Today encountered asterisk (*) when refering the printf() function. I met with it long long ago, but what it is has gone away from my mind absolutely…What the man said about the asterisk (*) is as the follows:

The format of printf() is like this

%[flags][fldwidth][precision][lenmodifier]convtype

   Format of the format string
       The  format string is a character string, beginning and ending in its initial shift state, if any.  The format string is composed
       of zero or more directives: ordinary characters (not %), which are copied unchanged to the output stream; and conversion specifi-
       cations, each of which results in fetching zero or more subsequent arguments.  Each conversion specification is introduced by the
       character %, and ends with a conversion specifier.  In between there may be (in this order) zero or more flags, an optional mini-
       mum field width, an optional precision and an optional length modifier.

       The  arguments must correspond properly (after type promotion) with the conversion specifier.  By default, the arguments are used
       in the order given, where each `* ‘ and each conversion specifier asks for the next argument (and it is an error if insufficiently
       many arguments are given).  One can also specify explicitly which argument is taken, at each place where an argument is required,
       by writing `%m$’ instead of `%’ and `*m$’ instead of `*‘ , where the decimal integer m denotes the position in the  argument  list
       of the desired argument, indexed starting from 1.  Thus,

           printf("%*d", width, num);  # width is passed to ‘*’ as the [fldwidth] of the argument num

       and

           printf("%2$*1$d", width, num);

       are  equivalent.   The second style allows repeated references to the same argument.  The C99 standard does not include the style
       using `$’, which comes from the Single Unix Specification.  If the style using `$’ is used, it must be used  throughout  for  all
       conversions  taking an argument and all width and precision arguments, but it may be mixed with `%%’ formats which do not consume
       an argument.  There may be no gaps in the numbers of arguments specified using `$’; for example, if arguments 1 and 3 are  speci-
       fied, argument 2 must also be specified somewhere in the format string.

Then I will write down the flags associated with printf() as my memo