In a here document, what does the delimiter mark?

• A. End of a normal script
• B. Start of a here document
• C. End of the here document input
• D. Delimiter that escapes variables

Answer: (C)

The delimiter marks the end of the block of text that will be fed to the command. After the here-document is started with <<, the shell reads lines of input until it encounters a line that contains only the delimiter, and that line ends the here-document input. The content between the starting line and the ending delimiter is what gets passed to the command. If you quote the delimiter, you can control whether variables and other expansions are performed inside the block; without quotes, the shell may expand variables as it reads the text.