📂 PHP File Open / Read / Close

In PHP, file handling allows you to open, read, write, and close files stored on the server.
This is very important for logs, configuration files, data storage, and real-world applications.

---

1️⃣ What is File Handling in PHP?

File handling in PHP means:

• Opening a file

• Reading data from it

• Writing data to it

• Closing the file

📌 PHP provides built-in functions for file handling.

---

2️⃣ File Open – fopen() ⭐

Syntax

Common File Modes

---

Example: Open a File

---

3️⃣ File Read – fread() ⭐

Syntax

Example: Read Entire File

✔ Reads full content of the file

---

4️⃣ Read File Line by Line – fgets() ⭐

✔ Very useful for large files

---

5️⃣ Read File Character by Character – fgetc()

---

6️⃣ File Close – fclose() ⭐

Syntax

Why Close a File?

✔ Frees server memory
✔ Prevents file corruption
✔ Good programming practice

📌 Always close files after use.

---

7️⃣ Shortcut Functions (Very Common)

file_get_contents() ⭐

Reads entire file in one line.

readfile()

Reads and outputs file directly.

---

8️⃣ File Exists Check – file_exists()

✔ Avoids runtime errors

---

9️⃣ Error Handling with Files ⭐

---

🔟 Common Mistakes ❌

❌ Forgetting to close file
❌ Using wrong file mode
❌ Not checking file existence
❌ Reading large files with fread()

---

📌 Interview Questions & MCQs (Very Important)

Q1. Which function opens a file in PHP?

A) open()
B) file()
C) fopen()
D) read()

✅ Answer: C

---

Q2. Which mode opens a file for reading only?

A) w
B) a
C) r
D) x

✅ Answer: C

---

Q3. Which function reads a file line by line?

A) fread()
B) fgets()
C) fgetc()
D) readfile()

✅ Answer: B

---

Q4. Which function closes a file?

A) close()
B) stop()
C) end()
D) fclose()

✅ Answer: D

---

Q5. Which function reads entire file easily?

A) fread()
B) file_get_contents()
C) fgets()
D) fopen()

✅ Answer: B

---

Q6. Why is fclose() important?

A) Speeds PHP
B) Frees memory
C) Prevents corruption
D) All of the above

✅ Answer: D

---

🔥 Real-Life Use Cases

✔ Reading configuration files
✔ Displaying text files
✔ Logging user activity
✔ File-based data storage

---

✅ Summary

• fopen() → open file

• fread(), fgets(), fgetc() → read file

• fclose() → close file

• Always check file existence

• Use shortcut functions for simplicity

• Very important for PHP exams & interviews