Replace line in file with line in another file based on matching string

Shell Programming and Scripting
1

HI

Can any one guide me how to achieve this task. I have 2 files

env.txt
#Configuration.Properties values
identity_server_url = http://identity.test-hit.com:9783/identity/service/user/register
randon_password_length = 6
attachment_file_path = /pass/temp/attachments/
documentation.services.basePath=http://appserver3.test-d.hit.com:9863/cirrus/service
documentation.services.version=2.0
user.registration.alert.path=emailtemplates/welcomeuser.vm

configuration.properties
identity_server_url = http://identity.test1-hit.com:9883/identity/service/user/register
randon_password_length = 8
attachment_file_path = /pass/temp/attachments/
documentation.services.basePath=http://appserver2.test1-d.hit.com:9863/cirrus/service
documentation.services.version=1.0
user.registration.alert.path=emailtemplates/welcomeuser.vm

In the above configuration.properties file i need to replace the line "identity_server_url" with env.txt file content. In configuration.properites file before '=' values are constant. After '=' values are changing. So i need to replace the line with matched string before '=' in configuration.properties with env.txt

Thanks
Nikil

2

Could you please show us your attempts at solving the problem. Thanks.