#command #watch #command-output #monitoring #execute-command #ansi-colors #real-time

app hwatch

A modern alternative to the watch command, records the differences in execution results and can check this differences at after

20 releases

new 0.3.15 Jun 18, 2024
0.3.13 May 6, 2024
0.3.11 Mar 4, 2024
0.3.10 Apr 15, 2023
0.1.6 Oct 31, 2021

#190 in Command line utilities

Download history 32/week @ 2024-02-26 200/week @ 2024-03-04 49/week @ 2024-03-11 26/week @ 2024-03-18 6/week @ 2024-03-25 128/week @ 2024-04-01 96/week @ 2024-04-08 22/week @ 2024-04-15 18/week @ 2024-04-22 10/week @ 2024-04-29 225/week @ 2024-05-06 25/week @ 2024-05-13 25/week @ 2024-05-20 9/week @ 2024-05-27 170/week @ 2024-06-03 119/week @ 2024-06-10

324 downloads per month

Custom license



hwatch - alternative watch command.


hwatch is a alternative watch command. That records the result of command execution and can display it history and diffs.


  • Can keep the history when the difference, occurs and check it later.
  • Can check the difference in the history. The display method can be changed in real time.
  • Can output the execution result as log (json format).
  • Custom keymaps are available.
  • Support ANSI color code.
  • Execution result can be scroll.
  • Not only as a TUI application, but also to have the differences output as standard output.
  • If a difference occurs, you can have the specified command additionally executed.


macOS (brew)

brew install hwatch

macOS (MacPorts)

sudo port install hwatch

Arch Linux (AUR)

paru -S hwatch

Cargo Install

cargo install hwatch



    $ hwatch --help
    A modern alternative to the watch command, records the differences in execution results and can check this differences at after.

    Usage: hwatch [OPTIONS] [command]...


      -b, --batch                         output exection results to stdout
      -B, --beep                          beep if command has a change result
          --border                        Surround each pane with a border frame
          --with-scrollbar                When the border option is enabled, display scrollbar on the right side of watch pane.
          --mouse                         enable mouse wheel support. With this option, copying text with your terminal may be harder. Try holding the Shift key.
      -c, --color                         interpret ANSI color and style sequences
      -r, --reverse                       display text upside down.
      -C, --compress                      Compress data in memory.
      -t, --no-title                      hide the UI on start. Use `t` to toggle it.
      -N, --line-number                   show line number
          --no-help-banner                hide the "Display help with h key" message
      -x, --exec                          Run the command directly, not through the shell. Much like the `-x` option of the watch command.
      -O, --diff-output-only              Display only the lines with differences during `line` diff and `word` diff.
      -A, --aftercommand <after_command>  Executes the specified command if the output changes. Information about changes is stored in json format in environment variable ${HWATCH_DATA}.
      -l, --logfile [<logfile>]           logging file
      -s, --shell <shell_command>         shell to use at runtime. can  also insert the command to the location specified by {COMMAND}. [default: "sh -c"]
      -n, --interval <interval>           seconds to wait between updates [default: 2]
      -L, --limit <limit>                 Set the number of history records to keep. only work in watch mode. Set `0` for unlimited recording. (default: 5000) [default: 5000]
          --tab-size <tab_size>           Specifying tab display size [default: 4]
      -d, --differences [<differences>]   highlight changes between updates [possible values: none, watch, line, word]
      -o, --output [<output>]             Select command output. [default: output] [possible values: output, stdout, stderr]
      -K, --keymap <keymap>               Add keymap
      -h, --help                          Print help
      -V, --version                       Print version


Watch mode keybind(Default).

Key Action
, move selected screen(history/watch).
pageup, pagedn move selected screen(history/watch).
home, end move selected screen(history/watch).
Tab toggle select screen(history/watch).
select watch screen.
select history screen.
H show help window.
B toggle enable/disable border.
S toggle enable/disable border scrollbar.
C toggle color.
N switch line number display.
R toggle reverse mode.
M toggle mouse support.
D switch diff mode.
T toggle the UI (history pane and header).
Backspace toggle the history pane.
Q exit hwatch.
0 disable diff.
1 switch watch type diff.
2 switch line type diff.
3 switch word type diff.
O switch output mode(output->stdout->stderr).
Shift+O show only lines with differences(line/word diff mode only).
Shift+S show summary infomation in history.
F1 only stdout print.
F2 only stderr print.
F3 print output.
+ increase interval.
- decrease interval.
/ filter history by string.
* filter history by regex.
Esc unfiltering.
Ctrl+c cancel.

Custom keybind

Can customize key bindings by using the -K Option. Write it in the format keybind=funciton.

hwatch -K ctrl-p=history_pane_up -K ctrl-n=history_pane_down command...

Keybind functions that can be specified are as follows.

function description
up Move up
watch_pane_up Move up in watch pane
history_pane_up Move up in history pane
down Move down
watch_pane_down Move down in watch pane
history_pane_down Move down in history pane
page_up Move page up
watch_pane_page_up Move page up in watch pane
history_pane_page_up Move page up in history pane
page_down Move page down
watch_pane_page_down Move page down in watch pane
history_pane_page_down Move page down in history pane
move_top Move top
watch_pane_move_top Move top in watch pane
history_pane_move_top Move top in history pane
move_end Move end
watch_pane_move_end Move end in watch pane
history_pane_move_end Move end in history pane
toggle_forcus Toggle forcus window
forcus_watch_pane Forcus watch pane
forcus_history_pane Forcus history pane
quit Quit hwatch
reset filter reset
cancel Cancel
help Show and hide help window
toggle_color Toggle enable/disable ANSI Color
toggle_line_number Toggle enable/disable Line Number
toggle_reverse Toggle enable/disable text reverse
toggle_mouse_support Toggle enable/disable mouse support
toggle_view_pane_ui Toggle view header/history pane
toggle_view_header_pane Toggle view header pane
toggle_view_history_pane Toggle view history pane
toggle_border Toggle enable/disable border
toggle_scroll_bar Toggle enable/disable scroll bar
toggle_diff_mode Toggle diff mode
set_diff_mode_plane Set diff mode plane
set_diff_mode_watch Set diff mode watch
set_diff_mode_line Set diff mode line
set_diff_mode_word Set diff mode word
set_diff_only Set diff line only (line/word diff only)
toggle_output_mode Toggle output mode
set_output_mode_output Set output mode output
set_output_mode_stdout Set output mode stdout
set_output_mode_stderr Set output mode stderr
togge_history_summary Toggle history summary
interval_plus Interval +0.5sec
interval_minus Interval -0.5sec
change_filter_mode Change filter mode
change_regex_filter_mode Change regex filter mode


If you always want to use some command-line options, you can set them in the HWATCH environment variable. For example, if you use bash, you can add the following to your .bashrc:

export HWATCH="--no-title --color --no-help-banner --border --with-scrollbar"


interval 10 second

Use the -n option to specify the command execution interval.

hwatch -n 3 command...

logging output

The command execution result can be output as a log in json format.

hwatch -n 3 -l hwatch_log.json command...

When you check the json log, you can easily check it by using this script.

Use shell function

If you want the shell function to be executed periodically, you can specify the shell command to be executed with -s as follows.

# bash
hwatch -n 3 -s 'bash -c "source ~/.bashrc"; {COMMAND}' command...

# zsh
hwatch -n 3 -s 'zsh -c "source ~/.zshrc"; {COMMAND}' command...

ANSI Color code

If you want to see output colored with ANSI color code, enable color mode.

To enable color mode, run hwatch with the -c option. Alternatively, you can enable / disable the color mode with the C key during execution.

hwatch -n 3 -c command...

diff view

To enable color mode, run hwatch with the -d option.

There are several "diff modes" available. Switching can be done with the D key.

hwatch -n 3 -d command...

watch diff

line diff

word diff

history filtering

You can filter history as a string with / key and as a regular expression with * key.

run batch mode

You can have command diffs output directly to stdout instead with -b option of getting them as a TUI app.

hwatch -b command...


~1M SLoC