document vsnprintf_ss

lib/libc/stdio/Makefile.inc

@@ -1,5 +1,5 @@
 #	from: @(#)Makefile.inc	5.7 (Berkeley) 6/27/91
-#	$NetBSD: Makefile.inc,v 1.39 2010/09/24 21:50:56 christos Exp $
+#	$NetBSD: Makefile.inc,v 1.40 2010/12/22 16:59:10 christos Exp $
 
 # stdio sources
 .PATH: ${.CURDIR}/stdio
@@ -52,7 +52,7 @@ MLINKS+=mktemp.3 mkdtemp.3 mktemp.3 mkstemp.3
 MLINKS+=printf.3 asprintf.3 printf.3 fprintf.3 printf.3 snprintf.3 \
 	printf.3 sprintf.3 printf.3 vasprintf.3 printf.3 vfprintf.3 \
 	printf.3 vprintf.3 printf.3 vsnprintf.3 printf.3 vsprintf.3 \
-	printf.3 dprintf.3 printf.3 vdprintf.3
+	printf.3 dprintf.3 printf.3 vdprintf.3 printf.3 vsnprintf_ss.3
 MLINKS+=putc.3 fputc.3 putc.3 putc_unlocked.3 putc.3 putchar.3 \
 	putc.3 putchar_unlocked.3 putc.3 putw.3
 MLINKS+=scanf.3 fscanf.3 scanf.3 sscanf.3 scanf.3 vfscanf.3 scanf.3 vscanf.3 \

lib/libc/stdio/printf.3

@@ -1,4 +1,4 @@
-.\"	$NetBSD: printf.3,v 1.55 2010/12/16 17:42:27 wiz Exp $
+.\"	$NetBSD: printf.3,v 1.56 2010/12/22 16:59:10 christos Exp $
 .\"
 .\" Copyright (c) 1990, 1991, 1993
 .\"	The Regents of the University of California.  All rights reserved.
@@ -33,7 +33,7 @@
 .\"
 .\"     @(#)printf.3	8.1 (Berkeley) 6/4/93
 .\"
-.Dd August 28, 2010
+.Dd December 22, 2010
 .Dt PRINTF 3
 .Os
 .Sh NAME
@@ -48,6 +48,7 @@
 .Nm vsprintf ,
 .Nm vdprintf ,
 .Nm vsnprintf ,
+.Nm vsnprintf_ss ,
 .Nm vasprintf
 .Nd formatted output conversion
 .Sh LIBRARY
@@ -78,6 +79,8 @@
 .Ft int
 .Fn vsnprintf "char * restrict str" "size_t size" "const char * restrict format" "va_list ap"
 .Ft int
+.Fn vsnprintf_ss "char * restrict str" "size_t size" "const char * restrict format" "va_list ap"
+.Ft int
 .Fn vasprintf "char ** restrict ret" "const char * restrict format" "va_list ap"
 .Sh DESCRIPTION
 The
@@ -106,8 +109,9 @@ write output to the give file descriptor
 .Fn sprintf ,
 .Fn snprintf ,
 .Fn vsprintf ,
+.Fn vsnprintf ,
 and
-.Fn vsnprintf
+.Fn vsnprintf_ss
 write to the character string
 .Fa str ;
 and
@@ -124,6 +128,9 @@ string that specifies how subsequent arguments
 .Xr stdarg 3 )
 are converted for output.
 .Pp
+.Fn vsnprintf_ss
+is a signal-safe standalone version that does handle floating point formats.
+.Pp
 .Fn asprintf
 and
 .Fn vasprintf
@@ -148,9 +155,10 @@ argument to
 on error.
 It is more portable to check for a return value of \-1 instead.
 .Pp
-.Fn snprintf
-and
+.Fn snprintf ,
 .Fn vsnprintf
+and
+.Fn vsnprintf_ss
 will write at most
 .Fa size Ns \-1
 of the characters printed into the output string
@@ -725,9 +733,10 @@ field is expanded to contain the conversion result.
 These functions return
 the number of characters printed, or that would be printed if there
 was adequate space in case of
-.Fn snprintf
-and
+.Fn snprintf ,
 .Fn vsnprintf ,
+and
+.Fn vsnprintf_ss
 (not including the trailing
 .Ql \e0
 used to end output to strings).
@@ -825,6 +834,10 @@ The functions
 and
 .Fn vasprintf
 are modeled on the ones that first appeared in the GNU C library.
+The function
+.Fn vsnprintf_ss
+is non standard and appeared in
+.Nx 4.0 .
 The functions
 .Fn dprintf
 and