readline_on_new_line() tells readline that output moved to a new line before redrawing the prompt. This guide explains the function with focused examples and the decisions that matter in real applications.
What Is readline_on_new_line() in PHP?
Tells readline that output moved to a new line before redrawing the prompt.
A typical call looks like this:
<?php
readline_on_new_line();
The input arguments shown in the call identify the relevant connection, resource, value, path or configuration for the operation. Pay attention to argument order and to the return value demonstrated below.
Example 1: Basic Usage
This first example uses readline_on_new_line() directly to demonstrate its basic purpose.
<?php
echo "Notice" . PHP_EOL; readline_on_new_line();
The returned value illustrates tells readline that output moved to a new line before redrawing the prompt. Use with readline redisplay logic, not as a general echo replacement.
Example 2: A Different Input or Option
The next example changes the input or option, showing another supported use of readline_on_new_line().
<?php
fwrite(STDOUT, "Updated" . PHP_EOL); readline_on_new_line();
The returned value illustrates tells readline that output moved to a new line before redrawing the prompt. Use with readline redisplay logic, not as a general echo replacement.
Practical Example: Applying the Function
In application code, readline_on_new_line() belongs in a controlled workflow with input validation, a checked result and cleanup where needed.
<?php
echo "Background message" . PHP_EOL; readline_on_new_line(); readline_redisplay();
The returned value illustrates tells readline that output moved to a new line before redrawing the prompt. Use with readline redisplay logic, not as a general echo replacement.
Important Behavior and Edge Cases
- Main behavior: Tells readline that output moved to a new line before redrawing the prompt.
- Important limitation: Use with readline redisplay logic, not as a general echo replacement.
- Requirements: This function uses the CLI readline extension; it is not designed for an ordinary web request.
Comparison With Related Functions
| Function or Approach | When to Use It |
|---|---|
readline_on_new_line() | Tells readline that output moved to a new line before redrawing the prompt. |
readline_redisplay | Refreshes the readline prompt display after changes to terminal output. |
Common Beginner Mistakes
| Mistake | Correct Approach |
|---|---|
Ignoring the specific limits or preconditions of readline_on_new_line(). | Use with readline redisplay logic, not as a general echo replacement. |
| Assuming every environment produces the same result. | This function uses the CLI readline extension; it is not designed for an ordinary web request. |
Key Takeaways
- Tells readline that output moved to a new line before redrawing the prompt.
- Use with readline redisplay logic, not as a general echo replacement.
- This function uses the CLI readline extension; it is not designed for an ordinary web request.
Use readline_on_new_line() when its behavior matches your task, and verify the relevant return value before taking further action. The output depends on the local configuration when it uses resources, files or an interactive terminal.