Cat
Tail-f
Log file description
- /var/log/message system startup information and error log, which is one of the most commonly used logs in red Hat Linux
- /var/log/secure Security-related log information
- /var/log/maillog message-related log information
- /var/log/cron log information related to timed tasks
- /var/log/spooler log information related to UUCP and news devices
- /var/log/boot.log Daemon starts and stops related log messages
System:
- # uname-a # View kernel/Os/cpu information
- # cat/etc/issue
- # cat/etc/redhat-release # view OS version
- # cat/proc/cpuinfo # View CPU Information
- # hostname # View computer name
- # LSPCI-TV # list all PCI devices
- # LSUSB-TV # list all USB devices
- # lsmod # List of loaded kernel modules
- # env # View Environment variables
Resources:
- # free-m # View memory usage and swap area usage
- # df-h # View the usage of each partition
- # Du-sh < directory name > # View the size of the specified directory
- # grep Memtotal/proc/meminfo # View Total Memory
- # grep Memfree/proc/meminfo # View the amount of free memory
- # uptime # View System uptime, number of users, load
- # cat/proc/loadavg # View System load
Disks and partitions:
- # Mount | COLUMN-T # Viewing the status of a mounted partition
- # fdisk-l # View all partitions
- # swapon-s # View all swap partitions
- # hdparm-i/dev/hda # View disk parameters (for IDE devices only)
- # DMESG | grep IDE # View IDE device detection status at startup
Internet:
- # ifconfig # View the properties of all network interfaces
- # iptables-l # View firewall settings
- # route-n # View the routing table
- # netstat-lntp # View all listening ports
- # NETSTAT-ANTP # View all established connections
- # netstat-s # View Network statistics
Process:
- # ps-ef # View All Processes
- # top # Real-time display of process status (in another article there is a detailed introduction)
User:
- # w # View active Users
- # ID < user name > # View specified user information
- # last # View user log in log
- # cut-d:-f1/etc/passwd # View All users of the system
- # cut-d:-f1/etc/group # View all system groups
- # crontab-l # View Current user's scheduled tasks
Service:
- # chkconfig–list # List all system services
- # Chkconfig–list | grep on # Lists all startup system services
Program:
- # rpm-qa # View all installed Packages
How to view logs in a Linux system (common commands)