While I was working on curses text based graphical interfaces I came across two interesting Linux text applications:
- cowsay – generates ASCII pictures of a cow (or other animals) with a message
- jp2a – a small utility that converts JPG images to ASCII.
I this blog I wanted to document some of the things that I found and how these utilities could be used in a ncurses program.
Cowsay
Cowsay has been around in the Linux world since 2007. It is now available in Windows and Android. To install cowsay in Linux or a Rasberry Pi :
sudo apt-get install cowsay
Coway takes text messages that you pass it.
~$ cowsay "I'm not worried about mad cow...because I'm a helicopter"
_________________________________________
/ I'm not worried about mad cow...because \
\ I'm a helicopter /
-----------------------------------------
\ ^__^
\ (oo)\_______
(__)\ )\/\
||----w |
|| ||
If you install the Linux fortune app (sudo apt install fortune) you can pass random fortune messages:
~$ fortune | cowsay
_______________________________________
/ You get along very well with everyone \
\ except animals and people. /
---------------------------------------
\ ^__^
\ (oo)\_______
(__)\ )\/\
||----w |
|| ||
There are a number of different images that can be used. To see the list of what is available:
~$ cowsay -l
Cow files in /usr/share/cowsay/cows:
apt bud-frogs bunny calvin cheese cock cower daemon default dragon
dragon-and-cow duck elephant elephant-in-snake eyes flaming-sheep
ghostbusters gnu hellokitty kiss koala kosh luke-koala mech-and-cow milk
moofasa moose pony pony-smaller ren sheep skeleton snowman stegosaurus
stimpy suse three-eyes turkey turtle tux unipony unipony-smaller vader
vader-koala www
To display all the images:
~$ for i in $(cowsay -l); do cowsay -f $i "$i"; done
_____
< apt >
-----
\ (__)
(oo)
/------\/
/ | ||
* /\---/\
~~ ~~
___________
< bud-frogs >
-----------
\
\
oO)-. .-(Oo
/__ _\ /_ __\
\ \( | ()~() | )/ /
\__|\ | (-___-) | /|__/
' '--' ==`-'== '--' '
_______
< bunny >
-------
\
\ \
\ /\
( )
.( o ).
....and a bunch more
Cowsay in Python
There is a native Python cowsay library:
~$ pip install cowsay --user
An example from the Python command line:
>>> import cowsay
>>> cowsay.cow("This is from Python")
___________________
< This is from Python >
===================
\
\
^__^
(oo)\_______
(__)\ )\/\
||----w |
|| ||
Cowsay in a Curses App
As an example I wanted to make a Raspberry Pi intrusion monitor. First I created a cowsay images with some eyes:
~$ cowsay -f eyes "Raspberry Pi - Intrusion Monitor"
Once I was happy with the presentation I saved the output to a file:
~$ cowsay -f eyes “Raspberry Pi – Intrusion Monitor” > eyes.txt
In my Python curses app I read the eyes.txt file and used the stdscr.addstr method to write it to the screen. (Note: For more info on writing Python/C curses or Lua curses)
# c_eyes.py - create a curses with a cowsay message
#
import curses , time, random
# create a curses object
stdscr = curses.initscr()
height, width = stdscr.getmaxyx() # get the window size
# define two color pairs
curses.start_color()
curses.init_pair(1, curses.COLOR_RED, curses.COLOR_WHITE)
curses.init_pair(2, curses.COLOR_YELLOW, curses.COLOR_BLACK)
curses.init_pair(3, curses.COLOR_BLUE, curses.COLOR_BLACK)
# Read the cowsay output file and write it to the screen
f = open("eyes.txt", "r")
eyes = f.read()
stdscr.addstr(0, 0, eyes,curses.color_pair(3))
# Add a footer
stdscr.addstr(height-1, 0, " " * (width-1),curses.color_pair(1))
stdscr.addstr(height-1, 0, " Key Commands : q - to quit " ,curses.color_pair(1))
# Add intrusion code here....
stdscr.addstr(15, 5, "PIR1 input: no movement" ,curses.color_pair(2) )
stdscr.addstr(16, 5, "PIR2 input: no movement" ,curses.color_pair(2) )
curses.curs_set(0) # don't show the cursor
stdscr.refresh()
# Cycle to update text. Enter a 'q' to quit
k = 0
stdscr.nodelay(1)
while (k != ord('q')):
k = stdscr.getch()
curses.endwin()
jp2a – converts JPG images to ASCII
jp2a is a Linux utility that is installed by:
apt-get install jp2a
I found that you’ve got to be selective of the jpeg image that you are trying to convert an example of a castle:
jp2a castle.jpg --colors --background=light
Another example was to convert a flag. For this example I found the width option to be useful:
jp2a can.jpg --colors --width=70
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