100+ Linux commands that Linux Sysadmins regularly use, with explanation.

Thank you @linuxopsys.

100+ Linux commands that Linux Sysadmins regularly use, with explanation

  • cut : allows you to cut out sections of a specified file or piped data and print the result to standard output.
  • sort : used to sort files
  • uniq : used to extract uniq occurences
  • tr : utility for translating or deleting characters.
  • grep : searches a file for a pattern of characters and displays all lines that match.
  • awk : a scripting language used for text processing.
  • sed : stream editor used to perform lots of functions on files, like searching, find and replace, insertion, or deletion.
  • pstree : used to show running processes in a tree (data structure).
  • latest : displays a list of the most recently logged-in people.
  • w : display a list of the currently logged-in user sessions.
  • free : use to get a detailed report on the system’s memory usage.
  • scp : securely copy files or directories over ssh.
  • find : locates files using user-defined criteria.
  • ncdu : provides a useful and convenient way to view disk usage.
  • ip : used to show or manipulate routing, devices, and tunnels.
  • ls : list the contents of a directory.
  • df : Displays the amount of disk space used.
  • du : display a list of all the files along with their respective sizes.
  • diff : used to display differences in files by comparing line by line.
  • uptime : displays the system uptime as well as the load average.
  • top : shows a real-time view of running processes in Linux.
  • dstat : allows you to view all of your system resources instantly. All-in-one vmstat, iostat, netstat, and ifstat utility.
  • Iftop is a network traffic viewer.
  • nethogs : is a network traffic analyzer.
  • vmstat : used to obtain information about memory, system processes, paging, interrupts, block I/O, disk, and CPU scheduling.
  • htop : a process viewer and manager that is interactive.
  • iotop : is an interactive I/O viewer. Get a snapshot of storage r/w activity.
  • iostat : provides statistics on storage I/O.
  • netstat : used to show network statistics.
  • ss : ss command is a simpler and faster version of the now obsolete netstat command.
  • atop : a tool for monitoring system resources in Linux.
  • ssh : secure protocol used as the primary means of connecting to Linux servers remotely.
  • sudo : run commands with administrative privileges.
  • cd : navigate between directories.
  • touch : used to create, update a computer file or directory’s access and modification dates.
  • man : used to read system reference manuals.
  • apropos : searches manual page names and descriptions for a user-supplied keyword.
  • pwd : displays the current directory path.
  • cp : copy files and directories.
  • mv : move file or directories.
  • rm : deletes files and directories.
  • mkdir : create new directories.
  • rsync : remote file transfer and synchronization.
  • tar : is an archive utility.
  • gzip : use for compression and decompression of files.
  • b2zip : a compression utility comparable to gzip. It employs a distinct compression algorithm.
  • zip : used for file packaging and compression (archiving).
  • locate : in Linux, search for files.
  • ps : allows you to list the status of processes running on your system easily.
  • cron : execute scheduled tasks.
  • mtr : is a network diagnostic tool, a combination of ping and traceroute commands.
  • nslookup : interactively query Internet name servers (NS).
  • host : used for DNS (Domain Name System) lookup operations.
  • dig : DNS lookup tool.
  • nmcli : sused to display network device status, create, edit, activate/deactivate, and delete network connections.
  • ping : sends an ICMP ECHO REQUEST to network hosts.
  • traceroute : examine the path packets follow to reach a specific host.
  • wget : download files through HTTP, HTTPS, FTP, and FTPS.
  • curl : data transport via several network protocols. (Can handle more protocols than wget)
  • dd : used to convert and copy files.
  • fdisk : Modify the disk partition table.
  • parted : used to create and manipulate partition tables.
  • blkid : a command-line utility for finding and printing block device attributes.
  • mkfs : create a Linux file system.
  • fsck : an utility for determining the consistency of a file system.
  • nc : used for just about anything under the sun involving TCP or UDP.
  • umask : returns, or sets, the value of the system’s file mode creation mask.
  • chmod : alters the access rights of file system objects.
  • chown : alter the owner and group of a file.
  • chroot : used to change the root directory.
  • useradd : create a new user or alter the default information for a new user.
  • userdel : used to delete a user account and all associated files.
  • usermod : used to edit or change any existing user account’s properties.
  • vi is a text editor.
  • cat : displays the contents of a file.
  • tac : reverse output file contents.
  • more : show file contents one screen/page at a time.
  • less : identical to more, but with more features
  • tail : used to show the last few lines of a text file or piped data.
  • head : used to show the first few lines of a text file or piped data.
  • dmesg : displays the kernel ring’s message buffer.
  • journalctl : Tused to view systemd, kernel and journal logs.
  • kill : terminates a process.
  • killall : sends a kill signal to all instances of a specific process.
  • sleep : pauses program execution for a given amount of time.
  • wait : suspend script execution until all background jobs have been completed.
  • nohup : short for no hang up is a command in Linux systems that keep processes running even after exiting the shell or terminal.
  • screen : keep a remote server session open. (It also functions as a full-screen window manager.)
  • tmux is a terminal multiplexer.
  • passwd — Change the password of a user.
  • clear : clears the terminal’s screen.
  • env : run a command in an altered environment
  • mount : used to mount the filesystem found on a device to big tree structure(Linux filesystem) rooted at ‘/’.
    92 : umount : unmounts a previously mounted device, directory, file, or file system.
  • systemctl : used to control and manage systemd and services.
  • alias : defines an alias for the specified command.
  • at : runs a specified script or command at a set later time.
  • atq : shows jobs in the at utility queue.
  • atrm : deletes the specified job from the at utility queue.
  • bash : uses the Bourne Again Shell command language to interpret commands from standard input or a file, or to launch a subshell.
  • bc : Performs calculations via its programming language.
  • bash : uses the Bourne Again Shell command language to interpret commands from standard input or a file, or to launch a subshell.
  • bc : Performs calculations via its programming language.
  • chfn : changes the specified user account’s current information.
  • chgrp : changes the default group of the specified file or directory.
  • chmod : changes system security permissions for the specified file or directory
  • chown : changes the default owner of the specified file or directory.
  • chpasswd : reads a file of login name and password pairs and updates the passwords.
  • chsh : changes the specified user account’s default shell.
  • continue : resumes the next iteration of a for , while , select , or until loop.
  • coproc : spawns a subshell in background mode and executes the designated command or executes a coprocess.
  • env : executes the designated program in a modified environment or displays the value of all the environment variables.
    → arp – see your arp table.
    → aria2 – downloading just about everything. Torrents included.
    → arpwatch – Ethernet Activity Monitor.
    → bmon – bandwidth monitor and rate estimator.
    → bwm-ng – live network bandwidth monitor.
    → curl – transferring data with URLs.(or try httpie)
    → darkstat – captures network traffic, usage statistics.
    → dhclient – Dynamic Host Configuration Protocol Client
    → dig – query DNS servers for information.
    → dstat – replacement for vmstat, iostat, mpstat, netstat and ifstat.
    → ethtool – utility for controlling network drivers and hardware.
    → gated – gateway routing daemon.
    → host – DNS lookup utility.
    → hping – TCP/IP packet assembler/analyzer.
    → ibmonitor – shows bandwidth and total data transferred.
    → ifstat – report network interfaces bandwidth.
    → iftop – display bandwidth usage.
    → ip – a command with more features than ifconfig.
    → iperf3 – network bandwidth measurement tool.
    → iproute2 – collection of utilities for controlling TCP/IP.
    → iptables – take control of network traffic.
    → IPTraf – An IP Network Monitor.
    → iputils – set of small useful utilities for Linux networking.
    → iw – a new nl80211 based CLI configuration utility → for wireless devices.
    → jwhois (whois) – client for the whois service.
    → lsof -i – reveal information about your network sockets.
    → mtr – network diagnostic tool.
    → net-tools – utilities include: arp, hostname, ifconfig, netstat, rarp, route, plipconfig, slattach, mii-tool, iptunnel and ipmaddr.
    → ncat – improved re-implementation of the venerable netcat.
    → netcat – networking utility for reading/writing network connections.
    → nethogs – a small ‘net top’ tool.
    → Netperf – Network bandwidth Testing.
    → netplan – Netplan is a utility for easily configuring
    → networking on a linux system.
    → netsniff-ng – Swiss army knife for daily Linux network plumbing.
    → netwatch – monitoring Network Connections.
    → ngrep – grep applied to the network layer.
    → nload – display network usage.
    → nmap – network discovery and security auditing.
    → nmcli – a command-line tool for controlling NetworkManager and reporting network status.
    → nmtui – provides a text interface to configure networking by controlling NetworkManager.
    → nslookup – query Internet name servers interactively.
    → ping – send icmp echo_request to network hosts to test connectivity.
    → route – show / manipulate the IP routing table.
    → slurm – network load monitor.
    → snort – Network Intrusion Detection and Prevention System.
    → smokeping – keeps track of your network latency.
    → socat – establishes two bidirectional byte streams and transfers data between them.
    → speedometer – Measure and display the rate of data across a network.
    → speedtest-cli – test internet bandwidth using http://speedtest.net
    → ss – utility to investigate sockets.
    → ssh – secure system administration and file transfers over insecure networks.
    → tcpdump – command-line packet analyzer.
    → tcptrack – Displays information about tcp connections on a network interface.
    → telnet – user interface to the TELNET protocol.
    → tracepath – very similar function to traceroute.
    → traceroute – print the route packets trace to network host.
    → vnStat – network traffic monitor.
    → websocat – Connection forwarder from/to web sockets to/from usual sockets, in style of socat.
    → wget – retrieving files using HTTP, HTTPS, FTP and FTPS.
    → Wireless Tools for Linux – includes iwconfig, iwlist, iwspy, iwpriv and ifrename.
    → Wireshark – network protocol analyzer.
Advertisement

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s