Linux Commands
Command references for core Linux tools, syntax, examples, and practical one-liners.
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.
Linux basename Command: Get File Name from Path in Bash
Get just the file name from a full path in Bash. This guide covers basename options, suffix stripping, and how it compares to parameter expansion.
echo Command in Linux: Print Text and Variables
Print text, variables, script arguments, and exit codes with echo in Linux, plus escape sequences, colored output, and the quoting pitfalls to avoid.
Grep Command in Linux with Examples
The grep command searches files for text patterns. Quick examples for case-insensitive, recursive, whole-word, regex, and context-line searches.
Grep Multiple Patterns: Match Strings, Words, and Regex
Search for multiple patterns or strings at once with grep using the -e flag, fixed-string matching, alternation, and pattern files.
Grep Exclude: Patterns, Files, and Directories
Use grep to exclude patterns, files, and directories from search results. Examples for --invert-match, --exclude, --exclude-dir, and --include.
last Command in Linux: Check Login History
Use the last command in Linux to check login history, filter sessions by user or date, and audit access. Covers lastb, lastlog, and the wtmpdb replacement.
How to Use wget in Linux with Examples
Practical wget examples for downloading files, resuming transfers, limiting bandwidth, mirroring websites, and handling authentication on Linux.
How to List Users in Linux
List all users in Linux with getent passwd, lslogins, or /etc/passwd. Filter human users by UID, check group membership, and see who is logged in.
