ordinary multibyte characters are copied unchanged to the output

conversion specifications are begun with % and consist of

• zero or more flags

   
  	-     left-justify 
  	+     number is printed with a sign
  	space prefixes space to beginning if there is no sign
  	#     "alternate form" -- with o, increases precision so first
  	      digit is zero; for x, prefixes "0x"; for e, E, f, g, G,
  	      always puts decimal, even if no fractional part; for g and G,
  	      trailing zeros are not removed
  	0     leading zeros are used to pad, rather than spaces
        

• optional field width -- argument will be printed in a field at least this wide, padded if necessary
• period separating field width and precision
• optional precision -- maximum number of characters to be printed in a string, or number of digits after the decimal point or number of significant digits, or minimum digits in an integer
• optional length modifier

  	  h    short
  	 l,L   long
  	 

• conversion specifier

  	 d, i     int, signed decimal
  	   o      int, unsigned octal
  	 x, X     int, unsigned hexadecimal
  	   u      int, unsigned decimal
  	   c      int, single character after conversion to unsigned char
  	   s      char *, characters from string are printed until '\0'
  		  is reached or precision characters have been printed
  	   f      double, decimal notation, default precision 6
  	 e, E     double, scientific notation, default precision 6
           g, G     double, uses scientific notation if exponent is less
  		  than -4 or greater than or equal to the precision,
  		  uses decimal notation otherwise
  	   p      void *, pointer (representation implementation-dependent)
  	   %      no conversion, just print a '%'
  	   n      this argument gives a pointer to an integer, and printf
  		  writes to this integer the number of characters written
  		  to the output stream so far. no conversion