系统

# uname -a                                                             # 查看内核/操作系统/CPU信息
# head -n 1 /etc/issue                                                 # 查看操作系统版本
# cat /proc/cpuinfo                                                    # 查看CPU信息
# hostname                                                             # 查看计算机名
# lspci -tv                                                            # 列出所有PCI设备
# lsusb -tv                                                            # 列出所有USB设备
# lsmod                                                                # 列出加载的内核模块
# env                                                                  # 查看环境变量

资源

# free -m                                                              # 查看内存使用量和交换区使用量
# df -h                                                                # 查看各分区使用情况
# du -sh <目录名>                                                      # 查看指定目录的大小
# grep MemTotal /proc/meminfo                                          # 查看内存总量
# grep MemFree /proc/meminfo                                           # 查看空闲内存量
# uptime                                                               # 查看系统运行时间、用户数、负载
# cat /proc/loadavg                                                    # 查看系统负载

磁盘和分区

# mount | column -t                                                    # 查看挂接的分区状态
# fdisk -l                                                             # 查看所有分区
# swapon -s                                                            # 查看所有交换分区
# hdparm -i /dev/hda                                                   # 查看磁盘参数(仅适用于IDE设备)
# dmesg | grep IDE                                                     # 查看启动时IDE设备检测状况

网络

# ifconfig                                                             # 查看所有网络接口的属性
# iptables -L                                                          # 查看防火墙设置
# route -n                                                             # 查看路由表
# netstat -lntp                                                        # 查看所有监听端口
# netstat -antp                                                        # 查看所有已经建立的连接
# netstat -s                                                           # 查看网络统计信息

进程

# ps -ef                                                               # 查看所有进程
# top                                                                  # 实时显示进程状态

用户

# w                                                                    # 查看活动用户
# id <用户名>                                                          # 查看指定用户信息
# last                                                                 # 查看用户登录日志
# cut -d: -f1 /etc/passwd                                              # 查看系统所有用户
# cut -d: -f1 /etc/group                                               # 查看系统所有组
# crontab -l                                                           # 查看当前用户的计划任务

服务

# chkconfig –list                                                     # 列出所有系统服务
# chkconfig –list | grep on                                           # 列出所有启动的系统服务
程序

# rpm -qa                                                              # 查看所有安装的软件包