Practical Bash Scripting On Linux and Mac OSX

Master bash scripting on Linux and macOS by learning shell fundamentals, commands, redirections, pipes, process management, signals, and basic networking concepts.

Explore the Linux and Unix file system hierarchy from the root to key directories such as /bin, /usr, /home, /lib, and /proc, and learn mounting concepts.

Explore multitasking and multi-user concepts in Linux, showing how the kernel scheduler switches between processes to run concurrently, while isolating each user's context and using synchronization like locks and semaphores.

Learn how environment variables, such as PATH and library paths, guide binary discovery on Linux and Mac, and master exporting, unsetting, and persisting them across shells and child processes.

discover how cp copies files and blocks and how mv moves or renames items. understand inode as a reference to data blocks and how clear resets the terminal.

Use who to see which users are logged in. Learn how whoami shows your current user, and how which and locate clarify command paths and file searches.

Master vi editor basics: open files, edit, save, quit with standard or forced commands; split windows, cycle between panes, and move with h j k l, undo edits.

Learn how chmod controls user, group, and other permissions using read, write, and execute bits. Explore numeric permissions (4,2,1) and the risks of setting 777.

Learn to change file ownership and group with chown and chgrp, apply permissions recursively with chmod, and verify users and groups using getent.

Learn to use the top command and the ps command to view system uptime, load, memory, and per-process details, and use batch mode for scripting.

Master bash pipes and redirection, including exec usage, redirecting file descriptors, and tee to display and log output, with examples involving less, wc, and find.

Explore wild cards in bash, using question marks and asterisks to match single or multiple characters, brackets and ranges for patterns, with backslash escaping to treat literals.

Explore the find command to locate files and folders starting from the current directory, using -name and case-insensitive searches, wildcards, depth limits, and exclusions.

Explore practical examples of the find command: search by name, extension, and type, use case-insensitive matching, limit depth, and locate hidden files in Linux and Mac OSX.

Learn to use grep for cross-file searches, compare basic and extended regular expressions, and apply options such as -F, -n, and -r for fixed strings, line numbers, and recursive search.

Master grep to search across files and folders with case-insensitive patterns and wildcards. Learn to invert matches, display filenames, and pipe results to awk for symbol extraction.

Explore the components of a shell script, learn how it runs as an interpreted language, and master debugging with bash, comments, variables, functions, arguments, and exit status.

Explore how while loops control bash scripts by evaluating conditions, using sleep to pace execution, and incrementing counters. Learn infinite loops with while true and one-liner usage.

Explore the bash for loop and its variants, from simple lists to numeric ranges and c-like syntax, including infinite loops and sequence iterations.

Learn to capture user input in bash with the read command, which blocks until enter and stores data in a variable or array, using -n and -a options.

Learn to open a file and read it line by line in bash with while read, parsing lines, counting them, and performing basic operations while avoiding subshell variable loss.

Explore how the shell reports exit status, distinguish zero (success) from non-zero errors, and use the $? variable, exit codes, and handling of cases like no such file or directory.

Explore generating and using random numbers in bash scripts, including ranges like 1 to 1000, looping for multiple samples, and applying randomness to timing and file naming.

Learn trap and signal handling in bash, using functions for cleanup and signal actions, and control termination with kill, SIGINT, and exit to avoid zombie processes.

Explore trap and signal handling in bash, including capturing signals, using continue in loops, and managing sleep and kill events across bash and sh differences.

Learn how to use bash traps to restore and replace signal handlers for ctrl-c on linux and mac os x, including one-time and time-based exits with cleanup.

Learn to use cal to view calendars, date to format day, month, and year across time zones like UTC and London, and time to measure script runtime.

Explore disk usage and open file management on Linux and Mac using df, du, lsof, and netstat; read outputs in human readable format and troubleshoot open file descriptors.

Learn to use nmap for network and port scanning on Linux and Mac OS X, covering installation, basic commands, timing options, and firewall considerations.

Learn to use ssh for terminal access from mac os x to linux machine, specify port 22, username, and IP, scp with sshpass for file transfer, and enable x11 forwarding.

Learn to use tcpdump to capture and inspect network traffic across Linux, macOS, and Windows. Filter by interface and port, save pcap files, and interpret protocol data for diagnostics.