tar.c

unix v7是最后一个广泛发布的研究型UNIX版本

#include <stdio.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/dir.h>
#include <signal.h>

char	*sprintf();
char	*strcat();
daddr_t	bsrch();
#define TBLOCK	512
#define NBLOCK	20
#define NAMSIZ	100
union hblock {
	char dummy[TBLOCK];
	struct header {
		char name[NAMSIZ];
		char mode[8];
		char uid[8];
		char gid[8];
		char size[12];
		char mtime[12];
		char chksum[8];
		char linkflag;
		char linkname[NAMSIZ];
	} dbuf;
} dblock, tbuf[NBLOCK];

struct linkbuf {
	ino_t	inum;
	dev_t	devnum;
	int	count;
	char	pathname[NAMSIZ];
	struct	linkbuf *nextp;
} *ihead;

struct stat stbuf;

int	rflag, xflag, vflag, tflag, mt, cflag, mflag;
int	term, chksum, wflag, recno, first, linkerrok;
int	freemem = 1;
int	nblock = 1;

daddr_t	low;
daddr_t	high;

FILE	*tfile;
char	tname[] = "/tmp/tarXXXXXX";


char	*usefile;
char	magtape[]	= "/dev/mt1";

char	*malloc();

main(argc, argv)
int	argc;
char	*argv[];
{
	char *cp;
	int onintr(), onquit(), onhup(), onterm();

	if (argc < 2)
		usage();

	tfile = NULL;
	usefile =  magtape;
	argv[argc] = 0;
	argv++;
	for (cp = *argv++; *cp; cp++) 
		switch(*cp) {
		case 'f':
			usefile = *argv++;
			if (nblock == 1)
				nblock = 0;
			break;
		case 'c':
			cflag++;
			rflag++;
			break;
		case 'u':
			mktemp(tname);
			if ((tfile = fopen(tname, "w")) == NULL) {
				fprintf(stderr, "Tar: cannot create temporary file (%s)\n", tname);
				done(1);
			}
			fprintf(tfile, "!!!!!/!/!/!/!/!/!/! 000\n");
			/* FALL THROUGH */
		case 'r':
			rflag++;
			if (nblock != 1 && cflag == 0) {
noupdate:
				fprintf(stderr, "Tar: Blocked tapes cannot be updated (yet)\n");
				done(1);
			}
			break;
		case 'v':
			vflag++;
			break;
		case 'w':
			wflag++;
			break;
		case 'x':
			xflag++;
			break;
		case 't':
			tflag++;
			break;
		case 'm':
			mflag++;
			break;
		case '-':
			break;
		case '0':
		case '1':
			magtape[7] = *cp;
			usefile = magtape;
			break;
		case 'b':
			nblock = atoi(*argv++);
			if (nblock > NBLOCK || nblock <= 0) {
				fprintf(stderr, "Invalid blocksize. (Max %d)\n", NBLOCK);
				done(1);
			}
			if (rflag && !cflag)
				goto noupdate;
			break;
		case 'l':
			linkerrok++;
			break;
		default:
			fprintf(stderr, "tar: %c: unknown option\n", *cp);
			usage();
		}

	if (rflag) {
		if (cflag && tfile != NULL) {
			usage();
			done(1);
		}
		if (signal(SIGINT, SIG_IGN) != SIG_IGN)
			signal(SIGINT, onintr);
		if (signal(SIGHUP, SIG_IGN) != SIG_IGN)
			signal(SIGHUP, onhup);
		if (signal(SIGQUIT, SIG_IGN) != SIG_IGN)
			signal(SIGQUIT, onquit);
/*
		if (signal(SIGTERM, SIG_IGN) != SIG_IGN)
			signal(SIGTERM, onterm);
*/
		if (strcmp(usefile, "-") == 0) {
			if (cflag == 0) {
				fprintf(stderr, "Can only create standard output archives\n");
				done(1);
			}
			mt = dup(1);
			nblock = 1;
		}
		else if ((mt = open(usefile, 2)) < 0) {
			if (cflag == 0 || (mt =  creat(usefile, 0666)) < 0) {
				fprintf(stderr, "tar: cannot open %s\n", usefile);
				done(1);
			}
		}
		if (cflag == 0 && nblock == 0)
			nblock = 1;
		dorep(argv);
	}
	else if (xflag)  {
		if (strcmp(usefile, "-") == 0) {
			mt = dup(0);
			nblock = 1;
		}
		else if ((mt = open(usefile, 0)) < 0) {
			fprintf(stderr, "tar: cannot open %s\n", usefile);
			done(1);
		}
		doxtract(argv);
	}
	else if (tflag) {
		if (strcmp(usefile, "-") == 0) {
			mt = dup(0);
			nblock = 1;
		}
		else if ((mt = open(usefile, 0)) < 0) {
			fprintf(stderr, "tar: cannot open %s\n", usefile);
			done(1);
		}
		dotable();
	}
	else
		usage();
	done(0);
}

usage()
{
	fprintf(stderr, "tar: usage  tar -{txru}[cvfblm] [tapefile] [blocksize] file1 file2...\n");
	done(1);
}

dorep(argv)
char	*argv[];
{
	register char *cp, *cp2;
	char wdir[60];

	if (!cflag) {
		getdir();
		do {
			passtape();
			if (term)
				done(0);
			getdir();
		} while (!endtape());
		if (tfile != NULL) {
			char buf[200];

			strcat(buf, "sort +0 -1 +1nr ");
			strcat(buf, tname);
			strcat(buf, " -o ");
			strcat(buf, tname);
			sprintf(buf, "sort +0 -1 +1nr %s -o %s; awk '$1 != prev {print; prev=$1}' %s >%sX;mv %sX %s",
				tname, tname, tname, tname, tname, tname);
			fflush(tfile);
			system(buf);
			freopen(tname, "r", tfile);
			fstat(fileno(tfile), &stbuf);
			high = stbuf.st_size;
		}
	}

	getwdir(wdir);
	while (*argv && ! term) {
		cp2 = *argv;
		for (cp = *argv; *cp; cp++)
			if (*cp == '/')
				cp2 = cp;
		if (cp2 != *argv) {
			*cp2 = '\0';
			chdir(*argv);
			*cp2 = '/';
			cp2++;
		}
		putfile(*argv++, cp2);
		chdir(wdir);
	}
	putempty();
	putempty();
	flushtape();
	if (linkerrok == 1)
		for (; ihead != NULL; ihead = ihead->nextp)
			if (ihead->count != 0)
				fprintf(stderr, "Missing links to %s\n", ihead->pathname);
}

endtape()
{
	if (dblock.dbuf.name[0] == '\0') {
		backtape();
		return(1);
	}
	else
		return(0);
}

getdir()
{
	register struct stat *sp;
	int i;

	readtape( (char *) &dblock);
	if (dblock.dbuf.name[0] == '\0')
		return;
	sp = &stbuf;
	sscanf(dblock.dbuf.mode, "%o", &i);
	sp->st_mode = i;
	sscanf(dblock.dbuf.uid, "%o", &i);
	sp->st_uid = i;
	sscanf(dblock.dbuf.gid, "%o", &i);
	sp->st_gid = i;
	sscanf(dblock.dbuf.size, "%lo", &sp->st_size);
	sscanf(dblock.dbuf.mtime, "%lo", &sp->st_mtime);
	sscanf(dblock.dbuf.chksum, "%o", &chksum);
	if (chksum != checksum()) {
		fprintf(stderr, "directory checksum error\n");
		done(2);
	}
	if (tfile != NULL)
		fprintf(tfile, "%s %s\n", dblock.dbuf.name, dblock.dbuf.mtime);
}

passtape()
{
	long blocks;
	char buf[TBLOCK];

	if (dblock.dbuf.linkflag == '1')
		return;
	blocks = stbuf.st_size;
	blocks += TBLOCK-1;
	blocks /= TBLOCK;

	while (blocks-- > 0)
		readtape(buf);
}

putfile(longname, shortname)
char *longname;
char *shortname;
{
	int infile;
	long blocks;
	char buf[TBLOCK];
	register char *cp, *cp2;
	struct direct dbuf;
	int i, j;

	infile = open(shortname, 0);
	if (infile < 0) {
		fprintf(stderr, "tar: %s: cannot open file\n", longname);
		return;
	}

	fstat(infile, &stbuf);

	if (tfile != NULL && checkupdate(longname) == 0) {
		close(infile);
		return;
	}
	if (checkw('r', longname) == 0) {
		close(infile);
		return;
	}

	if ((stbuf.st_mode & S_IFMT) == S_IFDIR) {
		for (i = 0, cp = buf; *cp++ = longname[i++];);
		*--cp = '/';
		cp++;
		i = 0;
		chdir(shortname);
		while (read(infile, (char *)&dbuf, sizeof(dbuf)) > 0 && !term) {
			if (dbuf.d_ino == 0) {
				i++;
				continue;
			}
			if (strcmp(".", dbuf.d_name) == 0 || strcmp("..", dbuf.d_name) == 0) {
				i++;
				continue;
			}
			cp2 = cp;
			for (j=0; j < DIRSIZ; j++)
				*cp2++ = dbuf.d_name[j];
			*cp2 = '\0';
			close(infile);
			putfile(buf, cp);
			infile = open(".", 0);
			i++;
			lseek(infile, (long) (sizeof(dbuf) * i), 0);
		}
		close(infile);
		chdir("..");
		return;
	}
	if ((stbuf.st_mode & S_IFMT) != S_IFREG) {
		fprintf(stderr, "tar: %s is not a file. Not dumped\n", longname);
		return;
	}

	tomodes(&stbuf);

	cp2 = longname;
	for (cp = dblock.dbuf.name, i=0; (*cp++ = *cp2++) && i < NAMSIZ; i++);
	if (i >= NAMSIZ) {
		fprintf(stderr, "%s: file name too long\n", longname);
		close(infile);
		return;
	}

	if (stbuf.st_nlink > 1) {
		struct linkbuf *lp;
		int found = 0;

		for (lp = ihead; lp != NULL; lp = lp->nextp) {
			if (lp->inum == stbuf.st_ino && lp->devnum == stbuf.st_dev) {
				found++;
				break;
			}
		}
		if (found) {
			strcpy(dblock.dbuf.linkname, lp->pathname);
			dblock.dbuf.linkflag = '1';
			sprintf(dblock.dbuf.chksum, "%6o", checksum());
			writetape( (char *) &dblock);
			if (vflag) {
				fprintf(stderr, "a %s ", longname);
				fprintf(stderr, "link to %s\n", lp->pathname);
			}
			lp->count--;
			close(infile);
			return;
		}
		else {
			lp = (struct linkbuf *) malloc(sizeof(*lp));
			if (lp == NULL) {
				if (freemem) {
					fprintf(stderr, "Out of memory. Link information lost\n");
					freemem = 0;
				}
			}
			else {
				lp->nextp = ihead;
				ihead = lp;
				lp->inum = stbuf.st_ino;
				lp->devnum = stbuf.st_dev;
				lp->count = stbuf.st_nlink - 1;
				strcpy(lp->pathname, longname);
			}
		}
	}

	blocks = (stbuf.st_size + (TBLOCK-1)) / TBLOCK;
	if (vflag) {
		fprintf(stderr, "a %s ", longname);
		fprintf(stderr, "%ld blocks\n", blocks);
	}
	sprintf(dblock.dbuf.chksum, "%6o", checksum());
	writetape( (char *) &dblock);

	while ((i = read(infile, buf, TBLOCK)) > 0 && blocks > 0) {
		writetape(buf);
		blocks--;
	}
	close(infile);
	if (blocks != 0 || i != 0)
		fprintf(stderr, "%s: file changed size\n", longname);
	while (blocks-- >  0)
		putempty();
}



doxtract(argv)
char	*argv[];
{
	long blocks, bytes;
	char buf[TBLOCK];
	char **cp;
	int ofile;

	for (;;) {
		getdir();
		if (endtape())
			break;

		if (*argv == 0)
			goto gotit;

		for (cp = argv; *cp; cp++)
			if (prefix(*cp, dblock.dbuf.name))
				goto gotit;
		passtape();
		continue;

gotit:
		if (checkw('x', dblock.dbuf.name) == 0) {
			passtape();
			continue;