htop(1) Utils htop(1)
htop - interactive process viewer
This program is a free (GPL) ncurses-based process viewer.
It is similar to top, but allows to scroll the list vertically and horizontally to see all
processes and their full command lines.
Tasks related to processes (killing, renicing) can be done without entering their PIDs.
The following flags are supported:
Delay between updates, in tenths of seconds
Show only processes of a given user
Sort by this column (use --sort-key help for a column list)
The following commands are supported:
Arrows, PgUP, PgDn, Home, End
Scroll process list.
"Tag": mark a process. Commands that can operate on multiple processes, like "kill",
will then apply over the list of tagged processes, instead of the currently high-
U "Untag" all processes (remove all tags added with the Space key).
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.
Setup screen. There you can configure meters displayed on the top side of the screen,
as well as set various display options, choose among color schemes and select the
layout of the displayed columns.
Incremental process search: type in part of a process command line and the selection
highlight will be moved to it. While in search mode, pressing this key will cycle
through matching occurrences.
Invert sort order: if sort order is increasing, switch to decreasing, and vice-versa.
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.
Select field for sorting. The sort field is indicated by a highlight in the header.
F7, ], -
Increase selected process priority (subtract from 'nice' value). This can be done by
the superuser only.
F8, [, +
Decrease selected process priority (add to 'nice' value)
"Kill" process: sends a signal which is selected in a menu, to one or a group of pro-
cesses. If processes were tagged, sends the signal to all tagged processes. If none
is tagged, sends to the currently selected process.
+, - When in tree view mode, expand or collapse subtree. When a subtree is collapsed a "+"
sign shows to the left of the process name.
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.
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 always 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 ordinary processes
(such as recent NPTL-based systems), this can hide threads from userspace processes
in the process list. (This is a toggle key.)
Refresh: redraw screen and recalculate values.
PID search: type in process ID and the selection highlight will be moved to it.
htop is developed by Hisham Muhammad <email@example.com>.
This man page was written by Bartosz Fenski <firstname.lastname@example.org> for the Debian GNU/Linux distri-
bution (but it may be used by others), and updated by Hisham Muhammad.
Bartosz Fenski <email@example.com> 0.9 htop(1)