System command:
# Uname-a # view kernel/OS/CPU information # head-n 1/etc/issue # 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 loaded kernel modules # env # view environment variables
Resource command:
# Free-m # view memory usage and swap zone usage # df-h # view the usage of each partition # du-sh # view the size of a specified directory # grep MemTotal/proc/meminfo # View total memory # grep MemFree/proc/meminfo # view the Amount of idle memory # uptime # view the system running time, number of users, and load # cat/proc/loadavg # view the system load
Disks and partitions
# Mount | column-t # view the status of the mounted partition # fdisk-l # view all partitions # swapon-s # view all swap partitions # hdparm-I/dev/hda # view disk parameter (applicable only to IDE devices) # dmesg | grep IDE # view the IDE Device Detection Status at startup
Network:
# Ifconfig # view the attributes of all network interfaces # iptables-L # view firewall settings # route-n # view route tables # netstat-lntp # view all listening ports # netstat-antp # view all established connection # netstat-s # view network statistics
Process:
# Ps-ef # view all processes # top # display Process status in real time
User:
# W # view active users # id <User Name> # view specified user information # last # view User Logon logs # cut-d: -f1/etc/passwd # view all users in the system # cut-d:-f1/etc/group # view all groups in the system # crontab-l # view the scheduled tasks of the current user
Service:
# Chkconfig-list # list all system services # chkconfig-list | grep on # list all started system services
Program:
# Rpm-qa # view all installed software packages