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If applicable, add the following below this CDDL HEADER, with the fields enclosed by brackets "[]" replaced with your own identifying information: Portions Copyright [yyyy] [name of copyright owner] .TH vprintf 3C "7 Jan 2009" "SunOS 5.11" "Standard C Library Functions" .SH NAME vprintf, vfprintf, vsprintf, vsnprintf, vasprintf \- print formatted output of a variable argument list .SH SYNOPSIS .LP .nf #include #include \fBint\fR \fBvprintf\fR(\fBconst char *\fR\fIformat\fR, \fBva_list\fR \fIap\fR); .fi .LP .nf \fBint\fR \fBvfprintf\fR(\fBFILE *\fR\fIstream\fR, \fBconst char *\fR\fIformat\fR, \fBva_list\fR \fIap\fR); .fi .LP .nf \fBint\fR \fBvsprintf\fR(\fBchar *\fR\fIs\fR, \fBconst char *\fR\fIformat\fR, \fBva_list\fR \fIap\fR); .fi .LP .nf \fBint\fR \fBvsnprintf\fR(\fBchar *\fR\fIs\fR, \fBsize_t\fR \fIn\fR, \fBconst char *\fR\fIformat\fR, \fBva_list\fR \fIap\fR); .fi .LP .nf \fBint\fR \fBvasprintf\fR(\fBchar **\fR\fIret\fR, \fBconst char *\fR\fIformat\fR, \fBva_list\fR \fIap\fR); .fi .SH DESCRIPTION .sp .LP The \fBvprintf()\fR, \fBvfprintf()\fR, \fBvsprintf()\fR, \fBvsnprintf()\fR, and \fBvasprintf()\fR functions are the same as \fBprintf()\fR, \fBfprintf()\fR, \fBsprintf()\fR, \fBsnprintf()\fR, and \fBasprintf()\fR, respectively, except that instead of being called with a variable number of arguments, they are called with an argument list as defined in the \fB\fR header. See \fBprintf\fR(3C). .sp .LP The \fB\fR header defines the type \fBva_list\fR and a set of macros for advancing through a list of arguments whose number and types may vary. The argument \fIap\fR to the \fBvprint\fR family of functions is of type \fBva_list\fR. This argument is used with the <\fBstdarg.h\fR> header file macros \fBva_start()\fR, \fBva_arg()\fR, and \fBva_end()\fR (see \fBstdarg\fR(3EXT)). The \fBEXAMPLES\fR section below demonstrates the use of \fBva_start()\fR and \fBva_end()\fR with \fBvprintf()\fR. .sp .LP The macro \fBva_alist()\fR is used as the parameter list in a function definition, as in the function called \fBerror()\fR in the example below. The macro \fBva_start(\fR\fIap, name\fR\fB),\fR where \fIap\fR is of type \fBva_list\fR and \fIname\fR is the rightmost parameter (just before \|.\|.\|.), must be called before any attempt to traverse and access unnamed arguments is made. The \fBva_end(\fR\fIap\fR\fB)\fR macro must be invoked when all desired arguments have been accessed. The argument list in \fIap\fR can be traversed again if \fBva_start()\fR is called again after \fBva_end()\fR. In the example below, the \fBerror()\fR arguments (\fIarg1\fR, \fIarg2\fR, \&.\|.\|.) are passed to \fBvfprintf()\fR in the argument \fIap\fR. .SH RETURN VALUES .sp .LP Refer to \fBprintf\fR(3C). .SH ERRORS .sp .LP The \fBvprintf()\fR and \fBvfprintf()\fR functions will fail if either the \fIstream\fR is unbuffered or the \fIstream\fR's buffer needed to be flushed and: .sp .ne 2 .mk .na \fB\fBEFBIG\fR\fR .ad .RS 9n .rt The file is a regular file and an attempt was made to write at or beyond the offset maximum. .RE .SH EXAMPLES .LP \fBExample 1 \fRUsing \fBvprintf()\fR to write an error routine. .sp .LP The following demonstrates how \fBvfprintf()\fR could be used to write an error routine: .sp .in +2 .nf #include #include \&. . . /* * error should be called like * error(function_name, format, arg1, \&.\|.\|.); */ void error(char *function_name, char *format, \&.\|.\|.) { va_list ap; va_start(ap, format); /* print out name of function causing error */ (void) fprintf(stderr, "ERR in %s: ", function_name); /* print out remainder of message */ (void) vfprintf(stderr, format, ap); va_end(ap); (void) abort(); } .fi .in -2 .SH ATTRIBUTES .sp .LP See \fBattributes\fR(5) for descriptions of the following attributes: .sp .sp .TS tab() box; cw(2.75i) |cw(2.75i) lw(2.75i) |lw(2.75i) . ATTRIBUTE TYPEATTRIBUTE VALUE _ Interface StabilityCommitted _ MT-LevelSee below. _ StandardSee below. .TE .sp .LP All of these functions can be used safely in multithreaded applications, as long as \fBsetlocale\fR(3C) is not being called to change the locale. .sp .LP See \fBstandards\fR(5) for the standards conformance of \fBvprintf()\fR, \fBvfprintf()\fR, \fBvsprintf()\fR, and \fBvsnprintf()\fR. The \fBvasprintf()\fR function is modeled on the one that appears in the FreeBSD, NetBSD, and GNU C libraries. .SH SEE ALSO .sp .LP \fBprintf\fR(3C), \fBattributes\fR(5), \fBstdarg\fR(3EXT), \fBattributes\fR(5), \fBstandards\fR(5) .SH NOTES .sp .LP The \fBvsnprintf()\fR return value when \fIn\fR = 0 was changed in the Solaris 10 release. The change was based on the SUSv3 specification. The previous behavior was based on the initial SUSv2 specification, where \fBvsnprintf()\fR when \fIn\fR = 0 returns an unspecified value less than 1.