NAME
kprintf, ksprintf,
ksnprintf, kvprintf,
kvsprintf, kvsnprintf,
krateprintf, tprintf,
uprintf, log —
formatted output conversion
SYNOPSIS
#include
<sys/types.h>
#include <sys/systm.h>
int
kprintf(const
char *format,
...);
int
ksprintf(char
*str, const char
*format, ...);
int
ksnprintf(char
*str, size_t size,
const char *format,
...);
int
kvprintf(const
char *format, __va_list
ap);
int
kvsprintf(char
*str, const char
*format, __va_list
ap);
int
kvsnprintf(char
*str, size_t size,
const char *format,
__va_list ap);
void
krateprintf(struct
krate *rate, const char
*format, ...);
int
uprintf(const
char *format,
...);
#include
<sys/tprintf.h>
int
tprintf(struct
proc *p, int pri,
const char *format,
...);
#include
<sys/syslog.h>
int
log(int
pri, const char
*format, ...);
DESCRIPTION
Thekprintf family of functions are similar to the
printf(3) family of functions. The different functions each use a
different output stream. The
uprintf()
function outputs to the current process' controlling tty, while
kprintf(),
ksprintf(),
ksnprintf(),
kvprintf(),
kvsprintf()
and
kvsnprintf()
write to the console as well as to the logging facility. The
tprintf()
function outputs to the tty associated with the process
p and the logging facility if pri
is not -1. The log() function sends the message to the
kernel logging facility, using the log level as indicated by
pri.
Each of these related functions use the
format, str,
size and va parameters in the
same manner as
printf(3). However, the kprintf functions add
another conversion specifier to format:
The %pb%i identifier expects two
arguments: an char * and a int.
These are used as a register value and a print mask for decoding bitmasks.
The print mask is made up of two parts: the base and the arguments. The base
value is the output base expressed as an integer value; for example, \10
gives octal and \20 gives hexadecimal. The arguments are made up of a
sequence of bit identifiers. Each bit identifier begins with an integer
value which is the number of the bit (starting from 1) this identifier
describes. The rest of the identifier is a string of characters containing
the name of the bit. The string is terminated by either the bit number at
the start of the next bit identifier or NUL for the
last bit identifier.
The
log() function
uses syslog(3) level values LOG_DEBUG
through LOG_EMERG for its pri
parameter (mistakenly called ‘priority’ here). Alternatively,
if a pri of -1 is given, the message will be appended
to the last log message started by a previous call to
log(). As these messages are generated by the kernel
itself, the facility will always be LOG_KERN.
The
krateprintf()
function is a rate controlled version of
kprintf().
The freq member of the struct
krate pointed to by rate must be initialized
with the desired reporting frequency. A freq of 0 will
result in no output. Initializing count to a negative
value allows an initial burst.
RETURN VALUES
The kprintf(),
ksprintf(), ksnprintf(),
kvprintf(), kvsprintf(),
kvsnprintf(), tprintf(),
uprintf(), and log()
functions return the number of characters displayed.
EXAMPLES
This example demonstrates the use of the
%pb%i conversion specifier. The function
void
kprintf_test(void)
{
kprintf("reg=%pb%i\n", "\10\2BITTWO\1BITONE\n", 3);
}
will produce the following output:
reg=3<BITTWO,BITONE>
The call
log(LOG_DEBUG, "%s%d: been there.\n", sc->sc_name, sc->sc_unit);
will add the appropriate debug message at priority
“kern.debug” to the system log.