cd ../.. // Usecase: Move up two levels
Ctrl + L // Clear screen by scrolling down
touch
Ex. touch [OPTION]... File...
[OPTION] = optional
File... = required filenames
creating a new file using CLI provided it doesn't exist. In case file exists, it will update the access & modification time to the current time. A File argument that does not exist is created empty.
touch : extension is mandatory, else generic file will be created.
touch ../dog.txt : create a file one level above in parent directory
touch ~/cat.txt : create a file in home directory.
Ex. touch file{1..100}.txt
Ex. touch app.{html,css,js}
Ex. ls -l : long format
Ex. mkdir {images,css,src,templates,scripts}
NOTE = Only one caveat here: just ensure that there are no spaces between the words inside the braces.
pwd:
print working directory
Output: Full path of the current directory you are in. Helps in determining current location within the file system hierarchy.
pwd : shows the full path of the current working directory
pwd -L : (Default), prints the logical path, meaning it shows the path as it appears in the file system
pwd -P : prints the physical path, which resolves all symbolic links to show the actual path on the disk.
dirname:
to strip the last component from a given file path, effectively providing the directory path that contains the file or directory specified.
Usage: Useful for extracting the directory name from a full file path, which can be helpful in scripts and file manipulation tasks.
Ex: dirname /home/user/documents/file.txt
Output: /home/user/documents
Strips file.txt from the path, leaving /home/user/documents
rm & rmdir:
rm -r //will delete mydirectory and everything inside it.
rmdir // will delete mydirectory only if it is empty.
netstat
"netstat -an | grep ESTABLISHED" = Shows all established connections.
"netstat -antp (Linux) or netstat -an -o" (Win) provides additional details, including the process ID (PID) associated with the connection.
Ctrl + R = for reverse search
Ctrl + L = clear the screen
Ctrl + D = exit terminal
curl ifconfig.me = See your public IP
who: (show who is logged on)
who -a: All available information.
who -q: Number of logged-on users.
Flags: [Case-sensitive]
-a OR --all
-i OR --interactive
-l OR long format
-m OR --message
-q OR --quiet
-v OR --version
-w OR --watch
-y OR --yes
-D OR --save-dev
-L OR --logical
-P OR --physical
File and Directory Management
find || locate || ln || rsync || scp || rclone || tree || fdupes || file || basename || split || paste || md5sum || comm || sha256sum || iconv || dos2unix || unix2dos || tac || nl || pr || yes || rev || watch || env || export || alias || unalias || which || whereis || apropos
Text Processing
awk || sed || sort || uniq || cut || tr || wc || diff || cmp
Process Management
bg/fg || jobs || nohup || htop || nice/renice
File content
cat || less || head || tail || grep || nano/vim || tee ||
Permissions
chmod || chown
System Information, Monitoring & Performance
whoami || uname || df || du || top || ps || kill || killall || uptime || iotop || vmstat || iostat || sar || mpstat || lsof || lsb_release || dstat || ps || pgrep || time ||
System & User Management
useradd / userdel || usermod || passwd || sudo || cron || dmesg || journalctl || systemctl
Networking & Security
ping || ifconfig / ip addr || wget || curl || ss || iptables || scp || ssh || telnet || dig || nc [netstat] || fail2ban || ufw || openssl || gpg || nslookup ||
Archiving & Compression
tar || zip / unzip
Package Management
apt-get [debian based] || yum / dnf [red-hat or cent-os based] || snap || brew [Mac-OS & Linux]
Development Tools
gcc || make || git || docker || virtualenv || npm || pip || python || node || javac || docker || kubernetes / kubectl || vagrant || terraform
Disk & File Management
mount / unmount || fsck || dd || fdisk / parted || mkfs || resize2fs || cryptsetup || btrfs
Scripting & Automation
alias || xargs || exec || cron
Debugging, Tshooting, Diagnostics & Logs
strace || ltrace || tcpdump || gdb || nmap || traceroute || who || last || lshw || lsblk || blkid || fdisk || hdparm || ethtool || iwconfig || nmcli || host || ipcalc || mtr || firewalld || route || whois || free || nmon