Add documentation for log(9).

MFC after:	1 week

2 files changed, 46 insertions, 5 deletions

diff --git a/share/man/man9/Makefile b/share/man/man9/Makefile
index fb4bb65..ee6a34e 100644
--- a/share/man/man9/Makefile
+++ b/share/man/man9/Makefile
@@ -676,7 +676,8 @@ MLINKS+=pmap_resident_count.9 pmap_wired_count.9
 MLINKS+=pmap_zero_page.9 pmap_zero_area.9 \
 	pmap_zero_page.9 pmap_zero_idle.9
 MLINKS+=printf.9 tprintf.9 \
-	printf.9 uprintf.9
+	printf.9 uprintf.9 \
+	printf.9 log.9
 MLINKS+=psignal.9 gsignal.9 \
 	psignal.9 pgsignal.9
 MLINKS+=random.9 arc4rand.9 \
diff --git a/share/man/man9/printf.9 b/share/man/man9/printf.9
index b3b3189..8a8d340 100644
--- a/share/man/man9/printf.9
+++ b/share/man/man9/printf.9
@@ -1,5 +1,6 @@
 .\"
 .\" Copyright (c) 2001 Andrew R. Reiter
+.\" Copyritht (c) 2004 Joerg Wunsch
 .\" All rights reserved.
 .\"
 .\" Redistribution and use in source and binary forms, with or without
@@ -25,11 +26,11 @@
 .\"
 .\" $FreeBSD$
 .\"
-.Dd April 25, 2001
+.Dd August 10, 2004
 .Dt PRINTF 9
 .Os
 .Sh NAME
-.Nm printf , uprintf , tprintf
+.Nm printf , uprintf , tprintf, log
 .Nd formatted output conversion
 .Sh SYNOPSIS
 .In sys/types.h
@@ -40,13 +41,15 @@
 .Fn tprintf "struct proc *p" "int pri" "const char *fmt" "..."
 .Ft int
 .Fn uprintf "const char *fmt" "..."
+.Ft void
+.Fn log "int pri" "const char *fmt" "..."
 .Sh DESCRIPTION
 The
 .Xr printf 9
 family of functions are similar to the
 .Xr printf 3
 family of functions.
-The three functions each use a different output stream.
+The different functions each use a different output stream.
 The
 .Fn uprintf
 function outputs to the current process' controlling tty, while
@@ -59,6 +62,11 @@ function outputs to the tty associated with the process
 and the logging facility if
 .Fa pri
 is not \&-1.
+The
+.Fn log
+function sends the message to the kernel logging facility, using
+the log level as indicated by
+.Fa pri .
 .Pp
 Each of these related functions use the
 .Fa fmt
@@ -102,6 +110,28 @@ a time.
 The string is used as a delimiter between individual bytes.
 If present, a width directive will specify the number of bytes to display.
 By default, 16 bytes of data are output.
+.Pp
+The
+.Fn log
+function uses
+.Xr syslog 3
+level values
+.Dv LOG_DEBUG
+through
+.Dv LOG_EMERG
+for its
+.Fa pri
+parameter (mistakenly called
+.Sq priority
+here).
+Alternatively, if a
+.Fa pri
+of \&-1 is given, the message will be appended to the last log message
+started by a previous call to
+.Fn log .
+As these messages are generated by the kernel itself, the facility will
+always be
+.Dv LOG_KERN .
 .Sh RETURN VALUES
 The
 .Fn printf
@@ -126,5 +156,15 @@ will produce the following output:
 reg=3<BITTWO,BITONE>
 out: 41:41:41:41
 .Ed
+.Pp
+The call
+.Bd -literal -offset indent
+log(LOG_DEBUG, "%s%d: been there.\\n", sc->sc_name, sc->sc_unit);
+.Ed
+.Pp
+will add the appropriate debug message at priority
+.Em kern.debug
+to the system log.
 .Sh SEE ALSO
-.Xr printf 3
+.Xr printf 3 ,
+.Xr syslog 3