Bash Shell Scripting: Crash Course For Beginners

Redirect command output to files using > and >>, replacing or appending content, and combine multiple commands or file contents with cat for practical text management.

Learn to use the pipe command to pass a command's output as input to another via temporary file. Combine commands with piping to tail and sort, redirecting to a file.

Learn how to use grep to search inside files, handle case sensitivity with -i, and combine commands with pipes like ls | grep, plus exclude matches with -v.

Change file ownership using sudo and the change ownership command, assigning to a user such as MacBook. Change groups with the change group command, including recursive ownership of folders.

Learn how to change ownership and permissions for folders using sudo and recursive options, applying the ownership change to MacBook with -R, changing the group to group_guest, and removing folders.

Assign values to variables, access them with dollar signs or braces, and echo results while avoiding spaces; unset variables and explore environment variables like user, home, and path.

Learn how to capture command output into variables using the dollar sign expansion and command substitution with parentheses, and compare it to backticks for Bash scripting.

Use read to assign input to a variable like my_value and display it with echo, then use -p prompts and -s hidden input for passwords in bash.

Create and rename files, restrict execution to the owner with chmod, and read user input to name and touch files interactively. Explore command substitution versus stored command execution using date.

Learn to create shell scripts by combining commands, using variables, and implementing if-else and loops to automate copying files into multiple named folders.

Learn to execute an executable file by specifying its location and name, not using dot slash as a command.

Create your first bash script by touching a file and adding a shebang to /bin/bash. Write simple commands like echo and pwd, then chmod +x and run it.

Choose the right shell script extension and editor; learn to open and edit scripts with tools like Sublime Text and Vim, and use read to capture user input.

Learn to run scripts anywhere by adding your script folder to the path variable in bash. The lesson covers exporting path, editing dot profile, and verifying with commands like python3.

Open files in bash scripts by using variables, prompting for a path, reading it into a variable, and launching with xdg-open or open on different systems.

Learn to write a bash script that creates one.txt and two.txt, writes the long listing of the current directory into one.txt, and renames it with a user-provided prefix.

Create a script that generates another script, including adding a shebang, comments, and making it executable, then run and verify the nested script.

Explore how bash if conditions control flow by evaluating numeric comparisons with -eq, -ne, -gt, -lt, -ge, and -le. When true, commands execute before continuing; when false, they are skipped.

Master string comparisons in bash by using if statements to test equality and inequality, handle case sensitivity, and reveal a file name when the password matches, else for incorrect input.

Learn to test file conditions in bash using if-then, check existence (-e), nonexistence (!), directories (-D), readability (-R), writability (-W), executability (-x), and emptiness (-s).

Learn to write Bash for loops that repeat code, using numeric ranges, custom values, and break conditions. Apply looping to files and access loop variables inside the block.

Understand how the while loop operates in bash scripting, repeating while a condition holds and increasing a number by four until the number exceeds 15, with caution against infinite loops.

Learn to use the bash case statement to drive menu-driven scripts, matching user input with patterns, ranges, and strings, and provide a none-of-the-above default.

Understand exit status in Linux commands, where zero means success and non-zero signals errors; use $? to capture it, and consult man pages for specifics, including grep's codes.

Define and reuse code with functions in shell scripting to run the same block with inputs. Use $1 and $2 and return values, zero or non-zero, to control flow.

Create a Bash script that searches all files in a folder for a hot word, copies matches to a new folder, and records line numbers; later, recursively search subfolders.

Divide a big problem into smaller parts, loop through folder items, filter regular files, handle spaces in filenames, search with grep -n, apply case-insensitive matching, and copy files when found.

Learn to use grep to decide whether to copy a file inside a loop, storing results in variables, and testing for emptiness with -z to drive conditional actions in bash.

Master recursive folder search in bash with the find command and -type d, using a for loop to scan every file for a target word across all subfolders.

Learn to build a recursive bash script with nested loops that traverses all folders and files, printing each file and using -F to process only files.

Implement a loop to search for files containing the hot word, copy them into a folder with the line number, and use base name to extract the filename.

Master Bash shell scripting by using for loops, if-else, strings, files, variables, and comments to solve real-world problems, and learn via tweaks, teaching, and StackOverflow.