Command line tools

Stop a command

• Press Ctrl + C: interrupt the currently running command and return to the prompt.

This is super useful if you accidentally start a command that takes too long or behaves unexpectedly. It also works if a command is waiting for input and you want to cancel it. Finally, it can be a quick way to start over if you made a mistake typing a command.

Autocomplete

• Press Tab: complete when there's only one match.
• Press Tab twice: show choices when there are multiple matches.

This works for commands, files, folders, and many options. For example:

• gi → git
• cd Doc → cd Documents/
• git ch → git checkout/git cherry-pick

Command history

• Press Up / Down: navigate through commands you've run before.
• Press Ctrl + R: reverse search through your command history (type to filter, Enter to run).
• history: print your history list.
• !!: rerun the last command.

Arguments, quotation marks and special characters

When passing arguments to commands, be mindful of spaces and special characters. When dealing with paths or filenames that contain spaces, enclose the paths in quotation marks (" or ') to ensure they are treated as a single argument. Alternatively, you can escape the space with a backslash (\). For example:

• Wrong: rm My Project (will be interpreted as removing two different paths: My and Project)
• Correct:
  • rm "My Project"
  • git add 'My Project'
  • git add My\ Project

If you don't close the quotation marks properly, the terminal will think you're still typing the argument and wait for you to finish it (displaying dquote> on a new line). Either close the quotation mark on the new line or cancel this by pressing Ctrl + C.

Multiline arguments

Pressing Enter in the terminal usually executes the command you've typed right away.

However, sometimes you want to split a long command or argument across multiple lines for better readability. In this case, you can type a backslash (\) at the end of the line to indicate that the command continues on the next line. For example:

git rebase -i HEAD~5 \
--autosquash \
--keep-empty

However, there's a little gotcha here: using backslashes like this only affects how the command is displayed in the terminal; it does not insert actual line breaks into the argument itself. For example:

echo "First line\
Second line"

Results in:

First lineSecond line

To put the actual line breaks into the string, you must include the newline character (represented by \n) within the quotes, like this:

echo "First line\nSecond line"

Or, if you want to format it across multiple lines:

echo "First line\n\
Second line"

This will produce:

First line
Second line