Bash Terminal commands

In this document, I will be listing some of the most common terminal commands used in bash terminal.

• Ways to go to home directory.

  • cd - Go to home directory.
  • cd ~ - Go to home directory.
  • cd /home/username - Go to home directory.
  • cd $HOME - Go to home directory.
  • cd ../../ - Go two directories back and so on.

• Some general commands

  • ls - List all files in the current directory.
  • ls -l - List all files in the current directory in long format including permissions, owner, group, size, and date.
  • ls -a - List all files in the current directory including hidden files.
  • ls -la - List all files in the current directory in long format including permissions, owner, group, size, and date including hidden files.
  • pwd - Print working directory.
  • file filename - Get the type of file.
  • cd some\ file\ name - Go to a directory with spaces in the name.

• Saving the current directory and going to another directory.

  • pushd directory - Save the current directory and go to the directory which is given.
  • popd - Go back to the directory which is saved by pushd.

• locate filename - Best way to find the any filename in system, you can either provide the exact filename or part of the filename, it will show you all matching paths. It uses a database which is updated by updatedb command as follows sudo updatedb.

• which filename - Check if any such tool is installed in the system or not.

• cal - Show the calendar of the current month.

• cal 2021 - Show the calendar of the year 2021.

• cal 10 2021 - Show calender of 10th month of 2021.

• date - Show the current date and time.

• Command history

  • history - Show the history of commands.
  • !! - Run the last command.
  • !n - Run the nth command from the history.
  • !-n - Run the nth command from the last.
  • Or use up arrow key.

• Knowing about commands

  • whatis command - Get a one-line description of the command.
  • apropos keyword - Search command related to keyword you have provided.
  • man command - Get the manual of the command. It is like documentation of some command. Some commands may not have manual.
  • info command - Get the info of the command. It is like documentation of some command. Some commands may not have info. Works same as man command.

• Working with files and directories

  • mkdir directoryname1 directoryname2 - Create directories, you can provide multiple directories, or you can create directories one by one.
  • touch filename - Create a file, if file already exists then it will update the timestamp of the file, more files can be created at once also like mkdir command.
  • cp filename1 filename2 - Copy the file from filename1 to filename2. If filename2 is a directory then it will copy the file to that directory.
    • Example - cp —/.bashrc bashrc - Copy the file .bashrc to the file bashrc.
  • Note - If you press tab to auto-complete the filename, then if it does it means file exists.. so inclusively it is working like ls command.
  • mv filename1 filename2 - Move the file from filename1 to filename2. If filename2 is a directory then it will move the file to that directory. Also it can be used to rename the file. In this case filename2 is the new name of the filename1.
  • rm filename - It removes the filename file, and their is no way you can get back it to your system.
  • rm * - It removes all files in the current directory.
  • rm file* - It removes all files starting with file in the current directory. For example rm cat* will remove all files starting with cat.
  • rm -r directory - It removes the directory and all files and directories inside it.
  • rm -rf directory - It removes the directory and all files and directories inside it forcefully.
  • rmdir directory - It removes the directory if it is empty.
  • rmdir * - It removes all removes all empty directories in the current directory, it is very useful.

• Working with files content

  • cat filename - Show the content of the file.
  • cat >> filename - Append the content to the file, if file does not exist then it will create the file and write content in it. So basically you're saving effor to create a file through touch, and editing it through nano or vim.
  • cat file1 file2 - Show the content of file1 and file2 combined in terminal.
  • cat file1 file2 > file3 - Combine the content of file1 and file2 and save it in file3.