5.2 Common file syntax
Data files read by these programs are text files that share certain
Comments begin with a `%' character and continue to the end of the
line. The content of comments is entirely ignored.
Blank lines are allowed, and ignored. Whitespace characters (as
defined by the C facility
isspace) are ignored at the beginning of
Any character except ASCII NUL--character zero--is acceptable in data
files. (We would allow NULs, too, at the expense of complicating the
code, if we knew of any useful purpose for them.)
A line can be as long as you want.