readline_write_history() writes readline history entries to a file. This guide explains the function with focused examples and the decisions that matter in real applications.
What Is readline_write_history() in PHP?
Writes readline history entries to a file.
A typical call looks like this:
<?php
readline_write_history([$filename]);
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_write_history() directly to demonstrate its basic purpose.
<?php
readline_add_history("status"); readline_write_history(sys_get_temp_dir() . "/demo-history.txt");
The returned value illustrates writes readline history entries to a file. Protect the history file with appropriate permissions.
Example 2: A Different Input or Option
The next example changes the input or option, showing another supported use of readline_write_history().
<?php
readline_add_history("help"); var_dump(readline_write_history(__DIR__ . "/cli-history.txt"));
The returned value illustrates writes readline history entries to a file. Protect the history file with appropriate permissions.
Practical Example: Applying the Function
In application code, readline_write_history() belongs in a controlled workflow with input validation, a checked result and cleanup where needed.
<?php
$historyPath = sys_get_temp_dir() . "/commands-history.txt"; readline_write_history($historyPath); echo "Saved history";
The returned value illustrates writes readline history entries to a file. Protect the history file with appropriate permissions.
Important Behavior and Edge Cases
- Main behavior: Writes readline history entries to a file.
- Important limitation: Protect the history file with appropriate permissions.
- 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_write_history() | Writes readline history entries to a file. |
readline_read_history | Loads readline history entries from a file. |
Common Beginner Mistakes
| Mistake | Correct Approach |
|---|---|
Ignoring the specific limits or preconditions of readline_write_history(). | Protect the history file with appropriate permissions. |
| 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
- Writes readline history entries to a file.
- Protect the history file with appropriate permissions.
- This function uses the CLI readline extension; it is not designed for an ordinary web request.
Use readline_write_history() 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.