1HTOP(1) User Commands HTOP(1)
2
6 htop - interactive process viewer
7
9 htop [-dCFhpustvH]
10
12 htop is a cross-platform ncurses-based process viewer.
13 It is similar to top, but allows you to scroll vertically and horizon‐
15 tally, and interact using a pointing device (mouse). You can observe
16 all processes running on the system, along with their command line
17 arguments, as well as view them in a tree format, select multiple pro‐
18 cesses and acting on them all at once.
19 Tasks related to processes (killing, renicing) can be done without
21 entering their PIDs.
22
24 Mandatory arguments to long options are mandatory for short options
25 too.
26 -d --delay=DELAY
28 Delay between updates, in tenths of seconds. If the delay value
29 is less than 1 it is increased to 1, i.e. 1/10 second. If the
30 delay value is greater than 100, it is decreased to 100, i.e. 10
31 seconds.
32 -C --no-color --no-colour
34 Start htop in monochrome mode
35 -F --filter=FILTER
37 Filter processes by command
38 -h --help
40 Display a help message and exit
41 -p --pid=PID,PID...
43 Show only the given PIDs
44 -s --sort-key COLUMN
46 Sort by this column (use --sort-key help for a column list).
47 This will force a list view unless you specify -t at the same
48 time.
49 -u --user=USERNAME
51 Show only the processes of a given user
52 -U --no-unicode
54 Do not use unicode but ASCII characters for graph meters
55 -M --no-mouse
57 Disable support of mouse control
58 -V --version
60 Output version information and exit
61 -t --tree
63 Show processes in tree view. This can be used to force a tree
64 view when requesting a sort order with -s.
65 -H --highlight-changes=DELAY
67 Highlight new and old processes
68
70 The following commands are supported while in htop:
71 Up, Alt-k
73 Select (highlight) the previous process in the process list.
74 Scroll the list if necessary.
75 Down, Alt-j
77 Select (highlight) the next process in the process list. Scroll
78 the list if necessary.
79 Left, Alt-h
81 Scroll the process list left.
82 Right, Alt-l
84 Scroll the process list right.
85 PgUp, PgDn
87 Scroll the process list up or down one window.
88 Home Scroll to the top of the process list and select the first
90 process.
91 End Scroll to the bottom of the process list and select the last
93 process.
94 Ctrl-A, ^
96 Scroll left to the beginning of the process entry (i.e. beginning
97 of line).
98 Ctrl-E, $
100 Scroll right to the end of the process entry (i.e. end of line).
101 Space
103 Tag or untag a process. Commands that can operate on multiple pro‐
104 cesses, like "kill", will then apply over the list of tagged pro‐
105 cesses, instead of the currently highlighted one.
106 c Tag the current process and its children. Commands that can oper‐
108 ate on multiple processes, like "kill", will then apply over the
109 list of tagged processes, instead of the currently highlighted
110 one.
111 U Untag all processes (remove all tags added with the Space or c
113 keys).
114 s Trace process system calls: if strace(1) is installed, pressing
116 this key will attach it to the currently selected process, pre‐
117 senting a live update of system calls issued by the process.
118 l Display open files for a process: if lsof(1) is installed, press‐
120 ing this key will display the list of file descriptors opened by
121 the process.
122 w Display the command line of the selected process in a separate
124 screen, wrapped onto multiple lines as needed.
125 x Display the active file locks of the selected process in a sepa‐
127 rate screen.
128 F1, h, ?
130 Go to the help screen
131 F2, S
133 Go to the setup screen, where you can configure the meters dis‐
134 played at the top of the screen, set various display options,
135 choose among color schemes, and select which columns are dis‐
136 played, in which order.
137 F3, /
139 Incrementally search the command lines of all the displayed pro‐
140 cesses. The currently selected (highlighted) command will update
141 as you type. While in search mode, pressing F3 will cycle through
142 matching occurrences. Pressing Shift-F3 will cycle backwards.
143 Alternatively the search can be started by simply typing the com‐
145 mand you are looking for, although for the first character normal
146 key bindings take precedence.
147 F4, \
149 Incremental process filtering: type in part of a process command
150 line and only processes whose names match will be shown. To cancel
151 filtering, enter the Filter option again and press Esc.
152 F5, t
154 Tree view: organize processes by parenthood, and layout the rela‐
155 tions between them as a tree. Toggling the key will switch between
156 tree and your previously selected sort view. Selecting a sort view
157 will exit tree view.
158 F6, <, >
160 Selects a field for sorting, also accessible through < and >. The
161 current sort field is indicated by a highlight in the header.
162 F7, ]
164 Increase the selected process's priority (subtract from 'nice'
165 value). This can only be done by the superuser.
166 F8, [
168 Decrease the selected process's priority (add to 'nice' value)
169 F9, k
171 "Kill" process: sends a signal which is selected in a menu, to one
172 or a group of processes. If processes were tagged, sends the sig‐
173 nal to all tagged processes. If none is tagged, sends to the cur‐
174 rently selected process.
175 F10, q
177 Quit
178 I Invert the sort order: if sort order is increasing, switch to
180 decreasing, and vice-versa.
181 +, - When in tree view mode, expand or collapse subtree. When a subtree
183 is collapsed a "+" sign shows to the left of the process name.
184 a (on multiprocessor machines)
186 Set CPU affinity: mark which CPUs a process is allowed to use.
187 u Show only processes owned by a specified user.
189 N Sort by PID.
191 M Sort by memory usage (top compatibility key).
193 P Sort by processor usage (top compatibility key).
195 T Sort by time (top compatibility key).
197 F "Follow" process: if the sort order causes the currently selected
199 process to move in the list, make the selection bar follow it.
200 This is useful for monitoring a process: this way, you can keep a
201 process always visible on screen. When a movement key is used,
202 "follow" loses effect.
203 K Hide kernel threads: prevent the threads belonging the kernel to
205 be displayed in the process list. (This is a toggle key.)
206 H Hide user threads: on systems that represent them differently than
208 ordinary processes (such as recent NPTL-based systems), this can
209 hide threads from userspace processes in the process list. (This
210 is a toggle key.)
211 p Show full paths to running programs, where applicable. (This is a
213 toggle key.)
214 Z Pause/resume process updates.
216 m Merge exe, comm and cmdline, where applicable. (This is a toggle
218 key.)
219 Ctrl-L
221 Refresh: redraw screen and recalculate values.
222 Numbers
224 PID search: type in process ID and the selection highlight will be
225 moved to it.
226
228 The following columns can display data about each process. A value of
229 '-' in all the rows indicates that a column is unsupported on your sys‐
230 tem, or currently unimplemented in htop. The names below are the ones
231 used in the "Available Columns" section of the setup screen. If a dif‐
232 ferent name is shown in htop's main screen, it is shown below in paren‐
233 thesis.
234 Command
236 The full command line of the process (i.e. program name and argu‐
237 ments). If the option 'Merge exe, comm and cmdline in Command'
238 (toggled by the 'm' key) is set, and if readable, the executable
239 path (/proc/[pid]/exe) and the command name (/proc/[pid]/comm) are
240 also shown merged with the command line.
241 Comm The command name of the process obtained from /proc/[pid]/comm, if
243 readable.
244 Exe The abbreviated basename of the executable of the process,
246 obtained from /proc/[pid]/exe, if readable. htop is able to read
247 this file on linux for ALL the processes only if it has the capa‐
248 bility CAP_SYS_PTRACE or root privileges.
249 PID The process ID.
251 STATE (S)
253 The state of the process:
254 S for sleeping (idle)
255 R for running
256 D for disk sleep (uninterruptible)
257 Z for zombie (waiting for parent to read its exit status)
258 T for traced or suspended (e.g by SIGTSTP)
259 W for paging
260 PPID The parent process ID.
262 PGRP The process's group ID.
264 SESSION (SID)
266 The process's session ID.
267 TTY_NR (TTY)
269 The controlling terminal of the process.
270 TPGID
272 The process ID of the foreground process group of the controlling
273 terminal.
274 MINFLT
276 The number of page faults happening in the main memory.
277 CMINFLT
279 The number of minor faults for the process's waited-for children
280 (see MINFLT above).
281 MAJFLT
283 The number of page faults happening out of the main memory.
284 CMAJFLT
286 The number of major faults for the process's waited-for children
287 (see MAJFLT above).
288 UTIME (UTIME+)
290 The user CPU time, which is the amount of time the process has
291 spent executing on the CPU in user mode (i.e. everything but sys‐
292 tem calls), measured in clock ticks.
293 STIME (STIME+)
295 The system CPU time, which is the amount of time the kernel has
296 spent executing system calls on behalf of the process, measured in
297 clock ticks.
298 CUTIME (CUTIME+)
300 The children's user CPU time, which is the amount of time the
301 process's waited-for children have spent executing in user mode
302 (see UTIME above).
303 CSTIME (CSTIME+)
305 The children's system CPU time, which is the amount of time the
306 kernel has spent executing system calls on behalf of all the
307 process's waited-for children (see STIME above).
308 PRIORITY (PRI)
310 The kernel's internal priority for the process, usually just its
311 nice value plus twenty. Different for real-time processes.
312 NICE (NI)
314 The nice value of a process, from 19 (low priority) to -20 (high
315 priority). A high value means the process is being nice, letting
316 others have a higher relative priority. The usual OS permission
317 restrictions for adjusting priority apply.
318 STARTTIME (START)
320 The time the process was started.
321 PROCESSOR (CPU)
323 The ID of the CPU the process last executed on.
324 M_VIRT (VIRT)
326 The size of the virtual memory of the process.
327 M_RESIDENT (RES)
329 The resident set size (text + data + stack) of the process (i.e.
330 the size of the process's used physical memory).
331 M_SHARE (SHR)
333 The size of the process's shared pages.
334 M_TRS (CODE)
336 The text resident set size of the process (i.e. the size of the
337 process's executable instructions).
338 M_DRS (DATA)
340 The data resident set size (data + stack) of the process (i.e. the
341 size of anything except the process's executable instructions).
342 M_LRS (LIB)
344 The library size of the process.
345 M_DT (DIRTY)
347 The size of the dirty pages of the process.
348 M_SWAP (SWAP)
350 The size of the process's swapped pages.
351 M_PSS (PSS)
353 The proportional set size, same as M_RESIDENT but each page is
354 divided by the number of processes sharing it.
355 M_M_PSSWP (PSSWP)
357 The proportional swap share of this mapping, unlike M_SWAP this
358 does not take into account swapped out page of underlying shmem
359 objects.
360 ST_UID (UID)
362 The user ID of the process owner.
363 PERCENT_CPU (CPU%)
365 The percentage of the CPU time that the process is currently
366 using.
367 PERCENT_MEM (MEM%)
369 The percentage of memory the process is currently using (based on
370 the process's resident memory size, see M_RESIDENT above).
371 USER The username of the process owner, or the user ID if the name
373 can't be determined.
374 TIME (TIME+)
376 The time, measured in clock ticks that the process has spent in
377 user and system time (see UTIME, STIME above).
378 NLWP The number of threads in the process.
380 TGID The thread group ID.
382 CTID OpenVZ container ID, a.k.a virtual environment ID.
384 VPID OpenVZ process ID.
386 VXID VServer process ID.
388 RCHAR (RD_CHAR)
390 The number of bytes the process has read.
391 WCHAR (WR_CHAR)
393 The number of bytes the process has written.
394 SYSCR (RD_SYSC)
396 The number of read(2) syscalls for the process.
397 SYSCW (WR_SYSC)
399 The number of write(2) syscalls for the process.
400 RBYTES (IO_RBYTES)
402 Bytes of read(2) I/O for the process.
403 WBYTES (IO_WBYTES)
405 Bytes of write(2) I/O for the process.
406 CNCLWB (IO_CANCEL)
408 Bytes of cancelled write(2) I/O.
409 IO_READ_RATE (DISK READ)
411 The I/O rate of read(2) in bytes per second, for the process.
412 IO_WRITE_RATE (DISK WRITE)
414 The I/O rate of write(2) in bytes per second, for the process.
415 IO_RATE (DISK R/W)
417 The I/O rate, IO_READ_RATE + IO_WRITE_RATE (see above).
418 CGROUP
420 Which cgroup the process is in.
421 OOM OOM killer score.
423 CTXT Incremental sum of voluntary and nonvoluntary context switches.
425 IO_PRIORITY (IO)
427 The I/O scheduling class followed by the priority if the class
428 supports it:
429 R for Realtime
430 B for Best-effort
431 id for Idle
432 PERCENT_CPU_DELAY (CPUD%)
434 The percentage of time spent waiting for a CPU (while runnable).
435 Requires CAP_NET_ADMIN.
436 PERCENT_IO_DELAY (IOD%)
438 The percentage of time spent waiting for the completion of syn‐
439 chronous block I/O. Requires CAP_NET_ADMIN.
440 PERCENT_SWAP_DELAY (SWAPD%)
442 The percentage of time spent swapping in pages. Requires
443 CAP_NET_ADMIN.
444 COMM The command name for the process. Requires Linux kernel 2.6.33 or
446 newer.
447 EXE The executable file of the process as reported by the kernel.
449 Requires CAP_SYS_PTRACE and PTRACE_MODE_READ_FSCRED.
450 All other flags
452 Currently unsupported (always displays '-').
453
455 While htop depends on most of the libraries it uses at build time there
456 are two noteworthy exceptions to this rule. These exceptions both
457 relate to data displayed in meters displayed in the header of htop and
458 were intentionally created as optional runtime dependencies instead.
459 These exceptions are described below:
460 libsystemd
462 The bindings for libsystemd are used in the SystemD meter to
463 determine the number of active services and the overall system
464 state. Looking for the functions to determine these information
465 at runtime allows for builds to support these meters without
466 forcing the package manager to install these libraries on sys‐
467 tems that otherwise don't use systemd.
468 Summary: no build time dependency, optional runtime dependency
470 on libsystemd via dynamic loading, with systemctl(1) fallback.
471 libsensors
473 The bindings for libsensors are used for the CPU temperature
474 readings in the CPU usage meters if displaying the temperature
475 is enabled through the setup screen. In order for htop to show
476 these temperatures correctly though, a proper configuration of
477 libsensors through its usual configuration files is assumed and
478 that all CPU cores correspond to temperature sensors from the
479 coretemp driver with core 0 corresponding to a sensor labelled
480 "Core 0". The package temperature may be given as "Package id
481 0". If missing it is inferred as the maximum value from the
482 available per-core readings.
483 Summary: build time dependency on libsensors(3) C header files,
485 optional runtime dependency on libsensors(3) via dynamic load‐
486 ing.
487
489 By default htop reads its configuration from the XDG-compliant path
490 ~/.config/htop/htoprc. The configuration file is overwritten by htop's
491 in-program Setup configuration, so it should not be hand-edited. If no
492 user configuration exists htop tries to read the system-wide configura‐
493 tion from /etc/htoprc and as a last resort, falls back to its hard
494 coded defaults.
495 You may override the location of the configuration file using the $HTO‐
497 PRC environment variable (so you can have multiple configurations for
498 different machines that share the same home directory, for example).
499
501 Memory sizes in htop are displayed in a human-readable form. Sizes are
502 printed in powers of 1024. (e.g., 1023M = 1072693248 Bytes)
503 The decision to use this convention was made in order to conserve
505 screen space and make memory size representations consistent throughout
506 htop.
507
509 proc(5), top(1), free(1), ps(1), uptime(1) and limits.conf(5).
510
512 htop was originally developed by Hisham Muhammad. Nowadays it is main‐
513 tained by the community at <htop@groups.io>.
514htop 3.0.5 2020 HTOP(1)