Master Breakpoints in GDB: Set, Manage, and Use Like a Pro (Linux Debug Guide)

GDB Breakpoints

GDB (GNU Debugger) is the go-to tool for debugging C and C++ programs on Linux. One of the most powerful features it offers is the breakpoint—a marker that tells the debugger to pause execution at a specific line or condition.

Breakpoints help you:

  • Inspect variables at critical code lines
  • Step through logic in real time
  • Detect and fix segmentation faults, memory issues, or logic bugs

In this guide, we’ll cover how to:

  • Set basic, conditional, and temporary breakpoints
  • Break by file, line, or function
  • Enable, disable, and delete breakpoints

🛠️ Step 1: Launch Your Program in GDB

Compile your code with debug symbols:

gcc -g main.c -o main

Launch GDB:

gdb ./main

🎯 Types of Breakpoints in GDB

✅ 1. Breakpoint by Line Number

break 15

⏱ Pauses execution at line 15 of the currently loaded file.

✅ 2. Breakpoint in Specific File and Line

break utils.c:42

🎯 Useful for multi-file programs.

✅ 3. Breakpoint by Function Name

break my_function

Breaks at the beginning of the specified function.

✅ 4. Conditional Breakpoint

break my_function if x > 10

⛔️ Only breaks if the condition is true when function is called.

✅ 5. Temporary Breakpoint

tbreak main

💡 This breakpoint will be removed after it’s hit once. Great for entry points or quick checks.

✅ 6. Breakpoint at a Memory Address

break *0x080484c6

Advanced use case: debugging low-level or assembly code.

⚙️ Manage Breakpoints

List All Breakpoints:

info breakpoints

Disable a Breakpoint:

disable 2

Enable Again:

enable 2

Delete a Breakpoint:

delete 2

💡 Replace 2 with your breakpoint number (from info breakpoints).

🔄 Bonus: Breakpoint Commands

You can attach actions to a breakpoint:

break update_score
commands
  print score
  continue
end

📌 This will print score every time update_score() is hit, and continue execution.

Breakpoints are the backbone of efficient debugging in GDB. Whether you’re working on a simple main.c or a multi-module project, mastering different types of breakpoints helps you diagnose issues faster, analyze control flow, and build better programs.

What’s your favorite GDB trick?
Have a breakpoint use case you’d like help with?
Drop your thoughts and questions in the comments below! 🔧🧑‍💻

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