gistfile1.sh

# !/bin/bash

#  # figlet-dialog - A "graphical" figlet frontend.

#  ## Intro

#  So I wanted to learn some shell/bash scripting. I found this
# program called `dialog`, which would allow me to make "GUI"s in
# shell, so I decided to make something with it.
#  The following program is a `figlet` GUI. It will display a textbox
# for your message, and a list of fonts to select.
#  Eventually this also turned into a litterate programming exercise.

#  ## Program

#  ### Initial code

#  First I list the fonts you can choose from.
#  This is just an array with the names of the fonts. To add a font,
# just add it to the list.
fonts=( standard banner script term )

#  #### The font-tag list

#  Since `display` needs a "tag" for each element in the list (and
# it needs the list in a "tag1 name1 tag2 name2"-string) I have to
# iterate over the list and format it.
#  I'm 100% certain this could be done in awk. Guess there are things
# to do in v2

#  n starts at one, because it looks nicer.
n=1
font_tag_list=""

for index in ${fonts[@]}
#  The "${fonts[@]}" says returns all elements in the font, so it
# can be iterated over.

do
  #  Here we make the string with the tags and names. Notice how
  # bash is untyped, i.e. there are no types and things are combined
  # as needed (Weird like Javascript).
  font_tag_list=$font_tag_list" "$n" "$index
  let "n += 1" # Increase n by one (1).
done

#  ### "GUI"

#  With the list of fonts ready, the GUI can be set up. It isn't truly
# a GUI, since it's all text based. Using something like `gdialog`
# og `xdialog` would allow me to make GUIs.

#  Anyway, first I ask for the message that is going to be printed.
message=`dialog --inputbox "What message to print?" 6 40 --stdout`
#  The `--stdout` is needed because the output is going to be saved
# in a variable. If another program was piped to it, the flag would
# be needed too.

#  Next up is the font. `$font_tag_list` expands to the
# space-seperated tag-name pairs.
font=`dialog --menu "Choose a font." 11 40 $n\
            $font_tag_list\
            --stdout`
#  The `$n` is needed because `dialog` needs to know how many pairs
# there are.

#  The terminal is cleared so the GUI doesn't mess up the terminal.
clear

#  ### Printing

#  Printing is done using `figlet` which has many, many fonts. The
# fonts are ASCII-art fonts, but they are still fairly complex.
#  Before the message can be printed, there is one minor tweak.
#  The list of fonts was zero-indexed, and the list in the GUI
# was one-indexed, I need to substract 1 to get the font from the
# original list.
let "font -= 1"

#  Finally I can print the font with `figlet`
figlet $message -f ${fonts[$font]}

#  That's it!

#  ##References
#  Advanced Bash-Scripting Guide:
# http://tldp.org/LDP/abs/html/index.html
#  dialog man page: http://linux.die.net/man/1/dialog
#  Dialog: An Introductory Tutorial:
# http://www.linuxjournal.com/article/2807
#  FIGlet fonts library: http://www.jave.de/figlet/fonts/overview.html