The best way to create a multiline document template (shell)

Demo: String Templates in Bash .md

Demo: String Templates in Bash

The best way to create a multiline string template variable which has variables within it and contains double quotes.

IMPORTANT: The variable inserts must be assigned before the string template is declared and before it's used! EACH TIME THE INSERTS ARE MODIFIED, THE TEMPLATE MUST BE RE-RECLARED! For this reason it's sometimes handy to put the template def inside a function so you can call/re-call it before using it.

doc_template.sh

#!/bin/sh
# doc_template.sh

# the best way to create a multiline string template variable which has 
# variables within it and double quotes is seen here with PACKAGE_JSON. 
# This can then be printed out or written to a file as you can see on the 
# bottom of this page. 

# IMPORTANT: The variable inserts must be assigned before the string template 
# is declared and before it's used! EACH TIME THE INSERTS ARE MODIFIED, THE
# TEMPLATE MUST BE RE-RECLARED! For this reason it's sometimes handy to put 
# the template def inside a function so you can call/re-call it before using it. 


PROJ="proj name"
DESC="description ..."
OWNER="author name"
NAME="contributor name"
EMAIL="[email protected]"
URL="http://www.somecrap.com"


PACKAGE_JSON=$(cat <<EOF
{
  "name": "$PROJ",
  "version": "0.0.1",
  "description": "$DESC",
  "author": "$OWNER <$EMAIL>",
    "contributors": [{
    "name": "$NAME",
    "email": "$EMAIL"
  }],
  "main": "app.js",
  "scripts": {
    "test": "echo \"Error: no test specified\" && exit 1"
  },
  "repository": {
    "type": "git",
    "url": "$URL"
  },
  "private": "true",
  "license": "MIT"
}
EOF
)

# must use doublequotes!
printf "$PACKAGE_JSON"

# must use doublequotes here too!
printf "$PACKAGE_JSON" > newfile.txt

Thanks a lot. This is the definite answer. All the answers on StackOverflow and StackExchange are over-complicated bullshit.