synctree.c

minix软件源代码

				arg0, Spath);
			because();
			return;
		}
		printf("Special file %s created\n", Spath);
		break;
#ifdef S_IFLNK
	case S_IFLNK:
		if (interact && !update) {
			printf("Install %s -> %s", Spath, Slnkpth);
			if (!ask('n')) { order(CANCEL); return; }
		}
		if (symlink(Slnkpth, Spath) < 0) {
			fprintf(stderr, "%s: Can't create symlink %s",
				arg0, Spath);
			because();
			return;
		}
		printf("%s %s -> %s\n",
			forced_update ? "Updated:  " : "Installed:",
			Spath, Slnkpth);
		break;
#endif
	case S_IFREG:
		if (interact && !update) {
			printf("Install %s", Spath);
			if (!ask('n')) { order(CANCEL); return; }
		}
		order(CAT);
		if (answer() != DATA) return;

		busy= 1;
		if ((f= creat(Spath, backup ? 0644 : Sst.st_mode&07777)) < 0) {
			busy= 0;
			fprintf(stderr, "%s: Can't create %s", arg0, Spath);
			because();
		}

		while ((n= receive(buf, sizeof(buf)))>0) {
			if (f >= 0 && write(f, buf, n) != n) {
				fprintf(stderr, "%s: Write error on %s",
					arg0, Spath);
				because();
				close(f); f= -1;
			}
		}
		if (n < 0) {
			fprintf(stderr, "%s: Slave read err on %s\n",
				arg0, Spath);
		}
		if (f >= 0) close(f);
		if (n < 0 || f < 0) { makeold(); busy= 0; return; }
		busy= 0;
		printf("%s %s\n",
			forced_update ?
				Sst.st_mtime < st.st_mtime ? "Restored: " :
					"Updated:  " :
				"Installed:",
			Spath
		);
		break;
	default:
		fprintf(stderr,
			"%s: Won't add file with strange mode %05o: %s\n",
			arg0, Sst.st_mode, Spath);
		order(CANCEL);
		return;
	}
	setmodes(1);
}

static int delete(update) int update;
/* Delete path. */
{
	int forced_update= force && update;

	if (S_ISDIR(st.st_mode)) {
		if (install) return 0;
		if (!force) {
			printf("Delete dir %s", path);
			if (!ask('n')) return 0;
		}
		if (!removedir(path)) { ex= 1; return 0; }
		if (!forced_update) printf("Directory %s deleted.\n", path);
		return 1;
	}

	if (install && !update) return 0;

	if (!force) {
		printf("Delete %s", path);
		if (!ask((interact && !update) ? 'n' : 'y')) return 0;
	}

	if (unlink(path)<0) {
		fprintf(stderr, "Can't delete %s", path);
		because();
		return 0;
	}
	cancellink();
	if (!forced_update) printf("Deleted:   %s\n", path);
	return 1;
}

static int different()
/* Return true iff path and Spath are different. */
{
	if (! ( (linkpath == nil && Slinkpath == nil)
		|| (linkpath != nil && Slinkpath != nil
			&& strcmp(linkpath, Slinkpath) == 0)
	)) {
		linkpath= Slinkpath;
		return 1;
	}

	if ((st.st_mode & S_IFMT) != (Sst.st_mode & S_IFMT)) return 1;

	switch (st.st_mode & S_IFMT) {
	case S_IFDIR:
		return 0;
	case S_IFBLK:
	case S_IFCHR:
		return st.st_rdev != Sst.st_rdev;
	case S_IFREG:
		if (install) return Sst.st_mtime > st.st_mtime;
		return st.st_size != Sst.st_size
			|| st.st_mtime != Sst.st_mtime;
	case S_IFIFO:	return 0;
#ifdef S_IFLNK
	case S_IFLNK:	return strcmp(lnkpth, Slnkpth) != 0;
#endif
	default:	return 1;
	}
}

static void compare()
/* See if path and Spath are same. */
{
	if (different()) {
		if (!force) {
			printf("%sing %s (delete + add)\n",
				Sst.st_mtime < st.st_mtime ? "Restor" : "Updat",
				path);
		}
		if (delete(1)) add(1);
	} else {
		if (!install) setmodes(0);

		if (S_ISDIR(st.st_mode)) {
			order(ENTER);
			enter();
		}
	}
}

static int done= 0, Sdone= 0;

static enum action { ADD, COMPARE, DELETE } action()
/* Look at path's of master and slave, compare them alphabetically to see
 * who is ahead of who, then tell what is to be done.
 */
{
	int c;
	char *Sp, *p;

	if (done) return ADD;		/* Slave still has names. */
	if (Sdone) return DELETE;	/* Master has too many names. */

	/* Compare paths.  Let "a/a" come before "a.a". */
	Sp= Spath;
	p= path;
	while (*Sp == *p && *Sp != 0) { Sp++; p++; }
	if (*Sp == '/') return ADD;
	if (*p == '/') return DELETE;
	return (c= strcmp(Sp, p)) == 0 ? COMPARE : c < 0 ? ADD : DELETE;
}

static void master()
/* Synchronise file tree to that of its slave. */
{
	enum action a= COMPARE;	/* Trick first advances. */

	umask(backup ? 0022 : 0000);

	signal(SIGPIPE, SIG_IGN);
	signal(SIGHUP, bail_out);
	signal(SIGINT, bail_out);
	signal(SIGTERM, bail_out);

	while (!done || !Sdone) {
		if (!Sdone && (a == ADD || a == COMPARE)) {
			/* Slave advances. */
			order(ADVANCE);
			switch (answer()) {
			case PATH:
				Slinkpath= nil;
				receive(Spath, sizeof(Spath));
				recstat(&Sst);
				break;
			case LINK:
				receive(Slnkpth, sizeof(Slnkpth));
				Slinkpath= Slnkpth;
				receive(Spath, sizeof(Spath));
				recstat(&Sst);
				break;
			case SYMLINK:
				Slinkpath= nil;
				receive(Slnkpth, sizeof(Slnkpth));
				receive(Spath, sizeof(Spath));
				recstat(&Sst);
				break;
			case DONE:
				Sdone= 1;
				break;
			default:
				fprintf(stderr,
					"%s: Strange answer from slave.\n",
					arg0);
				exit(1);
			}
		}
		if (!done && (a == COMPARE || a == DELETE)) {
			/* Master advances. */
			if (!advance()) done= 1;
		}

		if (done && Sdone) break;

		switch (a= action()) {
		case ADD:	/* Spath exists, path doesn't, add? */
			add(0);
			break;
		case COMPARE:	/* They both exist, are they the same? */
			compare();
			break;
		case DELETE:	/* path exists, Spath doesn't, delete? */
			delete(0);
		}
		fflush(stdout);	/* Don't keep user in suspense. */
	}
	order(ex == 0 ? DIE : DIE_BAD);
}

static void mediator()
/* Sits at the local machine and passes orders from master to slave, both
 * on remote machines.  Only diagnostics and questions are handled.
 */
{
	enum orders req;

	for (;;) {
		switch (req= request()) {
		case DIE_BAD:
			ex= 1;
			/*FALL THROUGH*/
		case DIE:
			order(DIE);
			return;
		case POSITIVE:
			order(ask('y') ? PASS_YES : PASS_NO);
			break;
		case NEGATIVE:
			order(ask('n') ? PASS_YES : PASS_NO);
			break;
		default:
			order(req);
		}
	}
}

#define P_EXIT		1	/* Make sure process doesn't return. */
#define P_SHADOW	2	/* Always use exec on 68000. */

static void startprocess(proc, machine, path, p_flags)
	void (*proc)(); char *machine, *path; int p_flags;
{
	char *argv[10], **argp= argv;
	char flags[10], *pfl= flags;

	if (machine != nil) {
		char *u= machine, *m;

		*argp++ = "rsh";
		if ((m= strchr(machine, '@')) != nil) {
			*m++ = 0;
			*argp++ = "-l";
			*argp++ = u;
			machine= m;
		}
		*argp++ = machine;
	} else
	/* Without this check it would run like a pig on an non MMU 68000: */
	if (!(USE_SHADOWING && p_flags & P_SHADOW)) {
		if (chdir(path) < 0) {
			if (proc != master || errno != ENOENT
						|| mkdir(path, 0700) < 0)
				perrx(path);
			if (chdir(path) < 0) perrx(path);
			printf("Destination directory %s created\n", path);
		}
		isvisible(path);
		isbackup(proc == slave);
		(*proc)();
		if (p_flags & P_EXIT) exit(ex);
		return;
	}
	*argp++ = SYNCNAME;
	*pfl++ = '-';
	if (interact) *pfl++ = 'i';
	if (install) *pfl++ = 'u';
	if (force) *pfl++ = 'f';
	*pfl= 0;
	*argp++ = flags;
	*argp++ = proc == slave ? SLAVENAME : MASTERNAME;
	*argp++ = path;
	*argp++ = nil;
#ifdef DEBUG
	fprintf(stderr, "execlp(");
	for (argp= argv; *argp != nil; argp++) fprintf(stderr, "%s, ", *argp);
	fprintf(stderr, "nil);\n");
#endif
	execvp(argv[0], argv);
	perrx(argv[0]);
}

void splitcolon(path, amach, adir) char *path, **amach, **adir;
{
	char *dir= path;

	for (;;) {
		if (*dir == ':') {
			*dir++ = 0;
			*amach= path;
			*adir= dir;
			break;
		}
		if (*dir == 0 || *dir == '/') {
			*amach= nil;
			*adir= path;
			break;
		}
		dir++;
	}
}

static void Usage()
{
	fprintf(stderr,
	    "Usage: %s [-iuf] [[user@]machine:]dir1 [[user@]machine:]dir2\n",
		arg0);
	exit(1);
}

main(argc, argv) int argc; char **argv;
{
	char *s_mach, *s_dir;
	char *m_mach, *m_dir;
	int m2s[2], s2m[2], m2m[2];
	int s_pid= 0, m_pid= 0;
	int r;

	if ((arg0= strrchr(argv[0], '/')) == nil) arg0= argv[0]; else arg0++;

	while (argc>1 && argv[1][0] == '-') {
		char *f= argv[1]+1;

		while (*f != 0) {
			switch (*f++) {
			case 'i':	interact= 1; break;
			case 'u':	install= 1; break;
			case 'f':	force= 1; break;
			default:	Usage();
			}
		}
		argc--;
		argv++;
	}

	if (argc != 3) Usage();

	if (strcmp(argv[1], SLAVENAME) == 0) {
		arg0= "Slave";
		splitcolon(argv[2], &s_mach, &s_dir);
		startprocess(slave, s_mach, s_dir, P_EXIT);
	} else
	if (strcmp(argv[1], MASTERNAME) == 0) {
		arg0= "Master";
		splitcolon(argv[2], &m_mach, &m_dir);
		startprocess(master, m_mach, m_dir, P_EXIT);
	}

	splitcolon(argv[1], &s_mach, &s_dir);
	splitcolon(argv[2], &m_mach, &m_dir);

	/* How difficult can plumbing be? */
	if (pipe(m2s) < 0 || pipe(s2m) < 0) perrx("pipe()");

	if (m_mach == nil) {
		/* synctree [machine:]dir1 dir2 */
		switch (s_pid= fork()) {
		case -1:
			perrx("fork()");
		case 0:
			dup2(m2s[0], 0); close(m2s[0]); close(m2s[1]);
			dup2(s2m[1], 1); close(s2m[0]); close(s2m[1]);
			arg0= "Slave";
			startprocess(slave, s_mach, s_dir, P_EXIT|P_SHADOW);
		}
		chan[0]= s2m[0]; close(s2m[1]);
		chan[1]= m2s[1]; close(m2s[0]);
		startprocess(master, m_mach, m_dir, 0);
	} else
	if (s_mach == nil) {
		/* synctree dir1 machine:dir2 */
		switch (m_pid= fork()) {
		case -1:
			perrx("fork()");
		case 0:
			dup2(s2m[0], 0); close(s2m[0]); close(s2m[1]);
			dup2(m2s[1], 1); close(m2s[0]); close(m2s[1]);
			arg0= "Master";
			startprocess(master, m_mach, m_dir, P_EXIT|P_SHADOW);
		}
		chan[0]= m2s[0]; close(m2s[1]);
		chan[1]= s2m[1]; close(s2m[0]);
		startprocess(slave, s_mach, s_dir, 0);
	} else {
		/* synctree machine1:dir1 machine2:dir2 */
		if (pipe(m2m) < 0) perrx(pipe);

		switch (s_pid= fork()) {
		case -1:
			perrx("fork()");
		case 0:
			dup2(m2s[0], 0); close(m2s[0]); close(m2s[1]);
			dup2(s2m[1], 1); close(s2m[0]); close(s2m[1]);
			close(m2m[0]); close(m2m[1]);
			arg0= "Slave";
			startprocess(slave, s_mach, s_dir, P_EXIT|P_SHADOW);
		}

		switch (m_pid= fork()) {
		case -1:
			perrx("fork()");
		case 0:
			dup2(s2m[0], 0); close(s2m[0]); close(s2m[1]);
			close(m2s[0]); close(m2s[1]);
			dup2(m2m[1], 1); close(m2m[0]); close(m2m[1]);
			arg0= "Master";
			startprocess(master, m_mach, m_dir, P_EXIT|P_SHADOW);
		}
		close(s2m[0]); close(s2m[1]);
		chan[0]= m2m[0]; close(m2m[1]);
		chan[1]= m2s[1]; close(m2s[0]);
		mediator();
	}
	close(chan[0]);
	close(chan[1]);

	alarm(15); /* Don't wait(2) forever. */

	while (s_pid != 0 || m_pid != 0) {
		if ((r= wait((int *) nil)) < 0) perrx("wait()");
		if (r == s_pid) s_pid= 0;
		if (r == m_pid) m_pid= 0;
	}
	exit(ex);
}