Node:Format directives, Next:Formats for numbers, Previous:Format interpretation, Up:Formatted output
A format directive begins with a %.
Then there may be an optional a #, which usually
means that the argument should be printed in a "readable"
format (that is: if the output is read back, the result
should be equal to the orginal argument).
Finally, the format directive is terminated by a single format specification characer, which species what kind of formatting to do.
The format directive %% uses no arguments, and
outputs a single %.