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How to use gdb in Ubuntu Terminal

Here's a practical, minimal guide for using GDB in Ubuntu terminal — from launching to setting breakpoints and navigating your code. 🧰 Step 1: Compile with Debug Symbols Use -g and disable optimizations ( -O0 preferred for debugging): bash Copy Edit g++ -g -O0 -o myprog myprog.cpp 🚀 Step 2: Launch GDB bash Copy Edit gdb ./myprog You'll see a (gdb) prompt. 🎯 Step 3: Set Breakpoints You can set breakpoints in three main ways : ✅ a. At a function gdb Copy Edit (gdb) break main ✅ b. At a specific file and line gdb Copy Edit (gdb) break myprog.cpp:42 ✅ c. At a method in a class gdb Copy Edit (gdb) break MyClass::doSomething If the symbol is mangled (C++), GDB usually demangles automatically, especially if compiled with -g . ▶️ Step 4: Run the Program gdb Copy Edit (gdb) run 🧭 Step 5: Navigate Command Meaning next or n Step over current line step or s Step into function call finish Run until current function returns continue or c Continue until...
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Common screen commands

 To create screen

screen -S <screen_name>

To detach screen

Ctrl+A d

To list screens

screen -ls

To reattch screen

screen -r <screen_name>

To detach screen already attached in some other [SSH] session

screen -d <screen_name>

To kill a screen session

screen -X -S <screen_name>; or screen -X -S <screen_name> quit

To switch to a screen

screen -r <screen_name>

Note: <screen_name> can be screenName or screenId as you get from "screen -ls" command

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If you have any doubts, please let me know.

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