_             _ _  _            ___ _   
| |-.---.---.-| | ||-|---.---.  | __| |-.
|   | -_| - | - | || |   | -_| _|__ |   |
|_|_|___|__.|__.|__|_|_|_|___||_|___|_|_|

headline.sh is a small Bash shell script to print banner text to the terminal in different fonts.

Examples

The default font is called Shell Sans (in file shell-sans.sf) and is expected to be in the same directory as the main script.

./headline.sh 'bash rules!'
 _       ___ _             _      ___  _ 
| |-.---| __| |-. .---.-.-| |.---| __|| |
| - | - |__ |   | |  _| | | || -_|__ ||_|
|.__|__.|___|_|_| |_| |__.|__|___|___||_|

You can also change the font by setting the HEADLINE_FONT environment variable:

HEADLINE_FONT=midnight.sf ./headline.sh Midnight
┌─┬─┐     ┐           ┐      
│ │ │ .   │     .     │      
│ │ │ ┐ ┌─┤ ┬─┐ ┐ ┌─┬ ├─┐ ┼  
│ │ │ │ │ │ │ │ │ │ │ │ │ │  
┴   ┴ ┴ └─┴ ┴ ┴ ┴ └─┤ ┴ ┴ └┘ 
                   ─┘

Font format

Font files are themselves simple Bash scripts that are sourced from the main script. They define a few variables followed by the raw font data in heredoc syntax.

The format for a font with only the letters 'a' and 'b' looks like this:

# Letter height of the font in terminal lines
letter_height=1
# Number of the first line of this file with actual font data 
data_start=13
# The characters this font defines
characters='ab'
# Simple kerning support, see below. Not used in this font.
declare -A kern_map=()
kern_width=1
# Make this file sourceable. After this line, headline.sh expects
# length(characters) * letter_height lines of font data.
return; cat <<EOF
a 
b 
EOF

The lines defining each letter should be of the same lenght and end in the amount of whitespace that optimally separates adjacent letters in the final output.

"Kerning"

If you want -- like in Shell Sans - letters to line up and/or merge nicely, there is some faux kerning support. To use this, first decide on a "kerning width", which is the number of trailing characters of each letter definition to be looked at for kerning, the default being 1. headline.sh first renders the text as if no kerning was specified. Sub-strings are then replaced according to the defined kern_map. Each key consists of 2 * kern_with characters to be replaced at the end of each letter. The value specifies the replacement characters. Unmapped strings get replaced with whitespace.

Shell Sans defines its kern_map as follows:

declare -A kern_map=( ['|.']='|' ['. ']='.' ['| ']='|' ['/ ']='/' ['\ ']='\')

Compare Shell Sans with and without kern_map:

headline.sh a b  | HEADLINE_FONT=/tmp/nokern.sf headline.sh a b
       _         |        _   
.---. | |-.      | .---  | |-.
| - | | - |      | | -   | - |
|__.| |.__|      | |__.  |.__|

The version with kerning replaced the combination . and | with . and |, respectively.

Bugs

• Many missing characters. Completed so far are:
  • Digital: .:ABCDEFGHIJKLMNOPQRSTUVWXYZ
  • Shell Sans: !"#$%+,-.12345:;[]_abcdefghijklmnopqrstuvwxyz|äöüCNST
  • Midnight: dghintM
  • Null: -_.!|abcdefghijklmnopqrstuvwxyzäöüCNST
• Uses Bash-isms
• Error messages could be nicer
• No distribution packages

Copyright/License

headline.sh version 0.3 Copyright (c)2015-2020 Christian Blichmann headline-sh@blichmann.eu

headline.sh is licensed under a two-clause BSD license, see the LICENSE file for details.