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HTOP(1) 			  User Commands 			 HTOP(1)

NAME
     htop, pcp-htop - interactive process viewer

SYNOPSIS
     htop [-dCFhpustvH]
     pcp-htop [-dCFhpustvH] [--host/-h host]

DESCRIPTION
     htop is a cross-platform ncurses-based process viewer.

     It is similar to top, but allows you to scroll vertically and horizontally,
     and  interact  using  a  pointing	device	(mouse).   You	can  observe all
     processes running on the system, along with their command	line  arguments,
     as well as view them in a tree format, select multiple processes and act on
     them all at once.

     Tasks related to processes (killing, renicing) can be done without entering
     their PIDs.

     pcp-htop  is  a  version of htop built using the Performance Co-Pilot (PCP)
     Metrics API (see PCPIntro(1), PMAPI(3)), allowing to extend htop to display
     values from arbitrary metrics.  See the section below titled  CONFIG  FILES
     for further details.

COMMAND-LINE OPTIONS
     Mandatory arguments to long options are mandatory for short options too.

     -d --delay=DELAY
	    Delay  between updates, in tenths of a second. If the delay value is
	    less than 1, it is increased to 1, i.e. 1/10 second.  If  the  delay
	    value is greater than 100, it is decreased to 100, i.e. 10 seconds.

     -C --no-color --no-colour
	    Start htop in monochrome mode

     -F --filter=FILTER
	    Filter  processes  by  terms  matching  the  commands. The terms are
	    matched case-insensitive and as fixed strings (not regexs). You  can
	    separate multiple terms with "|".

     -h --help
	    Display a help message and exit

     -p --pid=PID,PID...
	    Show only the given PIDs

     -s --sort-key COLUMN
	    Sort  by  this column (use --sort-key help for a column list).  This
	    will force a list view unless you  specify	-t  at	the  same  time.
	    Sorting in tree mode applies to the direct children of each process.

     -u --user[=USERNAME|UID]
	    Show only the processes of a given user, or self if omitted

     -U --no-unicode
	    Do not use unicode but ASCII characters for graph meters

     -M --no-mouse
	    Disable support of mouse control

     --readonly
	    Disable all system and process changing features

     -V --version
	    Output version information and exit

     -t --tree
	    Show  processes  in tree view. This can be used to force a tree view
	    when requesting a sort order with -s.

     -H --highlight-changes=DELAY
	    Highlight new and old processes

     --drop-capabilities[=off|basic|strict]
	    Linux only; this option needs to have been enabled	at  compile-time
	    and requires libcap support at runtime.
	    Drop  unneeded  Linux  capabilities.   In  strict mode features like
	    killing, changing process priorities and reading process  delay  ac-
	    counting  information  will not work due to fewer capabilities being
	    held.

INTERACTIVE COMMANDS
     The following commands are supported while in htop:

     Tab, Shift-Tab
	  Select the next / the previous screen tab to display.  You can  enable
	  showing the screen tab names in the Setup screen (F2).

     Up, Alt-k
	  Select  (highlight)  the  previous process in the process list. Scroll
	  the list if necessary.

     Down, Alt-j
	  Select (highlight) the next process in the process  list.  Scroll  the
	  list if necessary.

     Left, Alt-h
	  Scroll the process list left.

     Right, Alt-l
	  Scroll the process list right.

     PgUp, PgDn
	  Scroll the process list up or down one window.

     Home
	  Scroll to the top of the process list and select the first process.

     End  Scroll to the bottom of the process list and select the last process.

     Ctrl-A, ^
	  Scroll  left	to the beginning of the process entry (i.e. beginning of
	  line).

     Ctrl-E, $
	  Scroll right to the end of the process entry (i.e. end of line).

     Space
	  Tag or  untag  a  process.  Commands	that  can  operate  on	multiple
	  processes,  like  "kill",  will  then  apply	over  the list of tagged
	  processes, instead of the currently highlighted one.

     c	  Tag the current process and its children. Commands that can operate on
	  multiple processes, like "kill", will then  apply  over  the	list  of
	  tagged processes, instead of the currently highlighted one.

     U	  Untag all processes (remove all tags added with the Space or c keys).

     s	  Trace  process  system calls: if strace(1) is installed, pressing this
	  key will attach it to the currently  selected  process,  presenting  a
	  live update of system calls issued by the process.

     l	  Display  open  files	for a process: if lsof(1) is installed, pressing
	  this key will display the list  of  file  descriptors  opened  by  the
	  process.

     w	  Display the command line of the selected process in a separate screen,
	  wrapped onto multiple lines as needed.

     x	  Display  the	active	file locks of the selected process in a separate
	  screen.

     F1, h, ?
	  Go to the help screen

     F2, S
	  Go to the setup screen, where you can configure the  meters  displayed
	  at  the  top	of the screen, set various display options, choose among
	  color schemes, and select which columns are displayed, in which order.

     F3, /
	  Incrementally search the command lines of all the displayed processes.
	  The currently selected (highlighted) command will update as you  type.
	  While  in  search mode, pressing F3 will cycle through matching occur-
	  rences.  Pressing Shift-F3 will cycle backwards.

	  Alternatively the search can be started by simply typing  the  command
	  you are looking for, although for the first character normal key bind-
	  ings take precedence.

     F4, \
	  Incremental  process filtering: type in part of a process command line
	  and only processes whose names match will be shown. To cancel  filter-
	  ing,	enter  the  Filter  option again and press Esc.  The matching is
	  done case-insensitive. Terms are fixed strings (no  regex).	You  can
	  separate multiple terms with "|".

     F5, t
	  Tree	view: organize processes by parenthood, and layout the relations
	  between them as a tree. Toggling the key will switch between tree  and
	  your	previously  selected  sort view. Selecting a sort view will exit
	  tree view.

     F6, <, >
	  Selects a field for sorting, also accessible through	<  and	>.   The
	  current sort field is indicated by a highlight in the header.

     F7, ]
	  Increase the selected process's priority (subtract from 'nice' value).
	  This can only be done by the superuser.

     F8, [
	  Decrease the selected process's priority (add to 'nice' value)

     Shift-F7, }
	  Increase  the selected process's autogroup priority (subtract from au-
	  togroup 'nice' value).  This can only be done by the superuser.

     Shift-F8, {
	  Decrease the selected process's autogroup priority (add  to  autogroup
	  'nice' value)

     F9, k
	  "Kill"  process: sends a signal which is selected in a menu, to one or
	  a group of processes. If processes were tagged, sends  the  signal  to
	  all  tagged  processes.  If none is tagged, sends to the currently se-
	  lected process.

     F10, q
	  Quit

     I	  Invert the sort order: if sort order is increasing, switch to decreas-
	  ing, and vice-versa.

     +, -, *
	  When in tree view mode, expand or collapse subtree. When a subtree  is
	  collapsed  a "+" sign shows to the left of the process name.	Pressing
	  "*" will expand or collapse all children of PIDs without  parents,  so
	  typically PID 1 (init) and PID 2 (kthreadd on Linux, if kernel threads
	  are shown).

     a (on multiprocessor machines)
	  Set CPU affinity: mark which CPUs a process is allowed to use.

     u	  Show only processes owned by a specified user.

     N	  Sort by PID.

     M	  Sort by memory usage (top compatibility key).

     P	  Sort by processor usage (top compatibility key).

     T	  Sort by time (top compatibility key).

     F	  "Follow"  process:  if  the  sort  order causes the currently selected
	  process to move in the list, make the selection bar follow it. This is
	  useful for monitoring a process: this way, you can keep a process  al-
	  ways	visible  on  screen. When a movement key is used, "follow" loses
	  effect.

     K	  Hide kernel threads: prevent the threads belonging the  kernel  to  be
	  displayed in the process list. (This is a toggle key.)

     H	  Hide user threads: on systems that represent them differently than or-
	  dinary  processes  (such  as recent NPTL-based systems), this can hide
	  threads from userspace processes in the process list. (This is a  tog-
	  gle key.)

     O	  Hide containerized processes: prevent processes running in a container
	  from being displayed in the process list. (This is a toggle key.)

     p	  Show full paths to running programs, where applicable. (This is a tog-
	  gle key.)

     Z	  Pause/resume process updates.

     m	  Merge exe, comm and cmdline, where applicable. (This is a toggle key.)

     Ctrl-L
	  Refresh: redraw screen and recalculate values.

     Numbers
	  PID  search:	type  in  process ID and the selection highlight will be
	  moved to it.

COLUMNS
     The following columns can display data about each process. A value  of  '-'
     in  all  the rows indicates that a column is unsupported on your system, or
     currently unimplemented in htop.  The names below are the ones used in  the
     "Available  Columns"  section  of	the setup screen. If a different name is
     shown in htop's main screen, it is shown below in parenthesis.

     Command
	  The full command line of the process	(i.e.  program	name  and  argu-
	  ments).

	  If the option 'Merge exe, comm and cmdline in Command' (toggled by the
	  'm' key) is active, the executable path (/proc/[pid]/exe) and the com-
	  mand	name  (/proc/[pid]/comm)  are also shown merged with the command
	  line, if available.

	  The program basename is highlighted if set in the configuration. Addi-
	  tional highlighting can be configured for stale executables  (cf.  EXE
	  column below).

	  The Command column should be the last column in each screen as can get
	  very	long  and  profits  from being able to extend its length dynami-
	  cally.

     COMM
	  The command name of the process  obtained  from  /proc/[pid]/comm,  if
	  readable.

	  Requires Linux kernel 2.6.33 or newer.

     EXE  The  abbreviated  basename  of the executable of the process, obtained
	  from /proc/[pid]/exe, if readable. htop is able to read this	file  on
	  linux   for	ALL   the  processes  only  if	it  has  the  capability
	  CAP_SYS_PTRACE or root privileges.

	  The basename is marked in red  if  the  executable  used  to	run  the
	  process  has	been  replaced	or  deleted  on  disk  since the process
	  started. The information is obtained by  processing  the  contents  of
	  /proc/[pid]/exe.

	  Furthermore  the  basename  is  marked in yellow if any library is re-
	  ported as having been replaced or deleted on disk since  it  was  last
	  loaded.  The	information  is  obtained  by processing the contents of
	  /proc/[pid]/maps.

	  When deciding the color the replacement of the main executable  always
	  takes  precedence  over  replacement of any other library. If only the
	  memory map indicates a replacement of the main executable,  this  will
	  show as if any other library had been replaced or deleted.

	  This	additional  color  markup  can be configured in the "Display Op-
	  tions" section of the setup screen.

	  Displaying EXE requires CAP_SYS_PTRACE and PTRACE_MODE_READ_FSCRED.

     PID  The process ID.

     STATE (S)
	  The state of the process:
	     S for sleeping
	     I for idle (longer inactivity than sleeping on platforms that  dis-
	  tinguish)
	     R for running
	     D for disk sleep (uninterruptible)
	     Z for zombie (waiting for parent to read its exit status)
	     T for traced or suspended (e.g by SIGTSTP)
	     W for paging

     PPID
	  The parent process ID.

     PGRP
	  The process's group ID.

     SESSION (SID)
	  The process's session ID.

     TTY  The controlling terminal of the process.

     TPGID
	  The process ID of the foreground process group of the controlling ter-
	  minal.

     MINFLT
	  The number of page faults happening in the main memory.

     CMINFLT
	  The  number of minor faults for the process's waited-for children (see
	  MINFLT above).

     MAJFLT
	  The number of page faults happening out of the main memory.

     CMAJFLT
	  The number of major faults for the process's waited-for children  (see
	  MAJFLT above).

     UTIME (UTIME+)
	  The  user  CPU time, which is the amount of time the process has spent
	  executing on the CPU in user mode (i.e. everything but system  calls),
	  measured in clock ticks.

     STIME (STIME+)
	  The  system CPU time, which is the amount of time the kernel has spent
	  executing system calls on behalf of the  process,  measured  in  clock
	  ticks.

     CUTIME (CUTIME+)
	  The  children's  user  CPU  time,  which  is	the  amount  of time the
	  process's waited-for children have spent executing in user  mode  (see
	  UTIME above).

     CSTIME (CSTIME+)
	  The children's system CPU time, which is the amount of time the kernel
	  has  spent  executing  system  calls	on  behalf  of all the process's
	  waited-for children (see STIME above).

     PRIORITY (PRI)
	  The kernel's internal priority for the process, usually just its  nice
	  value plus twenty. Different for real-time processes.

     NICE (NI)
	  The  nice value of a process, from 19 (low priority) to -20 (high pri-
	  ority). A high value means the process is being nice,  letting  others
	  have	a higher relative priority. The usual OS permission restrictions
	  for adjusting priority apply.

     STARTTIME (START)
	  The time the process was started.

     PROCESSOR (CPU)
	  The ID of the CPU the process last executed on.

     M_VIRT (VIRT)
	  The size of the virtual memory of the process.

     M_RESIDENT (RES)
	  The resident set size (text + data + stack) of the process  (i.e.  the
	  size of the process's used physical memory).

     M_SHARE (SHR)
	  The size of the process's shared pages.

     M_TRS (CODE)
	  The  text  resident  set  size  of  the  process (i.e. the size of the
	  process's executable instructions).

     M_DRS (DATA)
	  The data resident set size (data + stack) of	the  process  (i.e.  the
	  size of anything except the process's executable instructions).

     M_LRS (LIB)
	  The library size of the process.

     M_SWAP (SWAP)
	  The size of the process's swapped pages.

     M_PSS (PSS)
	  The proportional set size, same as M_RESIDENT but each page is divided
	  by the number of processes sharing it.

     M_M_PSSWP (PSSWP)
	  The  proportional  swap share of this mapping, unlike M_SWAP this does
	  not take into account swapped out page of underlying shmem objects.

     ST_UID (UID)
	  The user ID of the process owner.

     PERCENT_CPU (CPU%)
	  The percentage of the CPU time that the process  is  currently  using.
	  This	is the default way to represent CPU usage in Linux. Each process
	  can consume up to 100% which means the full capacity of the core it is
	  running on. This is sometimes called "Irix mode" e.g. in top(1).

     PERCENT_NORM_CPU (NCPU%)
	  The percentage of the CPU time that the  process  is	currently  using
	  normalized  by CPU count. This is sometimes called "Solaris mode" e.g.
	  in top(1).

     PERCENT_MEM (MEM%)
	  The percentage of memory the process is currently using (based on  the
	  process's resident memory size, see M_RESIDENT above).

     USER
	  The username of the process owner, or the user ID if the name can't be
	  determined.

	  On Linux the username is highlighted if the process has elevated priv-
	  ileges,  i.e. if it has been started from binaries with file capabili-
	  ties set or retained Linux capabilities, via the  ambient  set,  after
	  switching from the root user.

     TIME (TIME+)
	  The  time,  measured in clock ticks that the process has spent in user
	  and system time (see UTIME, STIME above).

     NLWP
	  The number of Light-Weight Processes (=threads) in the process.

     TGID
	  The thread group ID.

     CTID
	  OpenVZ container ID, a.k.a virtual environment ID.

     VPID
	  OpenVZ process ID.

     VXID
	  VServer process ID.

     RCHAR (RD_CHAR)
	  The number of bytes the process has read.

     WCHAR (WR_CHAR)
	  The number of bytes the process has written.

     SYSCR (RD_SYSC)
	  The number of read(2) syscalls for the process.

     SYSCW (WR_SYSC)
	  The number of write(2) syscalls for the process.

     RBYTES (IO_RBYTES)
	  Bytes of read(2) I/O for the process.

     WBYTES (IO_WBYTES)
	  Bytes of write(2) I/O for the process.

     CNCLWB (IO_CANCEL)
	  Bytes of cancelled write(2) I/O.

     IO_READ_RATE (DISK READ)
	  The I/O rate of read(2) in bytes per second, for the process.

     IO_WRITE_RATE (DISK WRITE)
	  The I/O rate of write(2) in bytes per second, for the process.

     IO_RATE (DISK R/W)
	  The I/O rate, IO_READ_RATE + IO_WRITE_RATE (see above).

     CGROUP
	  Which cgroup the process is in. For a shortened view see  the  CCGROUP
	  column below.

     CCGROUP
	  Shortened  view  of the cgroup name that the process is in.  This per-
	  forms some pattern-based replacements to shorten the displayed  string
	  and thus condense the information.
	     /*.slice is shortened to /[*] (exceptions below)
	     /system.slice is shortened to /[S]
	     /user.slice is shortened to /[U]
	     /user-*.slice  is	shortened to /[U:*] (directly preceding /[U] be-
	  fore dropped)
	     /machine.slice is shortened to /[M]
	     /machine-*.scope is shortened to /[SNC:*] (SNC: systemd nspawn con-
	  tainer), uppercase for the monitor
	     /lxc.monitor.* is shortened to /[LXC:*]
	     /lxc.payload.* is shortened to /[lxc:*]
	     /*.scope is shortened to /!*
	     /*.service is shortened to /* (suffix removed)

	  Encountered escape sequences (e.g. from  systemd)  inside  the  cgroup
	  name are not decoded.

     OOM  OOM killer score.

     CTXT
	  Incremental sum of voluntary and nonvoluntary context switches.

     IO_PRIORITY (IO)
	  The  I/O  scheduling	class followed by the priority if the class sup-
	  ports it:
	     R for Realtime
	     B for Best-effort
	     id for Idle

     PERCENT_CPU_DELAY (CPUD%)
	  The percentage of time spent waiting for a CPU (while  runnable).  Re-
	  quires CAP_NET_ADMIN.

     PERCENT_IO_DELAY (IOD%)
	  The percentage of time spent waiting for the completion of synchronous
	  block I/O. Requires CAP_NET_ADMIN.

     PERCENT_SWAP_DELAY (SWAPD%)
	  The  percentage  of time spent swapping in pages. Requires CAP_NET_AD-
	  MIN.

     AGRP
	  The autogroup identifier for the process. Requires Linux CFS to be en-
	  abled.

     ANI  The autogroup nice value for the process autogroup. Requires Linux CFS
	  to be enabled.

     All other flags
	  Currently unsupported (always displays '-').

EXTERNAL LIBRARIES
     While htop depends on most of the libraries it uses at build time there are
     two noteworthy exceptions to this rule. These  exceptions	both  relate  to
     data  displayed  in  meters displayed in the header of htop and were inten-
     tionally created as optional runtime dependencies	instead.   These  excep-
     tions are described below:

     libsystemd
	    The  bindings for libsystemd are used in the SystemD meter to deter-
	    mine the number of active services and  the  overall  system  state.
	    Looking  for the functions to determine these information at runtime
	    allows for builds to support these meters without forcing the  pack-
	    age  manager  to  install  these libraries on systems that otherwise
	    don't use systemd.

	    Summary: no build time dependency, optional  runtime  dependency  on
	    libsystemd via dynamic loading, with systemctl(1) fallback.

     libsensors
	    The  bindings  for libsensors are used for the CPU temperature read-
	    ings in the CPU usage meters if displaying the  temperature  is  en-
	    abled through the setup screen. In order for htop to show these tem-
	    peratures  correctly  though,  a  proper configuration of libsensors
	    through its usual configuration files is assumed and  that	all  CPU
	    cores  correspond  to  temperature	sensors from the coretemp driver
	    with core 0 corresponding to a sensor labelled "Core 0". The package
	    temperature may be given as "Package id 0". If  missing  it  is  in-
	    ferred as the maximum value from the available per-core readings.

	    Summary:  build time dependency on libsensors(3) C header files, op-
	    tional runtime dependency on libsensors(3) via dynamic loading.

CONFIG FILES
     By default htop reads its configuration from the XDG-compliant path ~/.con-
     fig/htop/htoprc.  The configuration file is overwritten upon clean exit  by
     htop's in-program Setup configuration, so it should not be hand-edited.  If
     no  user configuration exists htop tries to read the system-wide configura-
     tion from ${prefix}/etc/htoprc and as a last resort, falls back to its hard
     coded defaults.

     You may override the location of the configuration file using  the  $HTOPRC
     environment variable (so you can have multiple configurations for different
     machines that share the same home directory, for example).

     The  pcp-htop  utility makes use of htoprc in a similar way.  However, pcp-
     htop reads its configuration from a path more conventionally used	by  Per-
     formance  Co-Pilot  tools, ~/.pcp/htop/htoprc, in order to provide separate
     configuration when both htop and pcp-htop are installed and in  use.   pcp-
     htop  supports  additional configuration files below the same directory al-
     lowing new meters, columns and screen tabs to be added via the Setup screen
     (F2).  This displays additional  Available  Meters,  Available  Column  and
     Screen Tabs for each meter, column or screen configuration file.

     These pcp-htop configuration files are read once at startup.  The format of
     these files is described in detail in the pcp-htop(5) manual page.

     This  functionality  makes available many thousands of Performance Co-Pilot
     metrics for display by pcp-htop, as well as the ability to  display  custom
     metrics  added at individual sites.  Applications and services instrumented
     using the OpenMetrics format https://openmetrics.io can also  be  displayed
     by pcp-htop if the pmdaopenmetrics(1) component is configured.

     The  configuration  for  both  htop and pcp-htop is only saved when a clean
     exit is performed. Sending any signal will cause all configuration  changes
     to be lost.

MEMORY SIZES
     Memory  sizes  in	htop  are displayed in a human-readable form.  Sizes are
     printed in powers of 1024 using binary IEC units.	If no  suffix  is  shown
     the units are implicitly K as in KiB (kibibyte, 1 KiB = 1024 bytes).

     The  decision  to	use this convention was made in order to conserve screen
     space and make memory size representations consistent  throughout	htop  as
     allocations are granular to full memory pages (4 KiB for most platforms).

SEE ALSO
     proc(5), top(1), free(1), ps(1), uptime(1) and limits.conf(5).

SEE ALSO FOR PCP
     pmdaopenmetrics(1), PCPIntro(1), PMAPI(3), and pcp-htop(5).

AUTHORS
     htop  was	originally  developed  by Hisham Muhammad.  Nowadays it is main-
     tained by the community at <htop@groups.io>.

     pcp-htop is maintained as a collaboration between the <htop@groups.io>  and
     <pcp@groups.io>  communities,  and  forms	part of the Performance Co-Pilot
     suite of tools.

COPYRIGHT
     Copyright (C) 2004-2019 Hisham Muhammad.
     Copyright (C) 2020-2025 htop dev team.

     License GPLv2+: GNU General Public License version 2 or,  at  your  option,
     any later version.

     This  is  free software: you are free to change and redistribute it.  There
     is NO WARRANTY, to the extent permitted by law.

htop 3.4.1			      2025				 HTOP(1)

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