VSNPRINTF

Section: Basic C Library Functions (9)
Updated: February 2011
Index Return to Main Contents

NAME

vsnprintf - Format a string and place it in a buffer

SYNOPSIS

int vsnprintf(char * buf, size_t size, const char * fmt, va_list args);

ARGUMENTS

buf

: The buffer to place the result into

size

: The size of the buffer, including the trailing null space

fmt

: The format string to use

args

: Arguments for the format string

DESCRIPTION

This function follows C99 vsnprintf, but has some extensions: pS output the name of a text symbol with offset ps output the name of a text symbol without offset pF output the name of a function pointer with its offset pf output the name of a function pointer without its offset pR output the address range in a struct resource with decoded flags pr output the address range in a struct resource with raw flags pM output a 6-byte MAC address with colons pm output a 6-byte MAC address without colons pI4 print an IPv4 address without leading zeros pi4 print an IPv4 address with leading zeros pI6 print an IPv6 address with colons pi6 print an IPv6 address without colons pI6c print an IPv6 address as specified by

HTTP

//tools.ietf.org/html/draft-ietf-6man-text-addr-representation-00 pU[bBlL] print a UUID/GUID in big or little endian using lower or upper case. n is ignored

The return value is the number of characters which would be generated for the given input, excluding the trailing '\0', as per ISO C99. If you want to have the exact number of characters written into buf as return value (not including the trailing '\0'), use vscnprintf. If the return is greater than or equal to size, the resulting string is truncated.