Bash 명령어

📂 Directory Commands

• pwd : Display the absolute path of the current directory.

• cd (directory_name) : Change to the specified directory.

• cd .. : Move up one directory (to the parent directory).

• ls : List all files and directories in the current directory.

• ls -la : Display detailed information for all files and directories, including hidden files (those that start with .).

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🛠️ Directory & File Operations (Create, Move, Delete)

• mkdir (directory_name) : Create a new directory.

• rm (file_name) : Delete a file or directory.

• rm -rf (directory_name) : Recursively force-delete a directory and its contents.

• cp (source) (destination) : Copy files or directories from the source to the destination.

• mv (source) (destination) or mv (old_name) (new_name) : Move a file (cut and paste) or rename a file.

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📄 File Output

• touch (file_name) : Create a new file.

• cat (file_name) : Display the contents of a file.

• echo 'txt_to_write' > (file_name) : Write text to a file (overwrite if it exists).

  • > : Overwrite the file.
  • >> : Append to the file.

• echo : Can be used to view environment variable values, similar to Console.log.

• export (ENVIRONMENT_VARIABLE)=(value) : Set an environment variable and use echo to confirm it.

  • This applies only to the session, so to save it, you can use vi ~/.bashrc to add the export command.
  • Save with :wq, then update with source ~/.bashrc to apply.

• head -n 3 (file_name) : Display the first 3 lines of a file.

• tail -n 3 (file_name) : Display the last 3 lines of a file.

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🔄 Command Chaining

• ls | sort | less : Pipe the output of the ls command into sort, and then pipe that result into less for viewing.

• grep : Search for a specific pattern or regular expression in a string.

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🔧 Other Command Modifiers

• && : Perform independent commands (the output of one does not affect the next).

• ; : Execute the next command even if the previous one fails.

• & : Run the next command concurrently with the previous one.

• || : Execute the next command only if the previous one fails.

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🛠️ Utilities

• chmod : Change file permissions.

  • Read (4), Write (2), Execute (1)

  • Example: 7 = Read + Write + Execute

  • Example: 1 = Execute only

  • First digit: Owner permissions.

  • Second digit: Group permissions.

  • Third digit: Other permissions.

  • Example: 700 : Only the owner can read, write, and execute.

• tar : Extract files from a TAR archive.

• sudo : Execute a command with superuser privileges (root access).

• vi : Text editor.

• code : VSCode editor.