Dos Batch to Shell Script

How to convert following dos batch code to unix shell:-

echo Database username and password will be taken from liquibase.properties file....
setlocal ENABLEEXTENSIONS
for /f "tokens=1* delims==" %%a in (liquibase.properties) do (
if "%%a"=="username" set dbuser=%%b
if "%%a"=="password" set dbpwd=%%b
if "%%a"=="url" set dburl=%%b
)
echo.
echo UserName is:=%dbuser%
echo PassWord is:=%dbpwd%
echo URL is:=%dburl%
echo.
if not %errorlevel%==0 goto ON_FILE_READ_ERROR



Regards
Dattatraya