How to view logs in linux (Common commands)

How to view logs in linux (Common commands)

Cat

Tail-f

Japanese text description

 
 

  
  
/Var/log/message information and error logs after the system is started. It is one of the most common logs in Red Hat Linux.
  
  
/Var/log/secure security-related log information
  
  
/Var/log/maillog and mail-related log information
  
  
/Var/log/cron log information related to scheduled tasks
  
  
/Var/log/spooler logs related to UCP and news Devices
  
  
/Var/log/boot. log daemon starts and stops related log messages
 
 

System:

 
 

  
  
# Uname-a # view kernel/operating system/CPU Information
  
  
# Cat/etc/issue
  
  
# Cat/etc/redhat-release # view the operating system version
  
  
# Cat/proc/cpuinfo # view CPU Information
  
  
# Hostname # view the computer name
  
  
# Lspci-TV # list all PCI devices
  
  
# Lsusb-TV # list all USB devices
  
  
# Lsmod # list loaded Kernel Modules
  
  
# Env # view environment variables
 
 

Resource:

 
 

  
  
# Free-m # view memory usage and swap zone usage
  
  
# Df-h # view the usage of each partition
  
  
# Du-sh <Directory Name> # 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 system running time, number of users, and load
  
  
# Cat/proc/loadavg # view 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 parameters (only applicable 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 the route 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 # display Process status in real time in another article)
 
 

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