Linux Commands For Developers


  • Linux Help

    1. HARDWARE INFORMATION

    #Display messages in kernel ring buffer
    dmesg
    
    #Display CPU information.
    cat /proc/cpuinfo
    
    #Display memory information.
    cat /proc/meminfo
    
    #Display free and used memory ( -h for human readable, -m for MB, -g for GB.).
    free -h
    
    #Display PCI devices.
    lspci -tv
    
    #Display USB devices.
    lsusb -tv
    
    #Display DMI/SMBIOS (hardware info) from the BIOS.
    dmidecode
    
    #Show info about disk sda.
    hdparm -i /dev/sda
    
    #Perform a read speed test on disk sda.
    hdparm -tT /dev/sda
    
    #Test for unreadable blocks on disk sda.
    badblocks -s /dev/sda
    

    2. SYSTEM INFORMATION

    #Display Linux system information.
    uname -a
    
    #Display kernel release information.
    uname -r
    
    #Show which version of redhat installed.
    cat /etc/redhat-release
    
    #Show how long the system has been running + load.
    uptime
    
    #Show system host name.
    hostname
    
    #Display the IP addresses of the host.
    hostname -I
    
    #Show system reboot history.
    last reboot
    
    #Show the current date and time.
    date
    
    #Show this month's calendar.
    cal
    
    #Display who is online.
    w
    
    #Who you are logged in as
    whoami
    

    3. USER INFORMATION AND MANAGEMENT

    #Display the user and group ids of your current user.
    id
    
    #Display the last users who have logged onto the system.
    last
    
    #Show who is logged into the system.
    who
    
    #how who is logged in and what they are doing.
    w
    
    #Create a group named "test".
    groupadd test
    
    #Create an account named john, with a comment of "John Smith" and create the user's home directory.
    useradd -c "John Smith" -m john
    
    #Delete the john account.
    userdel john
    
    #Add the john account to the sales group.
    usermod -aG sales john
    

    4. FILE AND DIRECTORY COMMANDS

    #List all files in a long listing (detailed) format.
    ls -al
    
    #Display the present working directory.
    pwd
    
    #Create a directory.
    mkdir directory
    
    #Remove (delete) file.
    rm file
    
    #Remove the directory and its contents recursively.
    rm -r directory
    
    #Force removal of file without prompting for confirmation.
    rm -f file
    
    #Forcefully remove directory recursively.
    rm -rf directory
    
    #Copy file1 to file2.
    cp file1 file2
    
    #Copy source_directory recursively to destination. If destination exists, copy source_directory into destination, otherwise create destination with the contents of source_directory.
    cp -r source_directory destination
    
    #Rename or move file1 to file2. If file2 is an existing directory, move file1 into directory file2.
    mv file1 file2
    
    #Create symbolic link to linkname.
    ln -s /path/to/file linkname
    
    #Create an empty file or update the access and modification times of file.
    touch file
    
    #View the contents of file.
    cat file
    
    #Browse through a text file.
    less file
    
    #Display the first 10 lines of file.
    head file
    
    #Display the last 10 lines of file.
    tail file
    
    #Display the last 10 lines of file and "follow" the file as it grows.
    tail -f file
    

    5. FILE PERMISSIONS
    0_1543122821558_linux-permissions-chart.png

    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
    rw- rw- r--     chmod 664 filename
    rw- r-- r--     chmod 644 filename
    

    6. PROCESS MANAGEMENT

    #Display your currently running processes.
    ps
    
    #Display all the currently running processes on the system.
    ps -ef
    
    #Display process information for processname.
    ps -ef | grep processname
    
    #Display and manage the top processes.
    top
    
    #Interactive process viewer (top alternative).
    htop
    
    #Kill process with process ID of pid.
    kill pid
    
    #Kill all processes named processname.
    killall processname
    
    #Start program in the background.
    program &
    
    #Display stopped or background jobs.
    bg
    
    #Brings the most recent background job to foreground.
    fg
    
    #Brings job n to the foreground.
    fg n
    

    7. PERFORMANCE MONITORING AND STATISTICS

    #Display and manage the top processes.
    top
    
    #Interactive process viewer (top alternative).
    htop
    
    #Display processor related statistics.
    mpstat 1
    
    #Display virtual memory statistics.
    vmstat 1
    
    #Display I/O statistics.
    iostat 1
    
    #Display the last 100 syslog messages  (Use /var/log/syslog for Debian based systems.).
    tail 100 /var/log/messages
    
    #Capture and display all packets on interface eth0.
    tcpdump -i eth0
    
    #Monitor all traffic on port 80 ( HTTP ).
    tcpdump -i eth0 'port 80'
    
    #List all open files on the system.
    lsof
    
    #List files opened by user.
    lsof -u user
    
    #Display free and used memory ( -h for human readable, -m for MB, -g for GB.).
    free -h
    
    #Execute "df -h", showing periodic updates.
    watch df -h
    

    8. NETWORKING

    #Display all network interfaces and ip address.
    ifconfig -a
    
    #Display eth0 address and details.
    ifconfig eth0
    
    #Query or control network driver and hardware settings.
    ethtool eth0
    
    #Send ICMP echo request to host.
    ping host
    
    #Display whois information for domain.
    whois domain
    
    #Display DNS information for domain.
    dig domain
    
    #Reverse lookup of IP_ADDRESS.
    dig -x IP_ADDRESS
    
    #Display DNS ip address for domain.
    host domain
    
    #Display the network address of the host name.
    hostname -i
    
    #Display all local ip addresses.
    hostname -I
    
    #Download http://domain.com/file.
    wget http://domain.com/file
    
    #Display listening tcp and udp ports and corresponding programs.
    netstat -nutlp
    

    9. ARCHIVES (TAR FILES)

    #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 file with bzip2 compression.
    tar cjf archive.tar.bz2 directory
    
    #Extract a bzip2 compressed tar file.
    tar xjf archive.tar.bz2
    

    10. SEARCH

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

    11. SSH LOGINS

    #Connect to host as your local username.
    ssh host
    
    #Connect to host as user.
    ssh [email protected]
    
    #Connect to host using port.
    ssh -p port [email protected]
    

    12. FILE TRANSFERS

    #Secure copy file.txt to the /tmp folder on server.
    scp 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 /home to /backups/home.
    rsync -a /home /backups/
    
    #Synchronize files/directories between the local and remote system with compression enabled.
    rsync -avz /home server:/backups/
    

    13. DISK USAGE

    #Show free and used space on mounted filesystems.
    df -h
    
    #Show free and used inodes on mounted filesystems.
    df -i
    
    #Display disks partitions sizes and types.
    fdisk -l
    
    #Display disk usage for all files and directories in human readable format.
    du -ah
    
    #Display total disk usage off the current directory.
    du -sh
    

    14. DIRECTORY NAVIGATION

    #To go up one level of the directory tree.  (Change into the parent directory.).
    cd ..
    
    #Go to the $HOME directory.
    cd
    
    #Change to the /etc directory.
    cd /etc
    

    @Linux-Help


  • Linux Help

    Installing packages commands posting soon.



  • Thanks ❤


  • Linux Help

    @Danuva welcome bro


  • Node.js

    nice post ♥



  • Great work. 👍Hope to see more from you.


  • Linux Help

    @dinlinux Yah, i'll post everything about linux



  • thanx ❤