commit - 4c00852c86097c9e96cb6f21a3a27a8be93306b2
commit + 1d620367bd070f2eae99a70f8537c701a737650a
blob - 42bdcd412730b8c2a97af82c3b57ef9e3042987f (mode 644)
blob + /dev/null
--- src/cmd/tar.C
+++ /dev/null
-/*
- * tar - `tape archiver', actually usable on any medium.
- * POSIX "ustar" compliant when extracting, and by default when creating.
- * this tar attempts to read and write multiple Tblock-byte blocks
- * at once to and from the filesystem, and does not copy blocks
- * around internally.
- */
-
-#include <u.h>
-#include <libc.h>
-#include <fcall.h> /* for %M */
-#include <libString.h>
-
-#define creat tar_creat
-
-/*
- * modified versions of those in libc.h; scans only the first arg for
- * keyletters and options.
- */
-#define TARGBEGIN {\
- __fixargv0(); if(!argv0) argv0=*argv; \
- argv++, argc--; \
- if (argv[0]) {\
- char *_args, *_argt;\
- Rune _argc;\
- _args = &argv[0][0];\
- _argc = 0;\
- while(*_args && (_args += chartorune(&_argc, _args)))\
- switch(_argc)
-#define TARGEND SET(_argt); USED(_argt); USED(_argc); USED(_args); argc--, argv++; } \
- USED(argv);USED(argc); }
-
-#define ROUNDUP(a, b) (((a) + (b) - 1)/(b))
-#define BYTES2TBLKS(bytes) ROUNDUP(bytes, Tblock)
-
-typedef vlong Off;
-typedef char *(*Refill)(int ar, char *bufs);
-
-enum { Stdin, Stdout, Stderr };
-enum { None, Toc, Xtract, Replace };
-enum {
- Tblock = 512,
- Nblock = 40, /* maximum blocksize */
- Dblock = 20, /* default blocksize */
- Namsiz = 100,
- Maxpfx = 155, /* from POSIX */
- Maxname = Namsiz + 1 + Maxpfx,
- DEBUG = 0,
-};
-
-/* POSIX link flags */
-enum {
- LF_PLAIN1 = '\0',
- LF_PLAIN2 = '0',
- LF_LINK = '1',
- LF_SYMLINK1 = '2',
- LF_SYMLINK2 = 's',
- LF_CHR = '3',
- LF_BLK = '4',
- LF_DIR = '5',
- LF_FIFO = '6',
- LF_CONTIG = '7',
- /* 'A' - 'Z' are reserved for custom implementations */
-};
-
-#define islink(lf) (isreallink(lf) || issymlink(lf))
-#define isreallink(lf) ((lf) == LF_LINK)
-#define issymlink(lf) ((lf) == LF_SYMLINK1 || (lf) == LF_SYMLINK2)
-
-typedef union {
- 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];
-
- /* rest are defined by POSIX's ustar format; see p1003.2b */
- char magic[6]; /* "ustar" */
- char version[2];
- char uname[32];
- char gname[32];
- char devmajor[8];
- char devminor[8];
- char prefix[Maxpfx]; /* if non-null, path= prefix "/" name */
-} Hdr;
-
-int debug;
-static int verb;
-static int posix = 1;
-static int creat;
-static int aruid;
-static int argid;
-static int relative;
-static int settime;
-static int verbose;
-
-static int nblock = Dblock;
-static char *usefile;
-static char origdir[Maxname*2];
-static Hdr *tpblk, *endblk;
-static Hdr *curblk;
-
-static void
-usage(void)
-{
- fprint(2, "usage: %s {txrc}[pPvRTugf] [archive] file1 file2...\n",
- argv0);
- exits("usage");
-}
-
-/*
- * block-buffer management
- */
-
-static void
-initblks(void)
-{
- free(tpblk);
- tpblk = malloc(Tblock * nblock);
- assert(tpblk != nil);
- endblk = tpblk + nblock;
-}
-
-static char *
-refill(int ar, char *bufs)
-{
- int i, n;
- unsigned bytes = Tblock * nblock;
- static int done, first = 1;
-
- if (done)
- return nil;
-
- /* try to size non-pipe input at first read */
- if (first && usefile) {
- first = 0;
- n = read(ar, bufs, bytes);
- if (n <= 0)
- sysfatal("error reading archive: %r");
- i = n;
- if (i % Tblock != 0) {
- fprint(2, "%s: archive block size (%d) error\n",
- argv0, i);
- exits("blocksize");
- }
- i /= Tblock;
- if (i != nblock) {
- nblock = i;
- fprint(2, "%s: blocking = %d\n", argv0, nblock);
- endblk = (Hdr *)bufs + nblock;
- bytes = n;
- }
- } else
- n = readn(ar, bufs, bytes);
- if (n == 0)
- sysfatal("unexpected EOF reading archive");
- else if (n < 0)
- sysfatal("error reading archive: %r");
- else if (n%Tblock != 0)
- sysfatal("partial block read from archive");
- if (n != bytes) {
- done = 1;
- memset(bufs + n, 0, bytes - n);
- }
- return bufs;
-}
-
-static Hdr *
-getblk(int ar, Refill rfp)
-{
- if (curblk == nil || curblk >= endblk) { /* input block exhausted? */
- if (rfp != nil && (*rfp)(ar, (char *)tpblk) == nil)
- return nil;
- curblk = tpblk;
- }
- return curblk++;
-}
-
-static Hdr *
-getblkrd(int ar)
-{
- return getblk(ar, refill);
-}
-
-static Hdr *
-getblke(int ar)
-{
- return getblk(ar, nil);
-}
-
-static Hdr *
-getblkz(int ar)
-{
- Hdr *hp = getblke(ar);
-
- if (hp != nil)
- memset(hp, 0, Tblock);
- return hp;
-}
-
-/*
- * how many block buffers are available, starting at the address
- * just returned by getblk*?
- */
-static int
-gothowmany(int max)
-{
- int n = endblk - (curblk - 1);
-
- return n > max? max: n;
-}
-
-/*
- * indicate that one is done with the last block obtained from getblke
- * and it is now available to be written into the archive.
- */
-static void
-putlastblk(int ar)
-{
- unsigned bytes = Tblock * nblock;
-
- /* if writing end-of-archive, aid compression (good hygiene too) */
- if (curblk < endblk)
- memset(curblk, 0, (char *)endblk - (char *)curblk);
- if (write(ar, tpblk, bytes) != bytes)
- sysfatal("error writing archive: %r");
-}
-
-static void
-putblk(int ar)
-{
- if (curblk >= endblk)
- putlastblk(ar);
-}
-
-static void
-putbackblk(int ar)
-{
- curblk--;
- USED(ar);
-}
-
-static void
-putreadblks(int ar, int blks)
-{
- curblk += blks - 1;
- USED(ar);
-}
-
-static void
-putblkmany(int ar, int blks)
-{
- curblk += blks - 1;
- putblk(ar);
-}
-
-/*
- * common routines
- */
-
-/* modifies hp->chksum */
-long
-chksum(Hdr *hp)
-{
- int n = Tblock;
- long i = 0;
- uchar *cp = (uchar*)hp;
-
- memset(hp->chksum, ' ', sizeof hp->chksum);
- while (n-- > 0)
- i += *cp++;
- return i;
-}
-
-static int
-isustar(Hdr *hp)
-{
- return strcmp(hp->magic, "ustar") == 0;
-}
-
-/*
- * s is at most n bytes long, but need not be NUL-terminated.
- * if shorter than n bytes, all bytes after the first NUL must also
- * be NUL.
- */
-static int
-strnlen(char *s, int n)
-{
- return s[n - 1] != '\0'? n: strlen(s);
-}
-
-/* set fullname from header */
-static char *
-name(Hdr *hp)
-{
- int pfxlen, namlen;
- static char fullname[Maxname + 1];
-
- namlen = strnlen(hp->name, sizeof hp->name);
- if (hp->prefix[0] == '\0' || !isustar(hp)) { /* old-style name? */
- memmove(fullname, hp->name, namlen);
- fullname[namlen] = '\0';
- return fullname;
- }
-
- /* name is in two pieces */
- pfxlen = strnlen(hp->prefix, sizeof hp->prefix);
- memmove(fullname, hp->prefix, pfxlen);
- fullname[pfxlen] = '/';
- memmove(fullname + pfxlen + 1, hp->name, namlen);
- fullname[pfxlen + 1 + namlen] = '\0';
- return fullname;
-}
-
-static int
-isdir(Hdr *hp)
-{
- /* the mode test is ugly but sometimes necessary */
- return hp->linkflag == LF_DIR ||
- strrchr(name(hp), '\0')[-1] == '/' ||
- (strtoul(hp->mode, nil, 8)&0170000) == 040000;
-}
-
-static int
-eotar(Hdr *hp)
-{
- return name(hp)[0] == '\0';
-}
-
-static Hdr *
-readhdr(int ar)
-{
- long hdrcksum;
- Hdr *hp;
-
- hp = getblkrd(ar);
- if (hp == nil)
- sysfatal("unexpected EOF instead of archive header");
- if (eotar(hp)) /* end-of-archive block? */
- return nil;
- hdrcksum = strtoul(hp->chksum, nil, 8);
- if (chksum(hp) != hdrcksum)
- sysfatal("bad archive header checksum: name %.64s...",
- hp->name);
- return hp;
-}
-
-/*
- * tar r[c]
- */
-
-/*
- * if name is longer than Namsiz bytes, try to split it at a slash and fit the
- * pieces into hp->prefix and hp->name.
- */
-static int
-putfullname(Hdr *hp, char *name)
-{
- int namlen, pfxlen;
- char *sl, *osl;
- String *slname = nil;
-
- if (isdir(hp)) {
- slname = s_new();
- s_append(slname, name);
- s_append(slname, "/"); /* posix requires this */
- name = s_to_c(slname);
- }
-
- namlen = strlen(name);
- if (namlen <= Namsiz) {
- strncpy(hp->name, name, Namsiz);
- hp->prefix[0] = '\0'; /* ustar paranoia */
- return 0;
- }
-
- if (!posix || namlen > Maxname) {
- fprint(2, "%s: name too long for tar header: %s\n",
- argv0, name);
- return -1;
- }
- /*
- * try various splits until one results in pieces that fit into the
- * appropriate fields of the header. look for slashes from right
- * to left, in the hopes of putting the largest part of the name into
- * hp->prefix, which is larger than hp->name.
- */
- sl = strrchr(name, '/');
- while (sl != nil) {
- pfxlen = sl - name;
- if (pfxlen <= sizeof hp->prefix && namlen-1 - pfxlen <= Namsiz)
- break;
- osl = sl;
- *osl = '\0';
- sl = strrchr(name, '/');
- *osl = '/';
- }
- if (sl == nil) {
- fprint(2, "%s: name can't be split to fit tar header: %s\n",
- argv0, name);
- return -1;
- }
- *sl = '\0';
- strncpy(hp->prefix, name, sizeof hp->prefix);
- *sl++ = '/';
- strncpy(hp->name, sl, sizeof hp->name);
- if (slname)
- s_free(slname);
- return 0;
-}
-
-static int
-mkhdr(Hdr *hp, Dir *dir, char *file)
-{
- /*
- * these fields run together, so we format them in order and don't use
- * snprint.
- */
- sprint(hp->mode, "%6lo ", dir->mode & 0777);
- sprint(hp->uid, "%6o ", aruid);
- sprint(hp->gid, "%6o ", argid);
- /*
- * files > 2 bytes can't be described
- * (unless we resort to xustar or exustar formats).
- */
- if (dir->length >= (Off)1<<33) {
- fprint(2, "%s: %s: too large for tar header format\n",
- argv0, file);
- return -1;
- }
- sprint(hp->size, "%11lluo ", dir->length);
- sprint(hp->mtime, "%11luo ", dir->mtime);
- hp->linkflag = (dir->mode&DMDIR? LF_DIR: LF_PLAIN1);
- putfullname(hp, file);
- if (posix) {
- strncpy(hp->magic, "ustar", sizeof hp->magic);
- strncpy(hp->version, "00", sizeof hp->version);
- strncpy(hp->uname, dir->uid, sizeof hp->uname);
- strncpy(hp->gname, dir->gid, sizeof hp->gname);
- }
- sprint(hp->chksum, "%6luo", chksum(hp));
- return 0;
-}
-
-static void addtoar(int ar, char *file, char *shortf);
-
-static void
-addtreetoar(int ar, char *file, char *shortf, int fd)
-{
- int n;
- Dir *dent, *dirents;
- String *name = s_new();
-
- n = dirreadall(fd, &dirents);
- close(fd);
- if (n == 0)
- return;
-
- if (chdir(shortf) < 0)
- sysfatal("chdir %s: %r", file);
- if (DEBUG)
- fprint(2, "chdir %s\t# %s\n", shortf, file);
-
- for (dent = dirents; dent < dirents + n; dent++) {
- s_reset(name);
- s_append(name, file);
- s_append(name, "/");
- s_append(name, dent->name);
- addtoar(ar, s_to_c(name), dent->name);
- }
- s_free(name);
- free(dirents);
-
- if (chdir("..") < 0)
- sysfatal("chdir %s: %r", file);
- if (DEBUG)
- fprint(2, "chdir ..\n");
-}
-
-static void
-addtoar(int ar, char *file, char *shortf)
-{
- int n, fd, isdir, r;
- long bytes;
- ulong blksleft, blksread;
- Hdr *hbp;
- Dir *dir;
-
- fd = open(shortf, OREAD);
- if (fd < 0) {
- fprint(2, "%s: can't open %s: %r\n", argv0, file);
- return;
- }
- dir = dirfstat(fd);
- if (dir == nil)
- sysfatal("can't fstat %s: %r", file);
-
- hbp = getblkz(ar);
- isdir = !!(dir->qid.type&QTDIR);
- r = mkhdr(hbp, dir, file);
- if (r < 0) {
- putbackblk(ar);
- free(dir);
- close(fd);
- return;
- }
- putblk(ar);
-
- blksleft = BYTES2TBLKS(dir->length);
- free(dir);
-
- if (isdir)
- addtreetoar(ar, file, shortf, fd);
- else {
- for (; blksleft > 0; blksleft -= blksread) {
- hbp = getblke(ar);
- blksread = gothowmany(blksleft);
- bytes = blksread * Tblock;
- n = read(fd, hbp, bytes);
- if (n < 0)
- sysfatal("error reading %s: %r", file);
- /*
- * ignore EOF. zero any partial block to aid
- * compression and emergency recovery of data.
- */
- if (n < Tblock)
- memset((char*)hbp + n, 0, bytes - n);
- putblkmany(ar, blksread);
- }
- close(fd);
- if (verbose)
- fprint(2, "%s: a %s\n", argv0, file);
- }
-}
-
-static void
-replace(char **argv)
-{
- int i, ar;
- ulong blksleft, blksread;
- Off bytes;
- Hdr *hp;
-
- if (usefile && creat)
- ar = create(usefile, ORDWR, 0666);
- else if (usefile)
- ar = open(usefile, ORDWR);
- else
- ar = Stdout;
- if (ar < 0)
- sysfatal("can't open archive %s: %r", usefile);
-
- if (usefile && !creat) {
- /* skip quickly to the end */
- while ((hp = readhdr(ar)) != nil) {
- bytes = (isdir(hp)? 0: strtoull(hp->size, nil, 8));
- for (blksleft = BYTES2TBLKS(bytes);
- blksleft > 0 && getblkrd(ar) != nil;
- blksleft -= blksread) {
- blksread = gothowmany(blksleft);
- putreadblks(ar, blksread);
- }
- }
- /*
- * we have just read the end-of-archive Tblock.
- * now seek back over the (big) archive block containing it,
- * and back up curblk ptr over end-of-archive Tblock in memory.
- */
- if (seek(ar, -Tblock*nblock, 1) < 0)
- sysfatal("can't seek back over end-of-archive: %r");
- curblk--;
- }
-
- for (i = 0; argv[i] != nil; i++)
- addtoar(ar, argv[i], argv[i]);
-
- /* write end-of-archive marker */
- getblkz(ar);
- putblk(ar);
- getblkz(ar);
- putlastblk(ar);
-
- if (ar > Stderr)
- close(ar);
-}
-
-/*
- * tar [xt]
- */
-
-/* is pfx a file-name prefix of name? */
-static int
-prefix(char *name, char *pfx)
-{
- int pfxlen = strlen(pfx);
- char clpfx[Maxname+1];
-
- if (pfxlen > Maxname)
- return 0;
- strcpy(clpfx, pfx);
- cleanname(clpfx);
- return strncmp(pfx, name, pfxlen) == 0 &&
- (name[pfxlen] == '\0' || name[pfxlen] == '/');
-}
-
-static int
-match(char *name, char **argv)
-{
- int i;
- char clname[Maxname+1];
-
- if (argv[0] == nil)
- return 1;
- strcpy(clname, name);
- cleanname(clname);
- for (i = 0; argv[i] != nil; i++)
- if (prefix(clname, argv[i]))
- return 1;
- return 0;
-}
-
-static int
-makedir(char *s)
-{
- int f;
-
- if (access(s, AEXIST) == 0)
- return -1;
- f = create(s, OREAD, DMDIR | 0777);
- if (f >= 0)
- close(f);
- return f;
-}
-
-static void
-mkpdirs(char *s)
-{
- int done = 0;
- char *p = s;
-
- while (!done && (p = strchr(p + 1, '/')) != nil) {
- *p = '\0';
- done = (access(s, AEXIST) < 0 && makedir(s) < 0);
- *p = '/';
- }
-}
-
-/* copy a file from the archive into the filesystem */
-static void
-extract1(int ar, Hdr *hp, char *fname)
-{
- int wrbytes, fd = -1, dir = 0, okcreate = 1;
- long mtime = strtol(hp->mtime, nil, 8);
- ulong mode = strtoul(hp->mode, nil, 8) & 0777;
- Off bytes = strtoll(hp->size, nil, 8);
- ulong blksread, blksleft = BYTES2TBLKS(bytes);
- Hdr *hbp;
-
- if (isdir(hp)) {
- mode |= DMDIR|0700;
- blksleft = 0;
- dir = 1;
- }
- switch (hp->linkflag) {
- case LF_LINK:
- case LF_SYMLINK1:
- case LF_SYMLINK2:
- case LF_FIFO:
- blksleft = okcreate = 0;
- break;
- }
- if (relative && fname[0] == '/')
- fname++;
- if (verb == Xtract) {
- cleanname(fname);
- switch (hp->linkflag) {
- case LF_LINK:
- case LF_SYMLINK1:
- case LF_SYMLINK2:
- fprint(2, "%s: can't make (sym)link %s\n",
- argv0, fname);
- break;
- case LF_FIFO:
- fprint(2, "%s: can't make fifo %s\n", argv0, fname);
- break;
- }
- if (okcreate)
- fd = create(fname, (dir? OREAD: OWRITE), mode);
- if (fd < 0) {
- mkpdirs(fname);
- fd = create(fname, (dir? OREAD: OWRITE), mode);
- if (fd < 0 && (!dir || access(fname, AEXIST) < 0))
- fprint(2, "%s: can't create %s: %r\n",
- argv0, fname);
- }
- if (fd >= 0 && verbose)
- fprint(2, "%s: x %s\n", argv0, fname);
- } else if (verbose) {
- char *cp = ctime(mtime);
-
- print("%M %8lld %-12.12s %-4.4s %s\n",
- mode, bytes, cp+4, cp+24, fname);
- } else
- print("%s\n", fname);
-
- for (; blksleft > 0; blksleft -= blksread) {
- hbp = getblkrd(ar);
- if (hbp == nil)
- sysfatal("unexpected EOF on archive extracting %s",
- fname);
- blksread = gothowmany(blksleft);
- wrbytes = (bytes >= Tblock*blksread? Tblock*blksread: bytes);
- if (fd >= 0 && write(fd, (char*)hbp, wrbytes) != wrbytes)
- sysfatal("write error on %s: %r", fname);
- putreadblks(ar, blksread);
- bytes -= wrbytes;
- }
- if (fd >= 0) {
- /*
- * directories should be wstated after we're done
- * creating files in them.
- */
- if (settime) {
- Dir nd;
-
- nulldir(&nd);
- nd.mtime = mtime;
- if (isustar(hp))
- nd.gid = hp->gname;
- dirfwstat(fd, &nd);
- }
- close(fd);
- }
-}
-
-static void
-skip(int ar, Hdr *hp, char *fname)
-{
- Off bytes;
- ulong blksleft, blksread;
- Hdr *hbp;
-
- if (isdir(hp))
- return;
- bytes = strtoull(hp->size, nil, 8);
- blksleft = BYTES2TBLKS(bytes);
- for (; blksleft > 0; blksleft -= blksread) {
- hbp = getblkrd(ar);
- if (hbp == nil)
- sysfatal("unexpected EOF on archive extracting %s",
- fname);
- blksread = gothowmany(blksleft);
- putreadblks(ar, blksread);
- }
-}
-
-static void
-extract(char **argv)
-{
- int ar;
- char *longname;
- Hdr *hp;
-
- if (usefile)
- ar = open(usefile, OREAD);
- else
- ar = Stdin;
- if (ar < 0)
- sysfatal("can't open archive %s: %r", usefile);
- while ((hp = readhdr(ar)) != nil) {
- longname = name(hp);
- if (match(longname, argv))
- extract1(ar, hp, longname);
- else
- skip(ar, hp, longname);
- }
- if (ar > Stderr)
- close(ar);
-}
-
-void
-main(int argc, char *argv[])
-{
- int errflg = 0;
- char *ret = nil;
-
- quotefmtinstall();
- fmtinstall('M', dirmodefmt);
-
- TARGBEGIN {
- case 'c':
- creat++;
- verb = Replace;
- break;
- case 'f':
- usefile = EARGF(usage());
- break;
- case 'g':
- argid = strtoul(EARGF(usage()), 0, 0);
- break;
- case 'p':
- posix++;
- break;
- case 'P':
- posix = 0;
- break;
- case 'r':
- verb = Replace;
- break;
- case 'R':
- relative++;
- break;
- case 't':
- verb = Toc;
- break;
- case 'T':
- settime++;
- break;
- case 'u':
- aruid = strtoul(EARGF(usage()), 0, 0);
- break;
- case 'v':
- verbose++;
- break;
- case 'x':
- verb = Xtract;
- break;
- case '-':
- break;
- default:
- errflg++;
- break;
- } TARGEND
-
- if (argc < 0 || errflg)
- usage();
-
- initblks();
- switch (verb) {
- case Toc:
- case Xtract:
- extract(argv);
- break;
- case Replace:
- if (getwd(origdir, sizeof origdir) == nil)
- strcpy(origdir, "/tmp");
- replace(argv);
- chdir(origdir); /* for profiling */
- break;
- default:
- usage();
- break;
- }
- exits(ret);
-}
