sprintf(9F)						   Kernel Functions for Drivers 					       sprintf(9F)

NAME

       sprintf, snprintf - format characters in memory

SYNOPSIS

       #include <sys/ddi.h>

       char *sprintf(char *buf, const char *fmt, ...);

       size_t snprintf(char *buf, size_t n, const char *fmt, ...);

INTERFACE LEVEL

       Solaris DDI specific (Solaris DDI).

PARAMETERS

       buf	       Pointer to a character string.

       fmt	       Pointer to a character string.

DESCRIPTION

       sprintf()  builds a string in buf under the control of the format fmt. The format is a character string with either plain characters, which
       are simply copied into buf, or conversion specifications, each of which converts zero or more arguments, again copied into buf. The results
       are  unpredictable if there are insufficient arguments for the format; excess arguments are simply ignored. It is the user's responsibility
       to ensure that enough storage is available for buf.

       The snprintf() function is identical to sprintf() with the addition of the argument n, which specifies the size of the buffer  referred	to
       by buf. The buffer is always terminated with the null byte.

   Conversion Specifications
       Each conversion specification is introduced by the % character, after which the following appear in sequence:

       An optional value specifying a minimum field width for numeric conversion. The converted value will be right-justified and, if it has fewer
       characters than the minimum, is padded with leading spaces unless the field width is an octal value, then it is padded with leading zeroes.

       An optional l (ll) specifying that a following d, D, o, O, x, X, or u conversion character applies to a long (long long) integer  argument.
       An l (ll) before any other conversion character is ignored.

       A character indicating the type of conversion to be applied:

       d,D,o,O,x,X,u

	   The integer argument is converted to signed decimal (d, D), unsigned octal (o, O), unsigned hexadecimal (x, X) or unsigned decimal (u),
	   respectively, and copied. The letters abcdef are used for x conversion. The letters ABCDEF are used for X conversion.

       c

	   The character value of argument is copied.

       b

	   This conversion uses two additional arguments. The first is an integer, and is converted according to the base specified in the  second
	   argument.  The  second argument is a character string in the form <base>[<arg>...]. The base supplies the conversion base for the first
	   argument as a binary value; 10 gives octal, 20 gives hexadecimal. Each subsequent <arg> is a sequence of  characters,  the  first	of
	   which  is the bit number to be tested, and subsequent characters, up to the next bit number or terminating null, supply the name of the
	   bit.

	   A bit number is a binary-valued character in the range 1-32. For each bit set in the first argument, and named in the second  argument,
	   the	bit  names  are  copied,  separated  by  commas,  and  bracketed  by  <  and  >.  Thus, the following function call would generate
	   reg=3<BitTwo,BitOne>
 in buf.

	   sprintf(buf, "reg=%b
", 3, "102BitTwo1BitOne")

       p

	   The argument is taken to be a pointer; the value of the pointer is displayed in unsigned hexadecimal. The display format is	equivalent
	   to %lx. To avoid lint warnings, cast pointers to type void * when using the %p format specifier.

       s

	   The	argument  is taken to be a string (character pointer), and characters from the string are copied until a null character is encoun-
	   tered. If the character pointer is NULL, the string <null string> is used in its place.

       %

	   Copy a %; no argument is converted.

RETURN VALUES

       sprintf() returns its first argument, buf.

       snprintf() returns the number of characters formatted, that is, the number of characters that would have been written to the buffer  if	it
       were  large enough. If the value of n is less than or equal to 0 on a call to snprintf(), the function simply returns the number of charac-
       ters formatted.

CONTEXT

       sprintf() and snprintf() can be called from user or interrupt context.

SEE ALSO

       Writing Device Drivers

SunOS 5.10							    11 Feb 2003 						       sprintf(9F)