Appdev

• Version Control System (VCS) is a software tool that helps track and manage changes to files and code over time
• VCS provides a systematic way to keep track of different versions of files, collaborate with others, and maintain a history of changes made to a project
• Key features of a VCS include:

  • Version Tracking: keeps track of changes made to files over time, allowing you to see the history of modifications, who made them, and when they were made
  • Collaboration: Multiple developers can work on the same project simultaneously, with changes tracked, merged, and managed to avoid conflicts
  • Branching and Merging: Developers can create separate branches of the codebase to work on specific features or fixes, later merging them back into the main codebase
  • Revert to Previous Versions: Easily revert back to a previous version of the code if needed
  • Conflict Resolution: Tools provided to help resolve conflicts and merge changes
  • Historical Documentation: Maintains a chronological record of changes, useful for auditing, troubleshooting, and understanding project evolution
  • Backup and Disaster Recovery: Acts as a form of backup by storing all versions of files
• GitHub is a web-based platform that provides version control and collaboration tools for software development projects
• GitHub started in 2008 as a version control system and evolved into a social utility for programmers
• Terminology:

  • Repository (Repo): Storage space where project files, code, and version history are stored
  • Commit: A snapshot of changes made to the files in a repository
  • Branch: A separate line of development within a repository
  • Pull Request (PR): A request to merge changes from one branch into another
  • Merge: Combining changes from one branch into another
• Terminology:

  • Fork: Creating a personal copy of someone else's repository
  • Clone: Creating a local copy of a repository on your computer
  • Push: Uploading local changes to the remote repository on GitHub
  • Pull: Retrieving changes from a remote repository and merging them into your local repository
  • Issue: Tracking tasks, enhancements, bugs, or other discussions related to a repository
• Terminology:

  • Label: Categorizes and organizes issues and pull requests
  • Milestone: Groups and tracks a set of related issues or pull requests
  • Collaborator: Someone with access to a repository who can contribute to it
  • README: A file providing important information about the repository
  • Gist: A simple way to share code snippets or small snippets of text
• .gitignore is a file that tells Git which files or folders to ignore in a project
• Entries in .gitignore can follow a matching pattern:

  • * is a wildcard match
  • / is used to ignore pathnames relative to the .gitignore file
  • # is used to add comments to a .gitignore file
• Example of a .gitignore file:

  • Ignore Mac system files .DS_store
  • Ignore node_modules folder node_modules
  • Ignore all text files *.txt
  • Ignore files related to API keys .env
  • Ignore SASS config files .sass-cache
• README file is a text file that introduces and explains a project, containing essential information about the project
• Command Line Interface (CLI) is a program that uses text-based commands to interact with the computer’s operating systems
• CLI allows users to navigate through files and folders in the computer, similar to Windows Explorer on Windows or Finder on Mac OS
• CLI interactions are often faster for experienced users who are comfortable with keyboard input and can quickly execute commands
• CLI applications consume fewer system resources compared to GUI applications
• CLI can be accessed remotely over networks, providing remote access and automation capabilities
• CLI commands allow users to specify exact parameters and options for commands, enabling precise control and flexibility
• CLI allows users to write scripts that can perform series of tasks automatically and sequentially
• CLI can be more intuitive and familiar to those who are comfortable with text-based interfaces and have experience in programming and scripting
• CLI provides direct access to system functions and avoids the resource-intensive nature of GUIs, making it ideal for server management and administration
• CLI often provides detailed information and logs that aid in troubleshooting and diagnosing issues within systems and networks
• CLI applications typically have a smaller attack surface compared to GUI applications, potentially reducing the risk of vulnerabilities
• CLI is more responsive and consumes less data when working with remote servers or devices over slow or limited bandwidth
• Common CLI programs include Bash, Windows Terminal, PowerShell, Terminal (macOS), Windows Subsystem for Linux (WSL), Cygwin, Zsh (Z Shell), Fish (Friendly Interactive Shell), and Tcsh (Tenex C Shell)
• Basic CLI commands for navigating directories:

  • cd: navigate directories
  • dir (or ls on macOS): list contents of the current directory
• To create a new directory, use the mkdir command followed by the directory name
• To create a new empty text file, use the echo command and output the content to a file
• To copy or move files to another location, use the copy or move command followed by the source and destination paths
• To rename or delete files, use the rename or del command followed by the filename
• To delete an empty directory, use the rmdir command followed by the directory name
• To view the content of a text file, use the type command followed by the filename
• To edit a file, use the edit command followed by the filename or use external text editors like Notepad
• To filter and transform text within a file, use commands like find, findstr, grep, sed, and awk
• To combine files, use the copy command with the /b parameter or findstr command with the /n parameter
• Basic Commands in Command Line Interface (CLI):

  • Navigating directories:
  • cd: change directory
  • dir (or ls on macOS): list contents of the current directory
  • To view current directory: $ cd
  • To list contents of the current directory: $ dir
  • To navigate to a different directory: use the ‘cd’ command followed by the directory path
  • To move up one level in the directory structure: $ cd ..
  • To navigate to a specified directory path: $ cd C:\Windows\System32
  • To handle spaces in directory names: enclose the path in double quotes, e.g., $ cd "C:\Program Files"
  • Use TAB key for auto-completion of directory and file names
• Creating, moving, copying, and deleting files and directories:

  • To create a new directory: use mkdir command followed by the directory name, e.g., $ mkdir MyFolder
  • To create a new empty text file: use echo command and output the content to a file, e.g., $ echo . > MyFile.txt
  • To copy a file to another location: use copy command followed by the source and destination paths, e.g., $ copy MyFile.txt C:\Temp\
  • To move a file to another location: use move command, e.g., $ move MyFile.txt C:\Temp\
  • To rename a file: use rename command followed by the current and new filename, e.g., $ rename MyFile.txt NewFile.txt
  • To delete a file: use del command followed by the filename, e.g., $ del NewFile.txt
  • To delete an empty directory: use rmdir command followed by the directory name, e.g., $ rmdir MyFolder
• File content operations:

  • Viewing file content:
  • To view the content of a text file: use type command followed by the filename, e.g., $ type MyFile.txt
  • To view specific lines from the beginning of a file: use type command with the /p parameter, e.g., $ type MyFile.txt | more
  • Editing files:
  • To open a file for editing using Windows basic text editor: use edit command followed by the filename, e.g., $ edit MyFile.txt
  • To open a file for editing using Notepad: use start command followed by the filename, e.g., $ start notepad MyFile.txt
• Working with text:

  • Filtering and transforming text:
  • Commands like find, findstr, grep, sed, and awk can be used
  • Example using findstr: $ findstr "searchword" MyFile.txt
  • Combining files:
  • To combine files: use copy command with the /b parameter, e.g., $ copy /b File1.txt + File2.txt CombinedFile.txt
  • To combine files with line numbers: use findstr command with the /n parameter, e.g., $ findstr /n "^" File1.txt File2.txt > CombinedFileWithNumbers.txt