To append the information to an existing file, which type of redirector should be used?
<<
>
>>
To append information to an existing file in most command-line interfaces (like bash in Unix/Linux or the Windows Command Prompt), you should use the double greater-than sign redirector `>>`.
Here's how to use it:
```bash
echo "This is a new line" >> yourfile.txt
```
With this command, "This is a new line" will be added to the end of `yourfile.txt` without deleting its current contents. If `yourfile.txt` doesn't exist, it will be created with the text you echo.
For reference, here is what the other redirectors do:
- `>` is used for redirection. It will create a new file or overwrite the existing file with the output of the command.
- `<<` is used as a here-document redirector, which feeds a sequence of lines into a command until a designated end-of-file marker is reached.
Remember that redirection can behave differently depending on the command-line interpreter you're using. The explanation given here is based on common Unix-like shells (such as bash, sh, ksh, zsh, etc.) and the cmd.exe and PowerShell interpreters on Windows.