Linux Commands
Command references for core Linux tools, syntax, examples, and practical one-liners.
reboot Command in Linux: Restart with systemctl and shutdown -r
Three commands cover common Linux reboot scenarios: reboot for an immediate restart, systemctl reboot for the systemd path, and shutdown -r for scheduled restarts with user notifications.
Linux Kill Process: Stop Processes by PID or Name
Stop stuck programs in Linux with kill, killall, pkill, and xkill. Find the PID, send SIGTERM first, and use SIGKILL only when the process refuses to exit.
df Command in Linux: Check Disk Space Usage
Check disk space usage in Linux with the df command. Human-readable and fixed block sizes, filesystem types, inode usage, custom output fields, and df vs du.
How to Add a Directory to PATH in Linux
Add a directory to the PATH variable in Linux, temporarily or permanently, covering ~/.local/bin, custom binaries, and system-wide changes for all users.
traceroute Command in Linux
Trace the path packets take to a host, read every field of the traceroute output, decode hops that show asterisks or !X, and map Windows tracert flags to Linux.
Grep Regex: Regular Expressions Syntax and Examples
Use grep regex to match text patterns. Examples for anchors, character classes, quantifiers, alternation, grouping, and PCRE lookarounds.
How to Run Linux Commands in the Background
Run Linux commands in the background using &, disown, and nohup. This guide explains how to start background processes, move foreground jobs to the background, and keep processes running after the shell exits.
Regular Expressions Explained: How Regex Patterns Work
Regular expressions explained from the ground up: how anchors, character classes, quantifiers, and groups build patterns that work in grep, sed, and awk.
How to Create a File in Linux
Create a file in Linux from the command line with touch, redirection, cat, echo, printf, or a heredoc, and build large test files with fallocate, truncate, and dd.
How to Mount ISO File on Linux
Mount an ISO file on Linux with the mount command and a loop device, attach it as a regular user with udisksctl, or extract its contents without mounting. Covers desktop file managers, other disk image formats, and fstab entries.
parted Command in Linux: Manage Disk Partitions
Use the parted command to inspect disks, create GPT partition tables, add aligned partitions, resize boundaries, and remove partitions safely on Linux.
Sudo Command in Linux: Run Commands as Root
The sudo command runs programs as root or another user. This guide covers sudoers setup, root shells, sudoedit, credential caching, and common sudo options.
Linux cp Command: Copy Files and Directories
The cp command copies files and directories in Linux. This guide covers recursive and archive copies, copying directory contents, overwrite control, and attributes.
How to Use sed to Find and Replace Strings in Files
Replace strings in files with sed: run sed -i 's/old/new/g' file. Covers global, case-insensitive, word-boundary, regex, line-range, and recursive replace.
Bash Best Practices: Writing Safer, Cleaner Scripts
Practical Bash best practices for writing safer and more predictable scripts, covering strict mode, quoting, error handling, and everyday patterns.
How to List Groups in Linux
Find which groups a user belongs to in Linux using the groups, id, and getent commands. Includes how to list all groups and group members on the system.
How to Remove a Symbolic Link (Symlink) in Linux
Remove symbolic links in Linux with rm, unlink, or find. Clean up broken symlinks and avoid the trailing-slash trap that can remove target directory contents.
sleep Command in Linux: Pause a Bash Script
How to use the sleep command in bash to pause script execution. Examples cover seconds, minutes, sleep infinity, retry loops, countdowns, and background sleeps.
Tar Command in Linux: Create and Extract Archives with Examples
Create, extract, list, and compress tar archives in Linux. Examples for gzip, bzip2, xz, and zstd, plus excluding files, wildcard extraction, and stripping path components.
awk Command in Linux: Syntax, Patterns, and Examples
Use awk to extract columns, filter records, and build reports from the command line, with practical examples of patterns, built-in variables, functions, and arrays.
