Debugging C/C++ Programs with GDB

If you don't use GDB but program in C/C++, you are missing out on a powerful debugging tool. Here's a quick 5-minute tutorial to get you started.

Step 1: Compile with Debug Symbols

Compile your program using the -ggdb flag to include debug symbols for GDB.

# For C++
g++ main.cpp -o main -ggdb

# For C
gcc main.c -o main -ggdb

Step 2: Run GDB

Now, run GDB from the shell, pointing it to your compiled executable.

gdb ./main

(Note: If you aren't using Linux, at least consider using WSL (Windows Subsystem for Linux) for a better debugging experience.)

You will see the (gdb) prompt.

Step 3: Basic GDB Commands

• Type run to execute your program.
• Use break followed by a line number or function name to set breakpoints.
• Type n to step through the code line by line.

Step 4: Visualize Code with layout split

One helpful feature is the split layout, which displays both the source code and GDB commands simultaneously.

layout split

Step 5: Inspecting Variables

Use the print and display commands in GDB to inspect variables and expressions during debugging.

For example:

print variable_name
display expression

These commands help you check if anything is unexpected in your program.

Now go practice!!!