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.

Learn how shell scripts run as interpreted programs, explore bash basics, and master variables, functions, and debugging techniques such as set -x and syntax checks.

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.

Explore common Linux and Mac commands to list files, use long and hidden file views, and navigate directories with ls options, permissions, and path concepts like root and working directory.

Learn common Linux commands like cat and ls, create and view files with redirection and piping, and safely delete recursively with rm -rf.

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.

Learn to use cal for calendars and the date command for time, formatting, and time zones such as UTC and London, including setting system dates.

Learn the basics of Vim, install Vim, switch between insert and command modes, edit text with delete, yank, and paste, search and replace, and navigate by lines and marks.

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.

Manage background and foreground jobs in bash using no hangup, bring a job to the foreground by its number, kill it, and redirect output to a file.

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.

Describe how Linux and Unix use file descriptors for standard input, output, and error, and how redirection with >, >>, and dev/null directs and handles command output.

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.

Explore advanced file searches with the find command, filtering by name, extension, permissions (including sticky bit and 777), owner, and using superuser privileges carefully.

Learn to use the find command on Linux to locate files by modified, accessed times and by size, search by name patterns, and safely pipe results to xargs for execution.

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.

Learn to search files with grep using patterns and regex, use word boundaries for exact matches, hide filenames with -H, perform case-insensitive searches -i, and show line numbers -n.

Learn how to use grep to search for keywords across files with patterns, fixed strings (-F), and pattern files (-f), show matches with context (-A/-B) and pipe input.

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.

Learn how the bash until loop runs while the condition is false and exits when it becomes true, with examples using false conditions and a countdown.

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

Explore bash scripting with if statements, conditional expressions, and else if constructs, learn how true conditions execute statements, and use numeric and string comparisons in shell code.

Learn to use bash test conditions to check file existence and type—block devices, character devices, regular files, and directories—and apply POSIX compliant test expressions.

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.

Explore the case statement in bash, a switch-like construct that evaluates a variable against patterns, uses default handling, and requires double semicolons to exit each case inside a while loop.

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.

Explore bash arrays: declare and index elements, create lists with spaces, access by index, iterate with for loops and read input, and manipulate strings and numbers in practical scripting.

Learn to use here documents for multi-line comments and automating bash scripts with a start token at the line start and an end token, noting security.

Explores trap and signal in Linux as interprocess communication; explains signals, kill, trap, and SIGINT, and how to handle or trap signals in programs.

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.

Explore how signal handlers manage exit signals, traps, and interruptions in a bash script, with examples of sleep, log cleanup, and cleanup behavior.

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.

Master dd and od to copy files, create sparse files, or fill disks with /dev/zero, and inspect data in hex or ascii, using block size and count to control size.

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.

Explore how Linux commands dmidecode, lscpu, and lspci reveal BIOS, processor, and hardware details via SMBIOS and DMI, with examples on virtual machines and real hardware.

Attach a new disk in a virtual or physical environment, partition the drive, create a partition table, format in Linux or macOS environments, and mount the partition for use.

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.