How to read a .properties file which contains keys that have a period character using Shell script

Question

I am trying to read a properties file from a shell script which contains a period (.) character like below:

# app.properties db.uat.user=saple user db.uat.passwd=secret   #/bin/sh function pause(){    read -p "$*" }  file="./app.properties"  if [ -f "$file" ] then     echo "$file found."  . $file  echo "User Id " $db.uat.user echo "user password =" $db.uat.passwd else     echo "$file not found." fi 

I have tried to parse the file after sourcing the file but it is not working since the keys contains the "." character and there are spaces in that value also.

My properties file always resides in the same directory of the script or somewhere in /usr/share/doc

Answer 1

I use simple grep inside function in bash script to receive properties from .properties file.

This properties file I use in two places - to setup dev environment and as application parameters.

I believe that grep may work slow in big loops but it solves my needs when I want to prepare dev environment.

Hope, someone will find this useful.

Example:

File: setup.sh

#!/bin/bash  ENV=${1:-dev}  function prop {     grep "${1}" env/${ENV}.properties|cut -d'=' -f2 }  docker create \     --name=myapp-storage \     -p $(prop 'app.storage.address'):$(prop 'app.storage.port'):9000 \     -h $(prop 'app.storage.host') \     -e STORAGE_ACCESS_KEY="$(prop 'app.storage.access-key')" \     -e STORAGE_SECRET_KEY="$(prop 'app.storage.secret-key')" \     -e STORAGE_BUCKET="$(prop 'app.storage.bucket')" \     -v "$(prop 'app.data-path')/storage":/app/storage \     myapp-storage:latest  docker create \     --name=myapp-database \     -p "$(prop 'app.database.address')":"$(prop 'app.database.port')":5432 \     -h "$(prop 'app.database.host')" \     -e POSTGRES_USER="$(prop 'app.database.user')" \     -e POSTGRES_PASSWORD="$(prop 'app.database.pass')" \     -e POSTGRES_DB="$(prop 'app.database.main')" \     -e PGDATA="/app/database" \     -v "$(prop 'app.data-path')/database":/app/database \     postgres:9.5 

File: env/dev.properties

app.data-path=/apps/myapp/  #========================================================== # Server properties #========================================================== app.server.address=127.0.0.70 app.server.host=dev.myapp.com app.server.port=8080  #========================================================== # Backend properties #========================================================== app.backend.address=127.0.0.70 app.backend.host=dev.myapp.com app.backend.port=8081 app.backend.maximum.threads=5  #========================================================== # Database properties #========================================================== app.database.address=127.0.0.70 app.database.host=database.myapp.com app.database.port=5432 app.database.user=dev-user-name app.database.pass=dev-password app.database.main=dev-database  #========================================================== # Storage properties #========================================================== app.storage.address=127.0.0.70 app.storage.host=storage.myapp.com app.storage.port=4569 app.storage.endpoint=http://storage.myapp.com:4569 app.storage.access-key=dev-access-key app.storage.secret-key=dev-secret-key app.storage.region=us-east-1 app.storage.bucket=dev-bucket 

Usage:

./setup.sh dev 

Answer 2

As (Bourne) shell variables cannot contain dots you can replace them by underscores. Read every line, translate . in the key to _ and evaluate.

#/bin/sh  file="./app.properties"  if [ -f "$file" ] then   echo "$file found."    while IFS='=' read -r key value   do     key=$(echo $key | tr '.' '_')     eval ${key}=\${value}   done < "$file"    echo "User Id       = " ${db_uat_user}   echo "user password = " ${db_uat_passwd} else   echo "$file not found." fi 

Note that the above only translates . to _, if you have a more complex format you may want to use additional translations. I recently had to parse a full Ant properties file with lots of nasty characters, and there I had to use:

key=$(echo $key | tr .-/ _ | tr -cd 'A-Za-z0-9_')