Append or Prepend Text Line in File

Use this predefined action to add one or more text lines to the beginning or end of a file during installation.

A common use case is updating C:\Windows\System32\drivers\etc\services to add custom ports for an application.

Main Fields

Field	Description
Action Name	Identifies the predefined action when the project contains multiple custom actions.
Path	Specifies the full path to the file that will be updated.
Placement	Chooses Append to add lines at the end of the file or Prepend to insert them at the beginning.
Check if line already exists in file	Prevents duplicate lines from being added.
Non-case sensitive	Ignores letter case when checking whether a line already exists.

Text Lines

The Text lines list contains the exact lines that will be written to the file.

Manage Text Lines

Use the toolbar to add, edit, or remove lines.

Encoding

Choose the correct encoding, such as UTF-8 or ANSI, so the updated file keeps the expected character set.

Steps

1. Open the MSI or MST in Master Packager.
2. In the left pane, select Custom Actions.
3. Open the Predefined Actions tab.
4. Click Add New Predefined Action and select Append or Prepend Text Line in File.
5. Enter a value in Action Name.
6. Set Path to the file that should be updated.
7. Add the required entries under Text lines.
8. Choose the appropriate Encoding.
9. Select Placement.
10. Optionally enable Check if line already exists in file and Non-case sensitive.