fmtprint.c

这是一个同样来自贝尔实验室的和UNIX有着渊源的操作系统, 其简洁的设计和实现易于我们学习和理解

#include <u.h>
#include <libc.h>
#include "fmtdef.h"

/*
 * format a string into the output buffer
 * designed for formats which themselves call fmt,
 * but ignore any width flags
 */
int
fmtprint(Fmt *f, char *fmt, ...)
{
	va_list va;
	int n;

	f->flags = 0;
	f->width = 0;
	f->prec = 0;
	VA_COPY(va, f->args);
	VA_END(f->args);
	va_start(f->args, fmt);
	n = dofmt(f, fmt);
	va_end(f->args);
	f->flags = 0;
	f->width = 0;
	f->prec = 0;
	VA_COPY(f->args,va);
	VA_END(va);
	if(n >= 0)
		return 0;
	return n;
}