changeset 1379:b02c05e64f20

TAR - this supports archive creation and extraction based on the USTAR format (described in PAX Spec). For (de)compression '-z' gzip is supported.
author Ashwini Sharma <ak.ashwini1981@gmail.com>
date Fri, 04 Jul 2014 21:46:00 -0500
parents 6c54196fce62
children 9748833918b0
files toys/pending/tar.c
diffstat 1 files changed, 808 insertions(+), 0 deletions(-) [+]
line wrap: on
line diff
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/toys/pending/tar.c	Fri Jul 04 21:46:00 2014 -0500
@@ -0,0 +1,808 @@
+/* tar.c - create/extract archives
+ *
+ * Copyright 2014 Ashwini Kumar <ak.ashwini81@gmail.com>
+ *
+ * USTAR interchange format is of interest in
+ * See http://http://pubs.opengroup.org/onlinepubs/9699919799/utilities/pax.html
+ * For writing to external program
+ * http://www.gnu.org/software/tar/manual/html_node/Writing-to-an-External-Program.html
+
+USE_TAR(NEWTOY(tar, "&(no-recursion)(numeric-owner)(no-same-permissions)(overwrite)(exclude)*(to-command):o(no-same-owner)p(same-permissions)k(keep-old)c(create)|h(dereference)x(extract)|t(list)|v(verbose)z(gzip)O(to-stdout)m(touch)X(exclude-from)*T(files-from)*C(directory):f(file):[!txc]", TOYFLAG_USR|TOYFLAG_BIN))
+
+config TAR
+  bool "tar"
+  default n
+  help
+    usage: tar -[cxtzhmvO] [-X FILE] [-T FILE] [-f TARFILE] [-C DIR]
+
+    Create, extract, or list files from a tar file
+
+    Operation:
+    c Create
+    f Name of TARFILE ('-' for stdin/out)
+    h Follow symlinks
+    m Don't restore mtime
+    t List
+    v Verbose
+    x Extract
+    z (De)compress using gzip
+    C Change to DIR before operation
+    O Extract to stdout
+    exclude=FILE File to exclude
+    X File with names to exclude
+    T File with names to include
+*/
+#define FOR_tar
+#include "toys.h"
+
+GLOBALS(
+  char *fname;
+  char *dir;
+  struct arg_list *inc_file;
+  struct arg_list *exc_file;
+  char *tocmd;
+  struct arg_list *exc;
+
+  struct arg_list *inc, *pass;
+  void *inodes, *handle;
+)
+
+struct tar_hdr {
+  char name[100], mode[8], uid[8], gid[8],size[12], mtime[12], chksum[8],
+       type, link[100], magic[8], uname[32], gname[32], major[8], minor[8],
+       prefix[155], padd[12];
+};
+
+struct file_header {
+  char *name, *link_target, *uname, *gname;
+  off_t size;
+  uid_t uid;
+  gid_t gid;
+  mode_t mode;
+  time_t mtime;
+  dev_t device;
+};
+
+struct archive_handler {
+  int src_fd;
+  struct file_header file_hdr;
+  off_t offset;
+  void (*extract_handler)(struct archive_handler*);
+};
+
+struct inode_list {
+  struct inode_list *next;
+  char *arg;
+  ino_t ino;
+  dev_t dev;
+};
+
+static void copy_in_out(int src, int dst, off_t size)
+{
+  int i, rd, rem = size%512, cnt;
+  
+  cnt = size/512 + (rem?1:0);
+
+  for (i = 0; i < cnt; i++) {
+    rd = (((i == cnt-1) && rem)? rem:512);
+    if (readall(src, toybuf, rd) != rd) error_exit("short read");
+    writeall(dst, toybuf, rd);
+  }
+}
+
+//convert to octal
+static void itoo(char *str, int len, off_t val)
+{
+  char *t, tmp[sizeof(off_t)*3+1]; //1 for NUL termination
+  int cnt  = sprintf(tmp, "%0*llo", len, val);
+
+  t = tmp;
+  t += (cnt - len);
+  if (*t == '0') t++;
+  memcpy(str, t, len);
+}
+
+static struct inode_list *seen_inode(void **list, struct stat *st, char *name)
+{
+  if (!st) llist_traverse(*list, llist_free_arg);
+  else if (!S_ISDIR(st->st_mode) && st->st_nlink > 1) {
+    struct inode_list *new;
+
+    for (new = *list; new; new = new->next)
+      if(new->ino == st->st_ino && new->dev == st->st_dev)
+        return new;
+
+    new = xzalloc(sizeof(*new));
+    new->ino = st->st_ino;
+    new->dev = st->st_dev;
+    new->arg = xstrdup(name);
+    new->next = *list;
+    *list = new;
+  }
+  return 0;
+}
+
+static void write_longname(struct archive_handler *tar, char *name, char type)
+{
+  struct tar_hdr tmp;
+  unsigned int sum = 0;
+  int i, sz = strlen(name) +1;
+  char buf[512] = {0,};
+
+  memset(&tmp, 0, sizeof(tmp));
+  strcpy(tmp.name, "././@LongLink");
+  sprintf(tmp.mode, "%0*d", sizeof(tmp.mode)-1, 0);
+  sprintf(tmp.uid, "%0*d", sizeof(tmp.uid)-1, 0);
+  sprintf(tmp.gid, "%0*d", sizeof(tmp.gid)-1, 0);
+  sprintf(tmp.size, "%0*d", sizeof(tmp.size)-1, 0);
+  sprintf(tmp.mtime, "%0*d", sizeof(tmp.mtime)-1, 0);
+  itoo(tmp.size, sizeof(tmp.size), sz);
+  tmp.type = type;
+  memset(tmp.chksum, ' ', 8);
+  strcpy(tmp.magic, "ustar  ");
+  for (i= 0; i < 512; i++) sum += (unsigned int)((char*)&tmp)[i];
+  itoo(tmp.chksum, sizeof(tmp.chksum)-1, sum);
+
+  writeall(tar->src_fd, (void*) &tmp, sizeof(tmp));
+  //write name to archive
+  writeall(tar->src_fd, name, sz);
+  if (sz%512) writeall(tar->src_fd, buf, (512-(sz%512)));
+}
+
+static int filter(struct arg_list *lst, char *name)
+{
+  struct arg_list *cur;
+
+  for (cur = lst; cur; cur = cur->next)
+    if (!fnmatch(cur->arg, name, 1<<3)) return 1;
+  return 0;
+}
+
+static void add_file(struct archive_handler *tar, char **nam, struct stat *st)
+{
+  struct tar_hdr hdr;
+  struct passwd *pw;
+  struct group *gr;
+  struct inode_list *node;
+  int i, fd =-1;
+  char *c, *p, *name = *nam, *lnk, *hname, buf[512] = {0,};
+  unsigned int sum = 0;
+  static int warn = 1;
+
+  for (p = name; *p; p++)
+    if ((p == name || p[-1] == '/') && *p != '/'
+        && filter(TT.exc, p)) return;
+
+  if (S_ISDIR(st->st_mode) && name[strlen(name)-1] != '/') {
+    lnk = xmprintf("%s/",name);
+    free(name);
+    *nam = name = lnk;
+  }
+  hname = name;
+  //remove leading '/' or relative path '../' component
+  if (*hname == '/') hname++;
+  if (!*hname) return;
+  while ((c = strstr(hname, "../"))) hname = c + 3;
+  if (warn && hname != name) {
+    printf("removing leading '%.*s' "
+        "from member names\n",hname-name, name);
+    warn = 0;
+  }
+
+  memset(&hdr, 0, sizeof(hdr));
+  strncpy(hdr.name, hname, sizeof(hdr.name));
+  itoo(hdr.mode, sizeof(hdr.mode), st->st_mode &07777);
+  itoo(hdr.uid, sizeof(hdr.uid), st->st_uid);
+  itoo(hdr.gid, sizeof(hdr.gid), st->st_gid);
+  itoo(hdr.size, sizeof(hdr.size), 0); //set size later
+  itoo(hdr.mtime, sizeof(hdr.mtime), st->st_mtime);
+  for (i=0; i<sizeof(hdr.chksum); i++) hdr.chksum[i] = ' ';
+
+  if ((node = seen_inode(&TT.inodes, st, hname))) {
+    //this is a hard link
+    hdr.type = '1';
+    if (strlen(node->arg) > sizeof(hdr.link))
+      write_longname(tar, hname, 'K'); //write longname LINK
+    strncpy(hdr.link, node->arg, sizeof(hdr.link));
+  } else if (S_ISREG(st->st_mode)) {
+    hdr.type = '0';
+    if (st->st_size <= (off_t)0777777777777LL)
+      itoo(hdr.size, sizeof(hdr.size), st->st_size);
+    else {
+      error_msg("can't store file '%s' of size '%d'\n", hname, st->st_size);
+      return;
+    }
+  } else if (S_ISLNK(st->st_mode)) {
+    hdr.type = '2'; //'K' long link
+    if (!(lnk = xreadlink(name))) {
+      perror_msg("readlink");
+      return;
+    }
+    if (strlen(lnk) > sizeof(hdr.link))
+      write_longname(tar, hname, 'K'); //write longname LINK
+    strncpy(hdr.link, lnk, sizeof(hdr.link));
+    free(lnk);
+  }
+  else if (S_ISDIR(st->st_mode)) hdr.type = '5';
+  else if (S_ISFIFO(st->st_mode)) hdr.type = '6';
+  else if (S_ISBLK(st->st_mode) || S_ISCHR(st->st_mode)) {
+    hdr.type = (S_ISCHR(st->st_mode))?'3':'4';
+    itoo(hdr.major, sizeof(hdr.major), major(st->st_rdev));
+    itoo(hdr.minor, sizeof(hdr.minor), minor(st->st_rdev));
+  } else {
+    error_msg("unknown file type '%s'");
+    return;
+  }
+  if (strlen(hname) > sizeof(hdr.name))
+          write_longname(tar, hname, 'L'); //write longname NAME
+  strcpy(hdr.magic, "ustar  ");
+  if ((pw = getpwuid(st->st_uid)))
+    snprintf(hdr.uname, sizeof(hdr.uname), "%s", pw->pw_name);
+  else snprintf(hdr.uname, sizeof(hdr.uname), "%d", st->st_uid);
+
+  if ((gr = getgrgid(st->st_gid)))
+    snprintf(hdr.gname, sizeof(hdr.gname), "%s", gr->gr_name);
+  else snprintf(hdr.gname, sizeof(hdr.gname), "%d", st->st_gid);
+
+  //calculate chksum.
+  for (i= 0; i < 512; i++) sum += (unsigned int)((char*)&hdr)[i];
+  itoo(hdr.chksum, sizeof(hdr.chksum)-1, sum);
+  if (toys.optflags & FLAG_v) printf("%s\n",hname);
+  writeall(tar->src_fd, (void*)&hdr, 512);
+
+  //write actual data to archive
+  if (hdr.type != '0') return; //nothing to write
+  if ((fd = open(name, O_RDONLY)) < 0) {
+    perror_msg("can't open '%s'", name);
+    return;
+  }
+  copy_in_out(fd, tar->src_fd, st->st_size);
+  if (st->st_size%512) writeall(tar->src_fd, buf, (512-(st->st_size%512)));
+  close(fd);
+}
+
+static int add_to_tar(struct dirtree *node)
+{
+  struct stat st;
+  char *path;
+  struct archive_handler *hdl = (struct archive_handler*)TT.handle;
+
+  if (!fstat(hdl->src_fd, &st) && st.st_dev == node->st.st_dev
+      && st.st_ino == node->st.st_ino) {
+    error_msg("'%s' file is the archive; not dumped", TT.fname);
+    return ((DIRTREE_RECURSE | ((toys.optflags & FLAG_h)?DIRTREE_SYMFOLLOW:0)));
+  }
+
+  if (node->parent && !dirtree_notdotdot(node)) return 0;
+  path = dirtree_path(node, 0);
+  add_file(hdl, &path, &(node->st)); //path may be modified
+  free(path);
+  if (toys.optflags & FLAG_no_recursion) return 0;
+  return ((DIRTREE_RECURSE | ((toys.optflags & FLAG_h)?DIRTREE_SYMFOLLOW:0)));
+}
+
+static void compress_stream(struct archive_handler *tar_hdl)
+{
+  int pipefd[2];
+  pid_t cpid;
+
+  if (pipe(pipefd) == -1) error_exit("pipe");
+
+  signal(SIGPIPE, SIG_IGN);
+  cpid = fork();
+  if (cpid == -1) perror_exit("fork");
+
+  if (!cpid) {    /* Child reads from pipe */
+    char *argv[] = {"gzip", "-f", NULL};
+    xclose(pipefd[1]); /* Close unused write*/
+    dup2(pipefd[0], 0);
+    dup2(tar_hdl->src_fd, 1); //write to tar fd
+    xexec(argv);
+  } else {
+    xclose(pipefd[0]);          /* Close unused read end */
+    dup2(pipefd[1], tar_hdl->src_fd); //write to pipe
+  }
+}
+
+static void extract_to_stdout(struct archive_handler *tar)
+{
+  struct file_header *file_hdr = &tar->file_hdr;
+
+  copy_in_out(tar->src_fd, 0, file_hdr->size);
+  tar->offset += file_hdr->size;
+}
+
+static void extract_to_command(struct archive_handler *tar)
+{
+  int pipefd[2], status = 0;
+  pid_t cpid;
+  struct file_header *file_hdr = &tar->file_hdr;
+
+  if (pipe(pipefd) == -1) error_exit("pipe");
+  if (!S_ISREG(file_hdr->mode)) return; //only regular files are supported.
+
+  cpid = fork();
+  if (cpid == -1) perror_exit("fork");
+
+  if (!cpid) {    // Child reads from pipe
+    char buf[64], *argv[4] = {"sh", "-c", TT.tocmd, NULL};
+
+    setenv("TAR_FILETYPE", "f", 1);
+    sprintf(buf, "%0o", file_hdr->mode);
+    setenv("TAR_MODE", buf, 1);
+    sprintf(buf, "%ld", (long)file_hdr->size);
+    setenv("TAR_SIZE", buf, 1);
+    setenv("TAR_FILENAME", file_hdr->name, 1);
+    setenv("TAR_UNAME", file_hdr->uname, 1);
+    setenv("TAR_GNAME", file_hdr->gname, 1);
+    sprintf(buf, "%0o", (int)file_hdr->mtime);
+    setenv("TAR_MTIME", buf, 1);
+    sprintf(buf, "%0o", file_hdr->uid);
+    setenv("TAR_UID", buf, 1);
+    sprintf(buf, "%0o", file_hdr->gid);
+    setenv("TAR_GID", buf, 1);
+
+    xclose(pipefd[1]); // Close unused write
+    dup2(pipefd[0], 0);
+    signal(SIGPIPE, SIG_DFL);
+    xexec(argv);
+  } else {
+    xclose(pipefd[0]);  // Close unused read end
+    copy_in_out(tar->src_fd, pipefd[1], file_hdr->size);
+    tar->offset += file_hdr->size;
+    xclose(pipefd[1]);
+    waitpid(cpid, &status, 0);
+    if (WIFSIGNALED(status))
+      xprintf("tar : %d: child returned %d\n", cpid, WTERMSIG(status));
+  }
+}
+
+static void extract_to_disk(struct archive_handler *tar)
+{
+  int flags, dst_fd = -1;
+  char *s;
+  struct stat ex;
+  struct file_header *file_hdr = &tar->file_hdr;
+
+  if (file_hdr->name[strlen(file_hdr->name)-1] == '/')
+    file_hdr->name[strlen(file_hdr->name)-1] = 0;
+  //Regular file with preceding path
+  if ((s = strrchr(file_hdr->name, '/'))) {
+    if (mkpathat(AT_FDCWD, file_hdr->name, 00, 2) && errno !=EEXIST) {
+      error_msg(":%s: not created", file_hdr->name);
+      return;
+    }
+  }
+
+  //remove old file, if exists
+  if (!(toys.optflags & FLAG_k) && !S_ISDIR(file_hdr->mode)
+      && !lstat( file_hdr->name, &ex)) {
+    if (unlink(file_hdr->name)) {
+      perror_msg("can't remove: %s",file_hdr->name);
+    }
+  }
+
+  //hard link
+  if (S_ISREG(file_hdr->mode) && file_hdr->link_target) {
+    if (link(file_hdr->link_target, file_hdr->name))
+      perror_msg("can't link '%s' -> '%s'",file_hdr->name, file_hdr->link_target);
+    goto COPY;
+  }
+
+  switch (file_hdr->mode & S_IFMT) {
+    case S_IFREG:
+      flags = O_WRONLY|O_CREAT|O_EXCL;
+      if (toys.optflags & FLAG_overwrite) flags = O_WRONLY|O_CREAT|O_TRUNC;
+      dst_fd = open(file_hdr->name, flags, file_hdr->mode & 07777);
+      if (dst_fd == -1) perror_msg("%s: can't open", file_hdr->name);
+      break;
+    case S_IFDIR:
+      if ((mkdir(file_hdr->name, file_hdr->mode) == -1) && errno != EEXIST)
+        perror_msg("%s: can't create", file_hdr->name);
+      break;
+    case S_IFLNK:
+      if (symlink(file_hdr->link_target, file_hdr->name))
+        perror_msg("can't link '%s' -> '%s'",file_hdr->name, file_hdr->link_target);
+      break;
+    case S_IFBLK:
+    case S_IFCHR:
+    case S_IFIFO:
+      if (mknod(file_hdr->name, file_hdr->mode, file_hdr->device))
+        perror_msg("can't create '%s'", file_hdr->name);
+      break;
+    default:
+      printf("type not yet supported\n");
+      break;
+  }
+
+  //copy file....
+COPY:
+  copy_in_out(tar->src_fd, dst_fd, file_hdr->size);
+  tar->offset += file_hdr->size;
+  close(dst_fd);
+
+  if (S_ISLNK(file_hdr->mode)) return;
+  if (!(toys.optflags & FLAG_o)) {
+    //set ownership..., --no-same-owner, --numeric-owner
+    uid_t u = file_hdr->uid;
+    gid_t g = file_hdr->gid;
+
+    if (!(toys.optflags & FLAG_numeric_owner)) {
+      struct group *gr = getgrnam(file_hdr->gname);
+      struct passwd *pw = getpwnam(file_hdr->uname);
+      if (pw) u = pw->pw_uid;
+      if (gr) g = gr->gr_gid;
+    }
+    chown(file_hdr->name, u, g);
+  }
+
+  if (toys.optflags & FLAG_p) // || !(toys.optflags & FLAG_no_same_permissions))
+    chmod(file_hdr->name, file_hdr->mode);
+
+  //apply mtime
+  if (!(toys.optflags & FLAG_m)) {
+    struct timeval times[2] = {{file_hdr->mtime, 0},{file_hdr->mtime, 0}};
+    utimes(file_hdr->name, times);
+  }
+}
+
+static void add_to_list(struct arg_list **llist, char *name)
+{
+  struct arg_list **list = llist;
+
+  while (*list) list=&((*list)->next);
+  *list = xzalloc(sizeof(struct arg_list));
+  (*list)->arg = name;
+  if ((name[strlen(name)-1] == '/') && strlen(name) != 1)
+    name[strlen(name)-1] = '\0';
+}
+
+static void add_from_file(struct arg_list **llist, struct arg_list *flist)
+{
+  char *line = NULL;
+
+  while (flist) {
+    int fd = 0;
+
+    if (strcmp((char *)flist->arg, "-"))
+      fd = xopen((char *)flist->arg, O_RDONLY);
+
+    while ((line = get_line(fd))) {
+      add_to_list(llist, line);
+    }
+    if (fd) close(fd);
+    flist = flist->next;
+  }
+}
+
+static struct archive_handler *init_handler()
+{
+  struct archive_handler *tar_hdl = xzalloc(sizeof(struct archive_handler));
+  tar_hdl->extract_handler = extract_to_disk;
+  return tar_hdl;
+}
+
+//convert octal to int
+static int otoi(char *str, int len)
+{
+  long val;
+  char *endp, inp[len+1]; //1 for NUL termination
+
+  memcpy(inp, str, len);
+  inp[len] = '\0'; //nul-termination made sure
+  val = strtol(inp, &endp, 8);
+  if (*endp && *endp != ' ') error_exit("invalid param");
+  return (int)val;
+}
+
+static void extract_stream(struct archive_handler *tar_hdl)
+{
+  int pipefd[2];              
+  pid_t cpid;                 
+
+  if (pipe(pipefd) == -1) error_exit("pipe");
+
+  cpid = fork();
+  if (cpid == -1) perror_exit("fork");
+
+  if (!cpid) {    /* Child reads from pipe */
+    char *argv[] = {"gunzip", "-cf", "-", NULL};
+    xclose(pipefd[0]); /* Close unused read*/
+    dup2(tar_hdl->src_fd, 0);
+    dup2(pipefd[1], 1); //write to pipe
+    xexec(argv);
+  } else {
+    xclose(pipefd[1]);          /* Close unused read end */
+    dup2(pipefd[0], tar_hdl->src_fd); //read from pipe
+  }
+}
+
+static char *process_extended_hdr(struct archive_handler *tar, int size)
+{
+  char *value = NULL, *p, *buf = xzalloc(size+1);
+
+  if (readall(tar->src_fd, buf, size) != size) error_exit("short read");
+  buf[size] = 0;
+  tar->offset += size;
+  p = buf;
+
+  while (size) {
+    char *key;
+    int len, n;
+
+    // extended records are of the format: "LEN NAME=VALUE\n"
+    sscanf(p, "%d %n", &len, &n);
+    key = p + n;
+    p += len;
+    size -= len;
+    p[-1] = 0;
+    if (size < 0) {
+      error_msg("corrupted extended header");
+      break;
+    }
+
+    len = strlen("path=");
+    if (!strncmp(key, "path=", len)) {
+      value = key + strlen("path=");
+      break;
+    }
+  }
+  return ((value)?xstrdup(value) : NULL);
+}
+
+static void tar_skip(struct archive_handler *tar, int sz)
+{
+  int x;
+
+  while ((x = lskip(tar->src_fd, sz))) {
+    tar->offset += sz - x;
+    sz = x;
+  }
+  tar->offset += sz;
+}
+
+static void unpack_tar(struct archive_handler *tar_hdl)
+{
+  struct tar_hdr tar;
+  struct file_header *file_hdr;
+  int i, j, maj, min, sz, e = 0;
+  unsigned int cksum;
+  unsigned char *gzMagic;
+  char *longname = NULL, *longlink = NULL;
+
+  while (1) {
+    cksum = 0;
+    if (tar_hdl->offset % 512) {
+      sz = 512 - tar_hdl->offset % 512;
+      tar_skip(tar_hdl, sz);
+    }
+    i = readall(tar_hdl->src_fd, &tar, 512);
+    tar_hdl->offset += i;
+    if (i != 512) {
+      if (i >= 2) goto CHECK_MAGIC; //may be a small (<512 byte)zipped file
+      error_exit("read error");
+    }
+
+    if (!tar.name[0]) {
+      if (e) return; //end of tar 2 empty blocks
+      e = 1;//empty jump to next block
+      continue;
+    }
+    if (strncmp(tar.magic, "ustar", 5)) {
+      //try detecting by reading magic
+CHECK_MAGIC:
+      gzMagic = (unsigned char*)&tar;
+      if ((gzMagic[0] == 0x1f) && (gzMagic[1] == 0x8b) 
+          && !lseek(tar_hdl->src_fd, -i, SEEK_CUR)) {
+        tar_hdl->offset -= i;
+        extract_stream(tar_hdl);
+        continue;
+      }
+      error_exit("invalid tar format");
+    }
+
+    for (j = 0; j<148; j++) cksum += (unsigned int)((char*)&tar)[j];
+    for (j = 156; j<500; j++) cksum += (unsigned int)((char*)&tar)[j];
+    //cksum field itself treated as ' '
+    for ( j= 0; j<8; j++) cksum += (unsigned int)' ';
+
+    if (cksum != otoi(tar.chksum, sizeof(tar.chksum))) error_exit("wrong cksum");
+
+    file_hdr = &tar_hdl->file_hdr;
+    memset(file_hdr, 0, sizeof(struct file_header));
+    file_hdr->mode = otoi(tar.mode, sizeof(tar.mode));
+    file_hdr->uid = otoi(tar.uid, sizeof(tar.uid));
+    file_hdr->gid = otoi(tar.gid, sizeof(tar.gid));
+    file_hdr->size = otoi(tar.size, sizeof(tar.size));
+    file_hdr->mtime = otoi(tar.mtime, sizeof(tar.mtime));
+    file_hdr->uname = xstrdup(tar.uname);
+    file_hdr->gname = xstrdup(tar.gname);
+    maj = otoi(tar.major, sizeof(tar.major));
+    min = otoi(tar.minor, sizeof(tar.minor));
+    file_hdr->device = makedev(maj, min);
+
+    if (tar.type <= '7') {
+      if (tar.link[0]) {
+        sz = sizeof(tar.link);
+        file_hdr->link_target = xmalloc(sz + 1);
+        memcpy(file_hdr->link_target, tar.link, sz);
+        file_hdr->link_target[sz] = '\0';
+      }
+
+      file_hdr->name = xzalloc(256);// pathname supported size
+      if (tar.prefix[0]) {
+        memcpy(file_hdr->name, tar.prefix, sizeof(tar.prefix));
+        sz = strlen(file_hdr->name);
+        if (file_hdr->name[sz-1] != '/') file_hdr->name[sz] = '/';
+      }
+      sz = strlen(file_hdr->name);
+      memcpy(file_hdr->name + sz, tar.name, sizeof(tar.name));
+      if (file_hdr->name[255]) error_exit("filename too long");
+    }
+
+    switch (tar.type) {
+      //    case '\0':
+      case '0':
+      case '7':
+      case '1': //Hard Link
+        file_hdr->mode |= S_IFREG;
+        break;
+      case '2':
+        file_hdr->mode |= S_IFLNK;
+        break;
+      case '3':
+        file_hdr->mode |= S_IFCHR;
+        break;
+      case '4':
+        file_hdr->mode |= S_IFBLK;
+        break;
+      case '5':
+        file_hdr->mode |= S_IFDIR;
+        break;
+      case '6':
+        file_hdr->mode |= S_IFIFO;
+        break;
+      case 'K':
+        longlink = xzalloc(file_hdr->size +1);
+        xread(tar_hdl->src_fd, longlink, file_hdr->size);
+        tar_hdl->offset += file_hdr->size;
+        continue;
+      case 'L':
+        free(longname);
+        longname = xzalloc(file_hdr->size +1);           
+        xread(tar_hdl->src_fd, longname, file_hdr->size);
+        tar_hdl->offset += file_hdr->size;
+        continue;
+      case 'D':
+      case 'M':
+      case 'N':
+      case 'S':
+      case 'V':
+      case 'g':  // pax global header
+        tar_skip(tar_hdl, file_hdr->size);
+        continue;
+      case 'x':  // pax extended header
+        free(longname);
+        longname = process_extended_hdr(tar_hdl, file_hdr->size);
+        continue;
+      default: break;
+    }
+
+    if (longname) {
+      free(file_hdr->name);
+      file_hdr->name = longname;
+      longname = NULL;
+    }
+    if (longlink) {
+      free(file_hdr->link_target);
+      file_hdr->link_target = longlink;
+      longlink = NULL;
+    }
+
+    if ((file_hdr->mode & S_IFREG) && 
+        file_hdr->name[strlen(file_hdr->name)-1] == '/') {
+      file_hdr->name[strlen(file_hdr->name)-1] = '\0';
+      file_hdr->mode &= ~S_IFREG;
+      file_hdr->mode |= S_IFDIR;
+    }
+
+    if ((file_hdr->link_target && *(file_hdr->link_target)) 
+        || S_ISLNK(file_hdr->mode) || S_ISDIR(file_hdr->mode))
+      file_hdr->size = 0;
+
+    if (filter(TT.exc, file_hdr->name) ||
+        (TT.inc && !filter(TT.inc, file_hdr->name))) goto SKIP;
+    add_to_list(&TT.pass, xstrdup(file_hdr->name));
+
+    if (toys.optflags & FLAG_t) {
+      if (toys.optflags & FLAG_v) {
+        char perm[11];
+        struct tm *lc = localtime((const time_t*)&(file_hdr->mtime));
+
+        mode_to_string(file_hdr->mode, perm);
+        printf("%s %s/%s %9ld %d-%02d-%02d %02d:%02d:%02d ",perm,file_hdr->uname,
+            file_hdr->gname, (long)file_hdr->size, 1900+lc->tm_year,
+            1+lc->tm_mon, lc->tm_mday, lc->tm_hour, lc->tm_min, lc->tm_sec);
+      }
+      printf("%s",file_hdr->name);
+      if (file_hdr->link_target) printf(" -> %s",file_hdr->link_target);
+      xputc('\n');
+SKIP:
+      tar_skip(tar_hdl, file_hdr->size);
+    } else {
+      if (toys.optflags & FLAG_v) printf("%s\n",file_hdr->name);
+      tar_hdl->extract_handler(tar_hdl);
+    }
+    free(file_hdr->name);
+    free(file_hdr->link_target);
+    free(file_hdr->uname);
+    free(file_hdr->gname);
+  }
+}
+
+void tar_main(void)
+{
+  struct archive_handler *tar_hdl;
+  int fd = 0, flags = O_RDONLY;
+  struct arg_list *tmp;
+  char **args = toys.optargs;
+
+  if (!toys.argv[1]) {
+    toys.exithelp++;
+    error_exit(NULL);
+  }
+
+  if (!geteuid()) toys.optflags |= FLAG_p;
+
+  for (tmp = TT.exc; tmp; tmp = tmp->next)
+    tmp->arg = xstrdup(tmp->arg); //freeing at the end fails otherwise
+
+  while(*args) add_to_list(&TT.inc, xstrdup(*args++));
+  if (toys.optflags & FLAG_X) add_from_file(&TT.exc, TT.exc_file);
+  if (toys.optflags & FLAG_T) add_from_file(&TT.inc, TT.inc_file);
+
+  if (toys.optflags & FLAG_c) {
+    if (!TT.inc) error_exit("empty archive");
+    fd = 1, flags = O_WRONLY|O_CREAT|O_TRUNC;
+  }
+  if ((toys.optflags & FLAG_f) && strcmp(TT.fname, "-")) 
+    fd = xcreate(TT.fname, flags, 0666);
+  if (toys.optflags & FLAG_C) xchdir(TT.dir);
+
+  tar_hdl = init_handler();
+  tar_hdl->src_fd = fd;
+
+  if (toys.optflags & FLAG_x || toys.optflags & FLAG_t) {
+    if (toys.optflags & FLAG_O) tar_hdl->extract_handler = extract_to_stdout;
+    if (toys.optflags & FLAG_to_command) {
+      signal(SIGPIPE, SIG_IGN); //will be using pipe between child & parent
+      tar_hdl->extract_handler = extract_to_command;
+    }
+    if (toys.optflags & FLAG_z) extract_stream(tar_hdl);
+    unpack_tar(tar_hdl);
+    for (tmp = TT.inc; tmp; tmp = tmp->next)
+      if (!filter(TT.exc, tmp->arg) && !filter(TT.pass, tmp->arg))
+        error_msg("'%s' not in archive", tmp->arg);
+  } else if (toys.optflags & FLAG_c) {
+    //create the tar here.
+    if (toys.optflags & FLAG_z) compress_stream(tar_hdl);
+    for (tmp = TT.inc; tmp; tmp = tmp->next) {
+      TT.handle = tar_hdl;
+      //recurse thru dir and add files to archive
+      struct dirtree *root = dirtree_add_node(0,tmp->arg,toys.optflags & FLAG_h);
+
+      if (root) dirtree_handle_callback(root, add_to_tar);
+    }
+    memset(toybuf, 0, 1024);
+    writeall(tar_hdl->src_fd, toybuf, 1024);
+    seen_inode(&TT.inodes, 0, 0);
+  }
+
+  if (CFG_TOYBOX_FREE) {
+    close(tar_hdl->src_fd);
+    free(tar_hdl);
+    llist_traverse(TT.exc, llist_free_arg);
+    llist_traverse(TT.inc, llist_free_arg);
+    llist_traverse(TT.pass, llist_free_arg);
+  }
+}