B.3 Configuration files

Most configuration files have a common form:

• Each line forms a separate command or directive. This means that lines cannot be broken up, unless they are spliced together with a trailing backslash, as described below.
• Before anything else is done, trailing white space is removed.
• When a line ends in a backslash (\), the backslash is removed, and the next line is read and appended to the current line.
  • White space preceding the backslash is retained.
  • This rule continues to be applied until the line read does not end in a backslash.
  • It is an error if the last line in the file ends in a backslash.
• Comments are introduced by an octothorpe (#), and continue until the end of the line.
  • An octothorpe inside balanced pairs of double quotation marks (") or single quotation marks (') does not introduce a comment.
  • The backslash character can be used inside balanced quotes of either type to escape the following character as a literal character.

    (This is distinct from the use of a backslash as a line-splicing character.)

  • Line splicing takes place before comment removal.
• Blank lines, and lines that contain only white space, are ignored.