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
The sprintf() function builds a string in buf under the control of the
format fmt. The format is a character string with either plain charac‐
ters, 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 conver‐
sion. 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 charac‐
ters, 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>\n in buf.
sprintf(buf, "reg=%b\n", 3, "\10\2BitTwo\1BitOne")
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 encountered. If the charac‐
ter pointer is NULL, the string <null string> is used
in its place.
% Copy a %; no argument is converted.
RETURN VALUES
The sprintf() function returns its first argument, buf.
The snprintf() function 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
characters formatted.
CONTEXT
The sprintf() and snprintf() functions and can be called from user,
interrupt, or kernel context.
SEE ALSOSunOS 5.10 16 Jan 2006 sprintf(9F)
