Basic Linux/Unix Commands

System

 
# 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
 

Resources

# Free-M # view memory usage and swap zone usage # DF-h # view usage of each partition # Du-SH <Directory Name> # view the size of a specified directory # grep memtotal/proc /meminfo # view the 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