NAME
device_printf
,
printf
, printf_nolog
,
snprintf
, vasprintf
,
vprintf
, vsnprintf
,
uprintf
, ttyprintf
,
tprintf_open
, tprintf
,
tprintf_close
,
aprint_normal
, aprint_naive
,
aprint_verbose
,
aprint_debug
, aprint_error
,
aprint_normal_dev
,
aprint_naive_dev
,
aprint_verbose_dev
,
aprint_debug_dev
,
aprint_error_dev
,
aprint_normal_ifnet
,
aprint_naive_ifnet
,
aprint_verbose_ifnet
,
aprint_debug_ifnet
,
aprint_error_ifnet
,
aprint_get_error_count
—
kernel formatted output
conversion
SYNOPSIS
#include
<sys/systm.h>
void
device_printf
(device_t,
const char *format,
...);
void
printf
(const
char *format,
...);
void
printf_nolog
(const
char *format,
...);
int
snprintf
(char
*buf, size_t size,
const char *format,
...);
int
vasprintf
(char
**buf, const char
*format, va_list
ap);
void
vprintf
(const
char *format, va_list
ap);
int
vsnprintf
(char
*buf, size_t size,
const char *format,
va_list ap);
void
uprintf
(const
char *format,
...);
void
ttyprintf
(struct
tty *tty, const char
*format, ...);
#include
<sys/tprintf.h>
tpr_t
tprintf_open
(struct
proc *p);
void
tprintf
(tpr_t
tpr, const char
*format, ...);
void
tprintf_close
(tpr_t
tpr);
void
aprint_normal
(const
char *format,
...);
void
aprint_naive
(const
char *format,
...);
void
aprint_verbose
(const
char *format,
...);
void
aprint_debug
(const
char *format,
...);
void
aprint_error
(const
char *format,
...);
void
aprint_normal_dev
(device_t,
const char *format,
...);
void
aprint_naive_dev
(device_t,
const char *format,
...);
void
aprint_verbose_dev
(device_t,
const char *format,
...);
void
aprint_debug_dev
(device_t,
const char *format,
...);
void
aprint_error_dev
(device_t,
const char *format,
...);
void
aprint_normal_ifnet
(struct
ifnet *, const char
*format, ...);
void
aprint_naive_ifnet
(struct
ifnet *, const char
*format, ...);
void
aprint_verbose_ifnet
(struct
ifnet *, const char
*format, ...);
void
aprint_debug_ifnet
(struct
ifnet *, const char
*format, ...);
void
aprint_error_ifnet
(struct
ifnet *, const char
*format, ...);
int
aprint_get_error_count
(void);
DESCRIPTION
Theprintf
()
family of functions allows the kernel to send formatted messages to various
output devices. The functions printf
() and
vprintf
()
send formatted strings to the system console. The
device_printf
()
function is identical to printf
(), except that it
prefixes the log message with the corresponding device name. The
printf_nolog
()
function is identical to printf
(), except it does not
send the data to the system log. The functions
snprintf
(),
vasprintf
(),
and
vsnprintf
()
write output to a string buffer. These five functions work similarly to their
user space counterparts, and are not described in detail here. The
vasprintf
() function allocates memory with
kmem_alloc(9) and it is the caller's responsibility to free the
returned string with
kmem_free(9).
The functions
uprintf
()
and
ttyprintf
()
send formatted strings to the current process's controlling tty and a
specific tty, respectively.
The
tprintf
()
function sends formatted strings to a process's controlling tty, via a
handle of type tpr_t. This allows multiple write operations to the tty with
a guarantee that the tty will be valid across calls. A handle is acquired by
calling
tprintf_open
()
with the target process as an argument. This handle must be closed with a
matching call to
tprintf_close
().
The functions
aprint_normal
(),
aprint_naive
(),
aprint_verbose
(),
aprint_debug
(),
and
aprint_error
()
are intended to be used to print
autoconf(9) messages. Their verbosity depends on flags set in the
boothowto variable, through options passed during
bootstrap; see
boothowto(9) and Interactive
mode in boot(8):
AB_SILENT
- silent mode, enabled by
boot
-z
. AB_QUIET
- quiet mode, enabled by
boot
-q
. AB_VERBOSE
- verbose mode, enabled by
boot
-v
. AB_DEBUG
- debug mode, enabled by
boot
-x
.
The
aprint_*
()
functions have the following behaviour, based on the above mentioned
flags:
aprint_normal
()- Sends to the console unless
AB_QUIET
is set. Always sends to the log. aprint_naive
()- Sends to the console only if
AB_QUIET
is set. Never sends to the log. aprint_verbose
()- Sends to the console only if
AB_VERBOSE
is set. Always sends to the log. aprint_debug
()- Sends to the console and the log only if
AB_DEBUG
is set. aprint_error
()- Like
aprint_normal
(), but also keeps track of the number of times called. This allows a subsystem to report the number of errors that occurred during a quiet or silent initialization phase.
For the
aprint_*
()
functions there are two additional families of functions with the suffixes
_dev
and _ifnet
which work
like their counterparts without the suffixes, except that they take a
device_t and struct ifnet *,
respectively, as first argument, and prefix the log message with the
corresponding device or interface name.
The
aprint_get_error_count
()
function reports the number of errors and resets the counter to 0.
If AB_SILENT
is set, none of the
autoconfiguration message printing routines send output to the console. The
AB_VERBOSE
and AB_DEBUG
flags override AB_SILENT
.
RETURN VALUES
The snprintf
() and
vsnprintf
() functions return the number of
characters that would have been placed in the buffer
buf. if there was enough space in the buffer, not
including the trailing NUL
character used to
terminate output strings like the user-space functions of the same name.
The tprintf_open
() function returns
NULL
if no terminal handle could be acquired.
CODE REFERENCES
sys/kern/subr_prf.c
SEE ALSO
printf(1), printf(3), snprintb(3), boot(8), autoconf(9), boothowto(9)
HISTORY
In NetBSD 1.5 and earlier,
printf
() supported more format strings than the user
space printf
(). These nonstandard format strings are
no longer supported. For the functionality provided by the former
%b
format string, see
snprintb(3).
The aprint_normal
(),
aprint_naive
(),
aprint_verbose
(), and
aprint_debug
() functions first appeared in
BSD/OS.
BUGS
The uprintf
() and
ttyprintf
() functions should be used sparingly, if
at all. Where multiple lines of output are required to reach a process's
controlling terminal, tprintf
() is preferred.