Guardian C Library Calls Reference Manual

Reference to Library Calls

Guardian TNS C Library Calls Reference Manual—128833 3-233

vfprintf

The vfprintf function writes formatted data to a file opened for ANSI I/O, extracting the

data values from a variable argument list.

stream

denotes a file opened for ANSI I/O.

format

points to a string that contains characters and conversion specifiers, which indicate

how to format the values of the arguments denoted by ap. Refer to “fprintf” on

page 3-51 for a description of format and conversion specifiers.

is a variable of type va_list that has been initialized by a previous invocation of

va_start (and possibly invocations of va_arg as well).

Return Value

is the number of characters output if the operation is successful; otherwise, vfprintf

returns a negative value.

Usage Guidelines

•

Note that vfprintf requires two headers, <stdargh> and <stdioh>.

•

The vfprintf function does not call the va_end function.

#include <stdargh>

#include <stdioh>

int vfprintf(FILE *stream, const char *format, va_list ap);