# Show free and used space on mounted filesystemsdf -h# Show free and used inodes on mounted filesystemsdf -i# Display disks partitions sizes and typesfdisk -l# Display disk usage for all files and directories in human readable formatdu -ah# Display total disk usage off the current directorydu -sh&n

# Secure copy file.txt to the /tmp folder on serverscp file.txt server:/tmp# Copy *.html files from server to the local /tmp folder.scp server:/var/www/*.html /tmp# Copy all files and directories recursively from server to the current system's /tmp folder.scp -r server:/var/www /tmp# Synchronize /ho

# Connect to host as your local username.ssh host# Connect to host as userssh user@host# Connect to host using portssh -p port user@host

# Search for pattern in filegrep pattern file# Search recursively for pattern in directorygrep -r pattern directory# Find files and directories by namelocate name# Find files in /home/john that start with "prefix".find /home/john -name 'prefix*'# Find files larger than 100MB in /homefind /home -size

# Search for a package by keyword.yum search keyword# Install package.yum install package# Display description and summary information about package.yum info package# Install package from local file named package.rpmrpm -i package.rpm# Remove/uninstall package.yum remove package# Install software fr

# Create tar named archive.tar containing directory.tar cf archive.tar directory# Extract the contents from archive.tar.tar xf archive.tar# Create a gzip compressed tar file name archive.tar.gz.tar czf archive.tar.gz directory# Extract a gzip compressed tar file.tar xzf archive.tar.gz# Create a tar 

# Display all network interfaces and IP addressip a# Display eth0 address and detailsip addr show dev eth0# Query or control network driver and hardware settingsethtool eth0# Send ICMP echo request to hostping host# Display whois information for domainwhois domain# Display DNS information for domain

PERMISSION      EXAMPLE        U   G   W       rwx rwx rwx     chmod 777 filename       rwx rwx r-x     chmod 775 filename       rwx r-x r-x     chmod 755 filename&n