Summary - File handling
- PHP course
- Intermediate
- Lesson 75/115
- 5 min
Build a journal app with file_get_contents, file_put_contents and fopen.
Summary: the file handling toolkit
In this group you learned two approaches to file handling:
- One-shot: read the file as a string with
file_get_contents()and write a string withfile_put_contents(). Ideal for short and simple tasks. - Handle-based: open with
fopen(), work withfwrite()/fread(), close withfclose(). Used when step-by-step reading or different modes are needed.
Now we will build a small journal app that combines both approaches.
Practice Journal — one-shot approach
Write two entries to journal.txt. Write the first entry with file_put_contents() as 'Journal started' . PHP_EOL (resets the file). Append the second entry with the append flag as 'Learned PHP today.' . PHP_EOL. Then read the file with file_get_contents() and print it with echo.
Starter code
<?php
$file = __DIR__ . '/journal.txt';
// Write the first entry
// Append the second entry with the append flag
// Read the file and print itSample solution
<?php
$file = __DIR__ . '/journal.txt';
// Write the first entry
file_put_contents($file, 'Journal started' . PHP_EOL);
// Append the second entry with FILE_APPEND
file_put_contents($file, 'Learned PHP today.' . PHP_EOL, FILE_APPEND);
// Read the file and print it
echo file_get_contents($file);Expected output
Journal started Learned PHP today.
Recap of the handle-based flow
The handle-based approach has four steps:
- Open in the right mode (
'r','w','a') withfopen(). - Write with
fwrite()or read withfread(). - Reopen in a different mode if needed.
- Close with
fclose().
This flow gives flexibility through mode choice and prevents handles from staying open. Now we will build the same journal with handles.
Practice Journal — handle-based approach
Open notes.txt with fopen() in 'w' mode and assign the handle to $wr. Use fwrite() to write 'First line' . PHP_EOL, then fwrite() again to write 'Second line' . PHP_EOL. Close with fclose($wr). Then open the file in 'r' mode, assign the handle to $rd, read 50 bytes with fread() into $content, close with fclose($rd) and print with echo $content.
Starter code
<?php
$file = __DIR__ . '/notes.txt';
// Open in write mode
$wr = null;
// Write two lines and close
// Open in read mode
$rd = null;
// Read 50 bytes, close and printSample solution
<?php
$file = __DIR__ . '/notes.txt';
// Open in write mode
$wr = fopen($file, 'w');
// Write two lines and close
fwrite($wr, 'First line' . PHP_EOL);
fwrite($wr, 'Second line' . PHP_EOL);
fclose($wr);
// Open in read mode
$rd = fopen($file, 'r');
// Read 50 bytes, close and print
$content = fread($rd, 50);
fclose($rd);
echo $content;Expected output
First line Second line
Questions and answers
Review the lesson questions together with their answers. To test yourself, solve the lesson interactively.
1 Match functions to their jobs
| Term | Meaning |
|---|---|
file_get_contents() |
Reads whole file as a string |
file_put_contents() |
Writes a string to a file |
fopen() |
Opens a file in a specific mode |
fclose() |
Closes the handle |
2 You want to first write to a file and then read it back. What is the correct order?
- fopen('r') → fwrite → fread → fclose
- fopen('w') → fread → fclose → fopen('r') → fwrite → fclose
- fopen('w') → fwrite → fclose → fopen('r') → fread → fclose Correct answer
- fopen('a') → fwrite → fread → fclose
Explanation: Open in write mode and close, then open in read mode and close.