Linux debugging command (리눅스 디버깅 커맨드)

Linux Debugging Commands You Should Know

1. Checking Process and System Status

• top / htop : Monitor real-time process CPU and memory usage
• ps aux : View a list of running processes
• pidstat : Analyze CPU usage of a specific process
• vmstat : Monitor system performance and resource usage
• iostat : Check disk I/O status
• free -m : Check memory usage
• uptime : Display system uptime and load average

2. Checking and Analyzing Logs

• dmesg | less : View kernel logs (boot, drivers, hardware issues, etc.)
• journalctl -xe : View system logs (for systemd-based environments)
• tail -f /var/log/syslog : Monitor system logs in real-time
• cat /var/log/messages : View general system logs
• grep "error" /var/log/syslog : Search logs for specific keywords

3. Network Debugging

• ping <IP> : Check network connectivity
• traceroute <IP> : Trace network route
• netstat -tulnp : View open ports and network connections
• ss -tulnp : Faster alternative to netstat
• lsof -i :<port> : Check which process is using a specific port
• tcpdump -i eth0 port 80 : Capture network packets
• wireshark : GUI-based network packet analysis tool
• ifconfig / ip a : Check network interface status

4. File and Directory Debugging

• ls -lah : Display detailed file and directory information
• stat <filename> : Check file attributes and timestamps
• df -h : Check disk usage
• du -sh <directory> : Check the size of a specific directory
• find /path -name "*.log" : Search for specific files
• inotifywait -m <file> : Monitor real-time file changes

5. Memory and Process Debugging

• strace -p <PID> : Trace system calls of a process
• ltrace -p <PID> : Trace library function calls of a process
• gdb <executable> : Debug programs with GNU Debugger
• valgrind --leak-check=full ./program : Detect memory leaks
• pmap -x <PID> : Check memory mapping of a process
• cat /proc/<PID>/maps : View memory mapping details

6. File System and Disk Checking

• fsck /dev/sdX : Check and repair filesystem errors
• mount | grep <directory> : Check mounted filesystems
• blkid : Check disk UUID and type
• hdparm -I /dev/sdX : Get disk information
• smartctl -a /dev/sdX : Check S.M.A.R.T. disk health status

7. CPU and Performance Profiling

• perf top : Monitor real-time CPU performance
• perf record -g ./program && perf report : Performance analysis and reporting
• time ./program : Measure execution time
• mpstat -P ALL : Check per-core CPU usage

8. Kernel Debugging

• cat /proc/cpuinfo : Check CPU information
• cat /proc/meminfo : Check memory information
• lsmod : View loaded kernel modules
• modinfo <module_name> : Get details of a specific kernel module
• insmod <module.ko> / rmmod <module_name> : Load and unload kernel modules

9. Debugging Tools

• gdb : GNU Debugger
• valgrind : Memory leak detection and performance analysis tool
• rr : Reverse debugging tool
• SystemTap : Dynamic kernel analysis tool
• bpftrace : eBPF-based performance analysis

Using these commands depending on your debugging needs will help you troubleshoot issues effectively! 🚀