What are common heredoc delimiters?

Common heredoc delimiters in Linux shell scripting can be any string, but there are a few conventions that are frequently used. The most common delimiters include:

1. EOF: This is the most widely used delimiter. It stands for "End Of File."

   command <<EOF
   content
   EOF

2. END: Another popular choice, similar to EOF.

   command <<END
   content
   END

3. HEREDOC: This is also used, especially when the purpose of the heredoc is to be more descriptive.

   command <<HEREDOC
   content
   HEREDOC

4. CUSTOM_STRING: You can use any string as a delimiter, as long as it is consistent at both the start and end of the heredoc.

   command <<CUSTOM_STRING
   content
   CUSTOM_STRING

The choice of delimiter is flexible, but it's important to ensure that the chosen delimiter does not appear in the content of the heredoc itself. This prevents confusion and ensures proper termination of the heredoc.