debug.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 <auth.h>
#include <bio.h>
#include "imap4d.h"

void
debuglog(char *fmt, ...)
{
	va_list arg;
	static int logfd;

	if(debug == 0)
		return;
	if(logfd == 0)
		logfd = open("/sys/log/imap4d", OWRITE);
	if(logfd > 0){
		va_start(arg, fmt);
		fprint(logfd, "%s: ", username);
		vfprint(logfd, fmt, arg);
		va_end(arg);
	}
}

void
boxVerify(Box *box)
{
	Msg *m;
	ulong seq, uid, recent;

	if(box == nil)
		return;
	recent = 0;
	seq = 0;
	uid = 0;
	for(m = box->msgs; m != nil; m = m->next){
		if(m->seq == 0)
			fprint(2, "m->seq == 0: m->seq=%lud\n", m->seq);
		else if(m->seq <= seq)
			fprint(2, "m->seq=%lud out of order: last=%lud\n", m->seq, seq);
		seq = m->seq;

		if(m->uid == 0)
			fprint(2, "m->uid == 0: m->seq=%lud\n", m->seq);
		else if(m->uid <= uid)
			fprint(2, "m->uid=%lud out of order: last=%lud\n", m->uid, uid);
		uid = m->uid;

		if(m->flags & MRecent)
			recent++;
	}
	if(seq != box->max)
		fprint(2, "max=%lud, should be %lud\n", box->max, seq);
	if(uid >= box->uidnext)
		fprint(2, "uidnext=%lud, maxuid=%lud\n", box->uidnext, uid);
	if(recent != box->recent)
		fprint(2, "recent=%lud, should be %lud\n", box->recent, recent);
}

void
openfiles(void)
{
	Dir *d;
	int i;

	for(i = 0; i < 20; i++){
		d = dirfstat(i);
		if(d != nil){
			fprint(2, "fd[%d]='%s' type=%c dev=%d user='%s group='%s'\n", i, d->name, d->type, d->dev, d->uid, d->gid);
			free(d);
		}
	}
}

void
ls(char *file)
{
	Dir *d;
	int fd, i, nd;

	fd = open(file, OREAD);
	if(fd < 0)
		return;

	/*
	 * read box to find all messages
	 * each one has a directory, and is in numerical order
	 */
	d = dirfstat(fd);
	if(d == nil){
		close(fd);
		return;
	}
	if(!(d->mode & DMDIR)){
		fprint(2, "file %s\n", file);
		free(d);
		close(fd);
		return;
	}
	free(d);
	while((nd = dirread(fd, &d)) > 0){
		for(i = 0; i < nd; i++){
			fprint(2, "%s/%s %c\n", file, d[i].name, "-d"[(d[i].mode & DMDIR) == DMDIR]);
		}
		free(d);
	}
	close(fd);
}