Ubuntu Manpage: htop - interactive process viewer

NAME

       htop - interactive process viewer

SYNOPSIS

       htop [-dChusv]

DESCRIPTION

       Htop is a free (GPL) ncurses-based process viewer for Linux.

       It  is  similar  to  top,  but  allows  you to scroll vertically and horizontally, so you can see all the
       processes running on the system, along with their full command lines.

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

COMMAND-LINE OPTIONS

       Mandatory arguments to long options are madatory for short options too.

       -d --delay=DELAY
              Delay between updates, in tenths of seconds

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

       -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)

       -u --user=USERNAME
              Show only the processes of a given user

       -v --version
              Output version information and exit

INTERACTIVE COMMANDS

The following commands are supported while in htop:

Arrows, PgUP, PgDn, Home, End
Scroll the process list.

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.

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.

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

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 occurrences.

F4, \
Incremental process filtering: type in part of a process command line and only processes whose names
match will be shown. To cancel filtering, enter the Filter option again and press Esc.

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, <, >
Select a field for sorting. 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)

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 selected process.

F10, q
Quit

I Invert the sort order: if sort order is increasing, switch to decreasing, 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.

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.)

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 arguments).

       PID  The process ID.

       PPID The parent process ID.

       PGRP The process's group ID.

       SESSION (SESN)
            The process's session ID.

       TTY_NR (TTY)
            The controlling terminal of the process.

       TPGID
            The process ID of the foreground process group of the controlling terminal.

       STATE (S)
            The state of the process:
               S for sleeping (idle)
               R for running
               D for disk sleep (uninterruptible)
               Z for zombie (waiting for parent to read it's exit status)
               T for traced or suspended (e.g by SIGTSTP)
               W for paging

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

       NLWP The number of threads in the process.

       NICE (NI)
            The  nice  value of a process, from 19 (low priority) to -20 (high priority). A high value means the
            process is being nice, letting others have a higher relative  priority.  Only  root  can  lower  the
            value.

       PERCENT_CPU (CPU%)
            The percentage of the CPU time that the process is currently using.

       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.

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

       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
            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 kernels internal priority for the process, usually just it's nice value plus  twenty.  Different
            for real-time processes.

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

       M_SIZE (VIRT)
            Size in memory of the total program size.

       M_RESIDENT (RES)
            The resident set size, i.e the size of the text and data sections, plus stack usage.

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

       M_TRS (CODE)
            The size of the text segment of the process (i.e the size of the processes executable instructions).

       M_LRS (LIB)
            The library size of the process.

       M_DRS (DATA)
            The size of the data segment plus stack usage of the process.

       M_DT (DIRTY)
            The size of the dirty pages of the process.

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

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

       STARTTIME
            The time the process was started.

       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.

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

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

       IO_RATE (IO)
            The I/O rate, IO_READ_RATE + IO_WRITE_RATE (see above).

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

       CGROUP
            Which cgroup the process is in.

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

       VPID OpenVZ process ID.

       VXID VServer process ID.

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

AUTHORS

       htop is developed by Hisham Muhammad <loderunner@users.sourceforge.net>.

       This man page was written by Bartosz Fenski <fenio@o2.pl> for the Debian GNU/Linux distribution  (but  it
       may be used by others). It was updated by Hisham Muhammad, and later by Vincent Launchbury, who wrote the
       'Columns' section.