Variable column widths, string lengths in printf-style functions

Tagged:

I have been programming in C for quite some time, but until recently I was not aware that you could specify column widths and string limits using variables. I have neither seen this functionality used in any projects until I started working with OpenSER.

Specify a variable column width:

printf("%*d", width, number);

Specify a variable number of characters from a string:

printf("%.*s", width, string);

Can you please post a link to document explaining this feature