All of these commands give you command-line option help by typing: [command] --help Don't use the brackets, they are there to denote the command. Some of these commands are in optional packages. Follow the prompt. Many of these commands will return a permissions error unless you precede it with 'sudo'. (Without the quotes, dear.)
Get more detailed help by typing: man [command]
Use the semicolon to run one after another until something goes wrong. [command 1] ; [command 2] Use double-ampersands (logical AND) to run next only when previous exits normally. [command 1] && [command 2] Use double pipe (logical OR) to run next only when previous exits with error. [command 1] || [command 2] Use both to do [if command 1 good, [command 2], else [command 3]] [command 1] && [command 2] || [command 3]
ls - list files lspci - lists recognized pci bus stuff lshw - lists hardware drivers and stuff uname -a - displays the linux kernel version and hostname lsb_release -a - shows the distribution version
arp - list active computers on network.
ip addr - show current Ethernet interfaces and IP address.
netstat - shows contents of /proc/net files.
tcpdump - inspect packets
ping - finds if remote computer is up
hostname - displays or changes my computer's hostname
traceroute - traces route from my computer to remote
tracepath - similar to traceroute
findsmb - find Windows shares
ifconfig - lists all interfaces running
ip - has pretty much replaced ifconfig. ip addr shows interface addressing
ifup - bring an interface up - ifup wlan0 (this is NOT: if up. It's "eye-eff" up. if for "interface".
ifdown - take an interface down
route - displays or modifies routing table
rfkill - overrides wireless status
ex: rfkill unblock wlan
sudo rfkill block wifi - to turn off wifi
sudo rfkill block bluetooth - to turn off bluetooth
iwconfig - displays wireless network interface information
Provides signal strength info
ex: iwconfig wlan0 essid NETWORK_ID key WIRELESS_KEY
iwlist - show info about WiFi interface.
ex: iwlist wlan0 scanning == show me everything around me
iwlist wlan0 freq == show me what bands work on this device
dhclient - get an IP address via dhcp
ex: sudo dhclient wlan0
host - provides basic info about an Internet host
dig - part of dnsutils package. "$ dig drgerg.com ns2.digitalocean.com NS"
whois - find the domain owner's information
wget - download file from website
curl - like wget with more - "curl -T
tmux - split one terminal into multiple terminals in one screen. CTRL-B % splits. CTRL-B ? for help. nmap - very powerful net scanner. ex: sudo nmap -sn 192.168.1.0/24 to list all devices on network. ex: sudo nmap -A 192.168.1.4 to show a lot of info on one device. links - text mode browser with mouse support pdftk - burst, combine, password protect pdf docs rl - randomize-lines, input text file, randomize the lines, output to file bless - GUI hex editor nvtop - NVIDIA card monitor. Must be running nvidia drivers. smartctl - See "DISK SPECIFIC". imagemagik - work with image files convert example.png -resize 1024 example.png (note only 1 dash in option) - - resizes using only width, keeping ratio, to same filename. - - (my personal scaling suffixes for Github: -s is 640. -vs is 320.)
ssh - logs you in to the remote computer terminal. Default port is 22. Other ports more secure. ex: ssh -p[port] user@remoteHost scp - Secure Copy. Copies files to or from remote over ssh. ex: scp -P[port] user@remoteHost:/path/to/file.ext /path/to/local/folder/ NOTE: reverse the order of the last two parts to copy a local file to a remote folder. ssh-keygen - generates a public/private key pair for you to use in automated authentication ssh-copy-id - authorizes you on a remote computer so you don't have to provide a password every time. NOTE: you have to already have access to the remote for this to work. You'll be prompted for your login password during the process. ssh-copy-id -i ~/.ssh/[key] -p [port] user@host.address As a general rule: on your local device, ensure permissions are: 0600 on the private key (owner read/write only, group & other NO) 0644 on the public key (owner read/write, group & other read only)
df - free disk space "df -h" produces short numbers du - disk usage - "du -s /500gig" for summary lsof - list open files: -i shows files open through network sudo update-grub - re-reads drives and configures boot loader dd - VERY powerful disk utility. Create disk images and more. ex: dd if=/dev/sda2 of=mysda2part creates a disk image named mysda2part. Check network speed using a combination of dd and ssh: dd if=/dev/zero bs=1M count=1000 | ssh -p[port] user@remote-computer 'dd of=/dev/null' blkid - get the UUID for a disk. Use 'sudo blkid /dev/part' smartctl - part of smartmontools. See SMART data for a drive. 'sudo smartctl --all /dev/sda'
adduser - add a new user. Also adds users to groups. addgroup - add a new group. mkpasswd - use to encrpyt passwords (read before using) passwd - change user password. SU can change forgotten passwords. usermod - make changes to user accounts. groups - shows what groups a user belongs to.
find - Find a file. "sudo find / -name Adafruit*" cat - Hugely useful program. Takes stuff in and puts it out. nc - netcat - does the same across a network connection. cp - copy files. 'cp -ar source dest' = recursive, keeps stamps. rsync - heavy-duty network file sync. dd - create disk images and more. chmod - change permissions flags on files and directories chown - change the owner and group of a file or folder chgrp - change only the group of a file or folder
Open text editor ex: sudo nano my_script opens the nano text editor under root permissions First line must be: #! /bin/bash Then put your command line commands one at a time like a DOS batch file. Save. sudo chmod 774 my_script changes the permissions flags to allow execution by owner:group in this case owner:group is root:root
Ghostscript (gs) is a powerful tool for converting graphics files. Example: Convert .ps file of a certain size to a .pdf file. gs -q -sDEVICE=pdfwrite -g5584x5024 -r300 -sOutputFile=UNT_racks.pdf UNT_300_port.ps
Last edited 04/08/2024 Four7zero.com is here courtesy of drgerg.com