CrossWorks for ARM User Guide

vscanf returns the value of the macro EOF if an input failure occurs before anyconversion. Otherwise, vscanf returns the number of input items assigned, which canbe fewer than provided for, or even zero, in the event of an early matching failure.NotesPortabilityvscanf is equivalent to scanf with the variable argument list replaced by arg.vscanf conforms to ISO/IEC 9899:1990 (C90) and ISO/IEC 9899:1999 (C99).See Also Formatted input control strings (page 285)vsnprintfSynopsisDescriptionNotesPortability#include int vsnprintf(char *s, size_t n, const char *format, va_list arg);vsnprintf writes to the string pointed to by s under control of the string pointed to byformat that specifies how subsequent arguments are converted for output. Beforecalling vsnprintf, arg must be initialized by the va_start macro (and possiblysubsequent va_arg calls). vsnprintf does not invoke the va_end macro.If n is zero, nothing is written, and s can be a null pointer. Otherwise, output charactersbeyond the n-1st are discarded rather than being written to the array, and a nullcharacter is written at the end of the characters actually written into the array. A nullcharacter is written at the end of the conversion; it is not counted as part of the returnedvalue.If there are insufficient arguments for the format, the behavior is undefined. If theformat is exhausted while arguments remain, the excess arguments are evaluated butare otherwise ignored.If copying takes place between objects that overlap, the behavior is undefined.vsnprintf returns the number of characters that would have been written had n beensufficiently large, not counting the terminating null character, or a negative value if anencoding error occurred. Thus, the null-terminated output has been completelywritten if and only if the returned value is nonnegative and less than n.vsnprintf is equivalent to snprintf with the variable argument list replaced by arg.vsnprintf conforms to ISO/IEC 9899:1990 (C90) and ISO/IEC 9899:1999 (C99).See Also Formatted output control strings (page 281)vsprintfSynopsis#include int vsprintf(char *s, const char *format, va_list arg);Chapter 28 - Input/output functions293