_ is 0.
 289 +
 290 UDP-LITE:::
 291 UDPLITEv6:::
 292 state=_SOCK.STATE_[ laddr=_UDPLITE.LADDR_ [ raddr=_UDPLITE.RADDR_]]
 293 +
 294 UNIX-STREAM:::
 295 state=_SOCK.STATE_[ path=_UNIX.PATH_]
 296 +
 297 UNIX:::
 298 state=_SOCK.STATE_[ path=_UNIX.PATH_] type=_SOCK.TYPE_
 299
 300 NETLINK.GROUPS <``number``>::
 301 Netlink multicast groups.
 302
 303 NETLINK.LPORT <``number``>::
 304 Netlink local port id.
 305
 306 NETLINK.PROTOCOL <``string``>::
 307 Netlink protocol.
 308
 309 NLINK <``number``>::
 310 Link count.
 311
 312 NS.NAME <``string``>::
 313 Name (_NS.TYPE_:[_INODE_]) of the namespace specified with the file.
 314
 315 NS.TYPE <``string``>::
 316 Type of the namespace specified with the file.
 317 The type is `mnt`, `cgroup`, `uts`, `ipc`, `user`, `pid`, `net`,
 318 `time`, or `unknown`.
 319
 320 OWNER <``string``>::
 321 Owner of the file.
 322
 323 PACKET.IFACE <``string``>::
 324 Interface name associated with the packet socket.
 325
 326 PACKET.PROTOCOL <``string``>::
 327 L3 protocol associated with the packet socket.
 328
 329 PARTITION <``string``>::
 330 Block device name resolved by `/proc/partition`.
 331
 332 PID <``number``>::
 333 PID of the process opening the file.
 334
 335 PIDFD.COMM <``string``>::
 336 Command of the process targeted by the pidfd.
 337
 338 PIDFD.NSPID <``string``>::
 339 Value of NSpid field in ``/proc/``_pid_``/fdinfo/``_fd_ of the pidfd.
 340 +
 341 Quoted from kernel/fork.c of Linux source tree:
 342 +
 343 ____
 344 If pid namespaces are supported then this function will also print
 345 the pid of a given pidfd refers to for all descendant pid namespaces
 346 starting from the current pid namespace of the instance, i.e. the
 347 Pid field and the first entry in the NSpid field will be identical.
 348
 349 Note that this differs from the Pid and NSpid fields in
 350 /proc/<pid>/status where Pid and NSpid are always shown relative to
 351 the pid namespace of the procfs instance.
 352 ____
 353
 354 PIDFD.PID <``number``>::
 355 PID of the process targeted by the pidfd.
 356
 357 PING.ID <`number`>::
 358 ICMP echo request id used on the PING socket.
 359
 360 POS <``number``>::
 361 File position.
 362
 363 RAW.PROTOCOL <``number``>::
 364 Protocol number of the raw socket.
 365
 366 RDEV <``string``>::
 367 Device ID (if special file).
 368
 369 SIGNALFD.MASK <``string``>::
 370 Masked signals.
 371
 372 SIZE <``number``>::
 373 File size.
 374
 375 SOCK.LISTENING <``boolean``>::
 376 Listening socket.
 377
 378 SOCK.NETS <``number``>::
 379 Inode identifying network namespace where the socket belongs to.
 380
 381 SOCK.PROTONAME <``string``>::
 382 Protocol name.
 383
 384 SOCK.STATE <``string``>::
 385 State of socket.
 386
 387 SOCK.TYPE <``string``>::
 388 Type of socket. Here type means the second parameter of
 389 socket system call:
 390 +
 391 * stream
 392 * dgram
 393 * raw
 394 * rdm
 395 * seqpacket
 396 * dccp
 397 * packet
 398
 399 SOURCE <``string``>::
 400 File system, partition, or device containing the file.
 401
 402 STTYPE <``string``>::
 403 Raw file types returned from *stat*(2): BLK, CHR, DIR, FIFO, LINK, REG, SOCK, or UNKN.
 404
 405 TCP.LADDR <``string``>::
 406 Local L3 (INET.LADDR or INET6.LADDR) address and local TCP port.
 407
 408 TCP.LPORT <``number``>::
 409 Local TCP port.
 410
 411 TCP.RADDR <``string``>::
 412 Remote L3 (INET.RADDR or INET6.RADDR) address and remote TCP port.
 413
 414 TCP.RPORT <``number``>::
 415 Remote TCP port.
 416
 417 TID <``number``>::
 418 Thread ID of the process opening the file.
 419
 420 TIMERFD.CLOCKID <``string``>::
 421 Clockid.
 422
 423 TIMERFD.INTERVAL <``number``>::
 424 Interval.
 425
 426 TIMERFD.REMAINING <``number``>::
 427 Remaining time.
 428
 429 TYPE <``string``>::
 430 Cooked version of STTYPE. It is same as STTYPE with exceptions.
 431 For SOCK, print the value for SOCK.PROTONAME.
 432 For UNKN, print the value for AINODECLASS if SOURCE is anon_inodefs.
 433
 434 UDP.LADDR <``string``>::
 435 Local IP address and local UDP port.
 436
 437 UDP.LPORT <``number``>::
 438 Local UDP port.
 439
 440 UDP.RADDR <``string``>::
 441 Remote IP address and remote UDP port.
 442
 443 UDP.RPORT <``number``>::
 444 Remote UDP port.
 445
 446 UDPLITE.LADDR <``string``>::
 447 Local IP address and local UDPLite port.
 448
 449 UDPLITE.LPORT <``number``>::
 450 Local UDP port.
 451
 452 UDPLITE.RADDR <``string``>::
 453 Remote IP address and remote UDPLite port.
 454
 455 UDPLITE.RPORT <``number``>::
 456 Remote UDP port.
 457
 458 UID <``number``>::
 459 User ID number.
 460
 461 UNIX.PATH <``string``>::
 462 Filesystem pathname for UNIX domain socket.
 463
 464 USER <``string``>::
 465 User of the process.
 466
 467 == FILTER EXPRESSION
 468
 469 *lsfd* evaluates the expression passed to *--filter* option every time
 470 before printing a file line. *lsfd* prints the line only if the result
 471 of evaluation is `true`.
 472
 473 An expression consists of column names, literals and, operators like:
 474 `DELETED`, `(PID == 1)`, `(NAME == "/etc/passwd")`, `(PID == 1) && DELETED`.
 475 `DELETED`, `PID`, and `NAME` are column names in the example.
 476 `1` and "/etc/passwd" are literals.
 477 `==` and `&&` are operators.
 478
 479 Before evaluation, *lsfd* substitutes column names in the given
 480 expression with actual column values in the line. There are three
 481 different data types: `boolean`, `string`, and `number`.  For columns
 482 with a `boolean` type, the value can be stand-alone.  For `string` and
 483 `number` values, the value must be an operand of an operator, for
 484 example, `(PID == 1)`. See *OUTPUT COLUMNS* about the types of
 485 columns.
 486
 487 Literal is for representing a value directly. See BOOLLIT, STRLIT, and
 488 NUMLIT. Different data types have different literal syntax.
 489
 490 An operator works with one or two operand(s). An operator has an
 491 expectation about the data type(s) of its operands. Giving an
 492 unexpected data type to an operator causes a syntax error.
 493
 494 Operators taking two operands are `and`, `or`, `eq`, `ne`, `le`, `lt`, `ge`, `gt`, `=~`, `!~`.
 495 Alphabetically named operators have C-language
 496 flavored aliases: `&&`, `||`, `==`, `!=`, `<`, `<=`, `>=`, and `>`.
 497
 498 `!` is the only operator that takes one operand.
 499
 500 `eq`, `ne`, and their aliases expect operands have the same data type.
 501 Applying these operators return a `boolean`.
 502
 503 `and`, `or`, `not` and their aliases expect operands have `boolean` data
 504 type. Applying these operators return a `boolean`.
 505
 506 `lt`, `le`, `gt`, `ge`, and their aliases expect operands have
 507 `number` data types. Applying these operators return a `boolean`.
 508
 509 `=~` is for regular expression matching; if a string at the right side
 510 matches a regular expression at the left side, the result is true.
 511 The right side operand must be a string literal. See STRLIT about the
 512 syntax.
 513
 514 `!~` is a short-hand version of `not (STR =~ PAT)`; it inverts the
 515 result of `=~`.
 516
 517 === Limitations
 518
 519 The current implementation does not define precedences within
 520 operators.  Use `(` and `)` explicitly for grouping the
 521 sub-expressions if your expression uses more than two operators.
 522
 523 About `number` typed values, the filter engine supports only
 524 non-negative integers, and non-negative floating point numbers.
 525
 526 === Semi-formal syntax
 527
 528 //TRANSLATORS: In the following messages, translate only the <``variables``>.
 529 EXPR :: BOOLEXP
 530
 531 BOOLEXP0 :: COLUMN <``boolean``> | BOOLLIT | _(_ BOOLEXP _)_
 532
 533 BOOLEXP :: BOOLEXP0 | BOOLOP1 | BOOLOP2 | BOOLOP2BL | BOOLOP2CMP | BOOLOP2REG
 534
 535 COLUMN :: [\_A-Za-z][-_:A-Za-z0-9]*
 536
 537 BOOLOP1 :: _!_ BOOLEXP0 | _not_ BOOLEXP0
 538
 539 STREXP :: COLUMN <``string``> | STRLIT
 540
 541 NUMEXP :: COLUMN <``number``> | NUMLIT
 542
 543 BOOLLIT :: _true_ | _false_
 544
 545 CHARS  :: ( [^\] | _\\_ | _\'_ | _\"_ )*
 546
 547 STRLIT :: _'_ CHARS _'_ | _"_ CHARS _"_
 548
 549 NUMLIT :: INTLIT | FNUMLIT
 550
 551 INTLIT :: [1-9][0-9]* | _0_
 552
 553 FNUMLIT :: INTLIT _._ [0-9][0-9]*
 554
 555 BOOLOP2 :: STREXP OP2 STREXP | NUMEXP OP2 NUMEXP | BOOLEXP0 OP2 BOOLEXP0
 556
 557 OP2   :: _==_ | _eq_ | _!=_ | _ne_
 558
 559 BOOLOP2BL :: BOOLEXP0 OP2BL BOOLEXP0
 560
 561 OP2BL ::  _&&_ | _and_ |  _||_ | _or_
 562
 563 BOOLOP2CMP :: NUMEXP OP2CMP NUMEXP
 564
 565 OP2CMP :: _<_ | _lt_ | _\<=_ | _le_ | _>_ | _gt_ | _>=_ | _ge_
 566
 567 BOOLOP2REG :: STREXP OP2REG STRLIT
 568
 569 OP2REG :: _=~_ | _!~_
 570
 571 == FILTER EXAMPLES
 572
 573 *lsfd* has few options for filtering. In most of cases, what you should
 574 know is *-Q* (or *--filter*) option.  Combined with *-o* (or
 575 *--output*) option, you can customize the output as you want.
 576
 577 //TRANSLATORS: In the following messages, don't forget to add whitespace at the end!
 578 List files associated with PID 1 and PID 2 processes: ::
 579 ....
 580 # lsfd -Q '(PID == 1) or (PID == 2)'
 581 ....
 582
 583 Do the same in an alternative way: ::
 584 ....
 585 # lsfd -Q '(PID == 1) || (PID == 2)'
 586 ....
 587
 588 Do the same in a more efficient way: ::
 589 ....
 590 # lsfd --pid 1,2
 591 ....
 592
 593 Whitescapes can be used instead of a comma: ::
 594 ....
 595 # lsfd --pid '1 2'
 596 ....
 597
 598 Utilize *pidof*(1) for list the files associated with "firefox": ::
 599 ....
 600 # lsfd --pid "$(pidof firefox)"
 601 ....
 602
 603 List the 1st file descriptor opened by PID 1 process: ::
 604 ....
 605 # lsfd -Q '(PID == 1) and (FD == 1)'
 606 ....
 607
 608 Do the same in an alternative way: ::
 609 ....
 610 # lsfd -Q '(PID == 1) && (FD == 1)'
 611 ....
 612
 613 List all running executables: ::
 614 ....
 615 # lsfd -Q 'ASSOC == "exe"'
 616 ....
 617
 618 Do the same in an alternative way: ::
 619 ....
 620 # lsfd -Q 'ASSOC eq "exe"'
 621 ....
 622
 623 Do the same but print only file names: ::
 624 ....
 625 # lsfd -o NAME -Q 'ASSOC eq "exe"' | sort -u
 626 ....
 627
 628 List deleted files associated to processes: ::
 629 ....
 630 # lsfd -Q 'DELETED'
 631 ....
 632
 633 List non-regular files: ::
 634 ....
 635 # lsfd -Q 'TYPE != "REG"'
 636 ....
 637
 638 List block devices: ::
 639 ....
 640 # lsfd -Q 'DEVTYPE == "blk"'
 641 ....
 642
 643 Do the same with TYPE column: ::
 644 ....
 645 # lsfd -Q 'TYPE == "BLK"'
 646 ....
 647
 648 List files including "dconf" directory in their names: ::
 649 ....
 650 # lsfd -Q 'NAME =~ ".\*/dconf/.*"'
 651 ....
 652
 653 List files opened in a QEMU virtual machine: ::
 654 ....
 655 # lsfd -Q '(COMMAND =~ ".\*qemu.*") and (FD >= 0)'
 656 ....
 657
 658 Hide files associated to kernel threads: ::
 659 ....
 660 # lsfd -Q '!KTHREAD'
 661 ....
 662
 663 List timerfd files expired within 0.5 seconds: ::
 664 ....
 665 # lsfd -Q '(TIMERFD.remaining < 0.5) and (TIMERFD.remaining > 0.0)'
 666 ....
 667
 668 == COUNTER EXAMPLES
 669
 670 Report the numbers of netlink socket descriptors and unix socket descriptors: ::
 671 ....
 672 # lsfd --summary=only \
 673         -C 'netlink sockets':'(NAME =~ "NETLINK:.*")' \
 674         -C 'unix sockets':'(NAME =~ "UNIX:.*")'
 675 VALUE COUNTER
 676    57 netlink sockets
 677  1552 unix sockets
 678 ....
 679
 680 Do the same but print in JSON format: ::
 681 ....
 682 # lsfd --summary=only --json \
 683         -C 'netlink sockets':'(NAME =~ "NETLINK:.*")' \
 684         -C 'unix sockets':'(NAME =~ "UNIX:.*")'
 685 {
 686    "lsfd-summary": [
 687       {
 688          "value": 15,
 689          "counter": "netlink sockets"
 690       },{
 691          "value": 798,
 692          "counter": "unix sockets"
 693       }
 694    ]
 695 }
 696 ....
 697
 698
 699 == HISTORY
 700
 701 The *lsfd* command is part of the util-linux package since v2.38.
 702
 703 == AUTHORS
 704
 705 mailto:yamato@redhat.com[Masatake YAMATO],
 706 mailto:kzak@redhat.com[Karel Zak]
 707
 708 == SEE ALSO
 709
 710 *lsof*(8)
 711 *pidof*(1)
 712 *proc*(5)
 713 *socket*(2)
 714 *stat*(2)
 715
 716 include::man-common/bugreports.adoc[]
 717
 718 include::man-common/footer.adoc[]
 719
 720 ifdef::translation[]
 721 include::man-common/translation.adoc[]
 722 endif::[]