stty: fix option parsing bug (spotted by Sascha Hauer <s.hauer@pengutronix.de>)
[oweals/busybox.git] / archival / tar.c
index 8074c2d1a909ed1453a2c67151b32669b01a9e37..79979b05f437f84316f6db50e1b7830da14b34f0 100644 (file)
@@ -1,15 +1,15 @@
 /* vi: set sw=4 ts=4: */
 /*
- * Mini tar implementation for busybox 
+ * Mini tar implementation for busybox
  *
- * Modifed to use common extraction code used by ar, cpio, dpkg-deb, dpkg
- *  Glenn McGrath <bug1@optushome.com.au>
+ * Modified to use common extraction code used by ar, cpio, dpkg-deb, dpkg
+ *  Glenn McGrath <bug1@iinet.net.au>
  *
  * Note, that as of BusyBox-0.43, tar has been completely rewritten from the
- * ground up.  It still has remnents of the old code lying about, but it is
+ * ground up.  It still has remnants of the old code lying about, but it is
  * very different now (i.e., cleaner, less global variables, etc.)
  *
- * Copyright (C) 1999-2003 by Erik Andersen <andersen@codepoet.org>
+ * Copyright (C) 1999-2004 by Erik Andersen <andersen@codepoet.org>
  *
  * Based in part in the tar implementation in sash
  *  Copyright (c) 1999 by David I. Bell
  *
  * Based in part on the tar implementation from busybox-0.28
  *  Copyright (C) 1995 Bruce Perens
- *  This is free software under the GNU General Public License.
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- * General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  *
+ * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
  */
 
-#include <fcntl.h>
-#include <getopt.h>
-#include <search.h>
-#include <stdio.h>
-#include <stdlib.h>
-#include <unistd.h>
 #include <fnmatch.h>
-#include <string.h>
-#include <errno.h>
-#include <signal.h>
-#include <sys/wait.h>
-#include <sys/socket.h>
-#include "unarchive.h"
+#include <getopt.h>
 #include "busybox.h"
+#include "unarchive.h"
 
-#ifdef CONFIG_FEATURE_TAR_CREATE
+#if ENABLE_FEATURE_TAR_CREATE
 
 /* Tar file constants  */
-# define TAR_MAGIC          "ustar"    /* ustar and a null */
-# define TAR_VERSION        "  "       /* Be compatable with GNU tar format */
-
-# ifndef MAJOR
-#  define MAJOR(dev) (((dev)>>8)&0xff)
-#  define MINOR(dev) ((dev)&0xff)
-# endif
 
-static const int TAR_BLOCK_SIZE = 512;
-static const int TAR_MAGIC_LEN = 6;
-static const int TAR_VERSION_LEN = 2;
+#define TAR_BLOCK_SIZE         512
 
 /* POSIX tar Header Block, from POSIX 1003.1-1990  */
-enum { NAME_SIZE = 100 };      /* because gcc won't let me use 'static const int' */
-struct TarHeader {             /* byte offset */
-       char name[NAME_SIZE];   /*   0-99 */
-       char mode[8];           /* 100-107 */
-       char uid[8];            /* 108-115 */
-       char gid[8];            /* 116-123 */
-       char size[12];          /* 124-135 */
-       char mtime[12];         /* 136-147 */
-       char chksum[8];         /* 148-155 */
-       char typeflag;          /* 156-156 */
-       char linkname[NAME_SIZE];       /* 157-256 */
-       char magic[6];          /* 257-262 */
-       char version[2];        /* 263-264 */
-       char uname[32];         /* 265-296 */
-       char gname[32];         /* 297-328 */
-       char devmajor[8];       /* 329-336 */
-       char devminor[8];       /* 337-344 */
-       char prefix[155];       /* 345-499 */
-       char padding[12];       /* 500-512 (pad to exactly the TAR_BLOCK_SIZE) */
-};
+#define NAME_SIZE      100
+#define NAME_SIZE_STR "100"
 typedef struct TarHeader TarHeader;
+struct TarHeader {               /* byte offset */
+       char name[NAME_SIZE];     /*   0-99 */
+       char mode[8];             /* 100-107 */
+       char uid[8];              /* 108-115 */
+       char gid[8];              /* 116-123 */
+       char size[12];            /* 124-135 */
+       char mtime[12];           /* 136-147 */
+       char chksum[8];           /* 148-155 */
+       char typeflag;            /* 156-156 */
+       char linkname[NAME_SIZE]; /* 157-256 */
+       char magic[6];            /* 257-262 */
+       char version[2];          /* 263-264 */
+       char uname[32];           /* 265-296 */
+       char gname[32];           /* 297-328 */
+       char devmajor[8];         /* 329-336 */
+       char devminor[8];         /* 337-344 */
+       char prefix[155];         /* 345-499 */
+       char padding[12];         /* 500-512 (pad to exactly the TAR_BLOCK_SIZE) */
+};
 
 /*
-** writeTarFile(),  writeFileToTarball(), and writeTarHeader() are
+** writeTarFile(), writeFileToTarball(), and writeTarHeader() are
 ** the only functions that deal with the HardLinkInfo structure.
 ** Even these functions use the xxxHardLinkInfo() functions.
 */
@@ -105,20 +73,19 @@ struct HardLinkInfo {
 };
 
 /* Some info to be carried along when creating a new tarball */
+typedef struct TarBallInfo TarBallInfo;
 struct TarBallInfo {
-       char *fileName;         /* File name of the tarball */
-       int tarFd;                      /* Open-for-write file descriptor
-                                                  for the tarball */
+       int tarFd;                              /* Open-for-write file descriptor
+                                                          for the tarball */
        struct stat statBuf;    /* Stat info for the tarball, letting
                                                           us know the inode and device that the
-                                                          tarball lives, so we can avoid trying 
+                                                          tarball lives, so we can avoid trying
                                                           to include the tarball into itself */
-       int verboseFlag;        /* Whether to print extra stuff or not */
+       int verboseFlag;                /* Whether to print extra stuff or not */
        const llist_t *excludeList;     /* List of files to not include */
        HardLinkInfo *hlInfoHead;       /* Hard Link Tracking Information */
        HardLinkInfo *hlInfo;   /* Hard Link Info for the current file */
 };
-typedef struct TarBallInfo TarBallInfo;
 
 /* A nice enum with all the possible tar file content types */
 enum TarFileType {
@@ -137,26 +104,26 @@ enum TarFileType {
 typedef enum TarFileType TarFileType;
 
 /* Might be faster (and bigger) if the dev/ino were stored in numeric order;) */
-static inline void addHardLinkInfo(HardLinkInfo ** hlInfoHeadPtr,
+static void addHardLinkInfo(HardLinkInfo ** hlInfoHeadPtr,
                                        struct stat *statbuf,
-                                       const char *name)
+                                       const char *fileName)
 {
        /* Note: hlInfoHeadPtr can never be NULL! */
        HardLinkInfo *hlInfo;
 
-       hlInfo = (HardLinkInfo *) xmalloc(sizeof(HardLinkInfo) + strlen(name));
+       hlInfo = xmalloc(sizeof(HardLinkInfo) + strlen(fileName));
        hlInfo->next = *hlInfoHeadPtr;
        *hlInfoHeadPtr = hlInfo;
        hlInfo->dev = statbuf->st_dev;
        hlInfo->ino = statbuf->st_ino;
        hlInfo->linkCount = statbuf->st_nlink;
-       strcpy(hlInfo->name, name);
+       strcpy(hlInfo->name, fileName);
 }
 
 static void freeHardLinkInfo(HardLinkInfo ** hlInfoHeadPtr)
 {
-       HardLinkInfo *hlInfo = NULL;
-       HardLinkInfo *hlInfoNext = NULL;
+       HardLinkInfo *hlInfo;
+       HardLinkInfo *hlInfoNext;
 
        if (hlInfoHeadPtr) {
                hlInfo = *hlInfoHeadPtr;
@@ -167,158 +134,224 @@ static void freeHardLinkInfo(HardLinkInfo ** hlInfoHeadPtr)
                }
                *hlInfoHeadPtr = NULL;
        }
-       return;
 }
 
 /* Might be faster (and bigger) if the dev/ino were stored in numeric order;) */
-static inline HardLinkInfo *findHardLinkInfo(HardLinkInfo * hlInfo, struct stat *statbuf)
+static HardLinkInfo *findHardLinkInfo(HardLinkInfo * hlInfo, struct stat *statbuf)
 {
        while (hlInfo) {
                if ((statbuf->st_ino == hlInfo->ino) && (statbuf->st_dev == hlInfo->dev))
                        break;
                hlInfo = hlInfo->next;
        }
-       return (hlInfo);
+       return hlInfo;
 }
 
 /* Put an octal string into the specified buffer.
- * The number is zero and space padded and possibly null padded.
- * Returns TRUE if successful.  */
-static int putOctal(char *cp, int len, long value)
+ * The number is zero padded and possibly null terminated.
+ * Stores low-order bits only if whole value does not fit. */
+static void putOctal(char *cp, int len, off_t value)
 {
-       int tempLength;
-       char tempBuffer[32];
+       char tempBuffer[sizeof(off_t)*3+1];
        char *tempString = tempBuffer;
+       int width;
 
-       /* Create a string of the specified length with an initial space,
-        * leading zeroes and the octal number, and a trailing null.  */
-       sprintf(tempString, "%0*lo", len - 1, value);
+       width = sprintf(tempBuffer, "%0*"OFF_FMT"o", len, value);
+       tempString += (width - len);
 
-       /* If the string is too large, suppress the leading space.  */
-       tempLength = strlen(tempString) + 1;
-       if (tempLength > len) {
-               tempLength--;
+       /* If string has leading zeroes, we can drop one */
+       /* and field will have trailing '\0' */
+       /* (increases chances of compat with other tars) */
+       if (tempString[0] == '0')
                tempString++;
-       }
 
-       /* If the string is still too large, suppress the trailing null.  */
-       if (tempLength > len)
-               tempLength--;
+       /* Copy the string to the field */
+       memcpy(cp, tempString, len);
+}
+#define PUT_OCTAL(a, b) putOctal((a), sizeof(a), (b))
 
-       /* If the string is still too large, fail.  */
-       if (tempLength > len)
-               return FALSE;
+static void chksum_and_xwrite(int fd, struct TarHeader* hp)
+{
+       /* POSIX says that checksum is done on unsigned bytes
+        * (Sun and HP-UX gets it wrong... more details in
+        * GNU tar source) */
+       const unsigned char *cp;
+       int chksum, size;
 
-       /* Copy the string to the field.  */
-       memcpy(cp, tempString, len);
+       strcpy(hp->magic, "ustar  ");
 
-       return TRUE;
+       /* Calculate and store the checksum (i.e., the sum of all of the bytes of
+        * the header).  The checksum field must be filled with blanks for the
+        * calculation.  The checksum field is formatted differently from the
+        * other fields: it has 6 digits, a null, then a space -- rather than
+        * digits, followed by a null like the other fields... */
+       memset(hp->chksum, ' ', sizeof(hp->chksum));
+       cp = (const unsigned char *) hp;
+       chksum = 0;
+       size = sizeof(*hp);
+       do { chksum += *cp++; } while (--size);
+       putOctal(hp->chksum, sizeof(hp->chksum)-1, chksum);
+
+       /* Now write the header out to disk */
+       xwrite(fd, hp, sizeof(*hp));
 }
 
+#if ENABLE_FEATURE_TAR_GNU_EXTENSIONS
+static void writeLongname(int fd, int type, const char *name, int dir)
+{
+       static const struct {
+               char mode[8];             /* 100-107 */
+               char uid[8];              /* 108-115 */
+               char gid[8];              /* 116-123 */
+               char size[12];            /* 124-135 */
+               char mtime[12];           /* 136-147 */
+       } prefilled = {
+               "0000000",
+               "0000000",
+               "0000000",
+               "00000000000",
+               "00000000000",
+       };
+       struct TarHeader header;
+       int size;
+
+       dir = !!dir; /* normalize: 0/1 */
+       size = strlen(name) + 1 + dir; /* GNU tar uses strlen+1 */
+       /* + dir: account for possible '/' */
+
+       memset(&header, 0, sizeof(header));
+       strcpy(header.name, "././@LongLink");
+       memcpy(header.mode, prefilled.mode, sizeof(prefilled));
+       PUT_OCTAL(header.size, size);
+       header.typeflag = type;
+       chksum_and_xwrite(fd, &header);
+
+       /* Write filename[/] and pad the block. */
+       /* dir=0: writes 'name<NUL>', pads */
+       /* dir=1: writes 'name', writes '/<NUL>', pads */
+       dir *= 2;
+       xwrite(fd, name, size - dir);
+       xwrite(fd, "/", dir);
+       size = (-size) & (TAR_BLOCK_SIZE-1);
+       memset(&header, 0, size);
+       xwrite(fd, &header, size);
+}
+#endif
+
 /* Write out a tar header for the specified file/directory/whatever */
-static inline int writeTarHeader(struct TarBallInfo *tbInfo,
-                                                                const char *header_name,
-                                                                const char *real_name, struct stat *statbuf)
+void BUG_tar_header_size(void);
+static int writeTarHeader(struct TarBallInfo *tbInfo,
+               const char *header_name, const char *fileName, struct stat *statbuf)
 {
-       long chksum = 0;
        struct TarHeader header;
-       const unsigned char *cp = (const unsigned char *) &header;
-       ssize_t size = sizeof(struct TarHeader);
 
-       memset(&header, 0, size);
+       if (sizeof(header) != 512)
+               BUG_tar_header_size();
+
+       memset(&header, 0, sizeof(struct TarHeader));
 
        strncpy(header.name, header_name, sizeof(header.name));
 
-       putOctal(header.mode, sizeof(header.mode), statbuf->st_mode);
-       putOctal(header.uid, sizeof(header.uid), statbuf->st_uid);
-       putOctal(header.gid, sizeof(header.gid), statbuf->st_gid);
-       putOctal(header.size, sizeof(header.size), 0);  /* Regular file size is handled later */
-       putOctal(header.mtime, sizeof(header.mtime), statbuf->st_mtime);
-       strncpy(header.magic, TAR_MAGIC TAR_VERSION,
-                       TAR_MAGIC_LEN + TAR_VERSION_LEN);
+       /* POSIX says to mask mode with 07777. */
+       PUT_OCTAL(header.mode, statbuf->st_mode & 07777);
+       PUT_OCTAL(header.uid, statbuf->st_uid);
+       PUT_OCTAL(header.gid, statbuf->st_gid);
+       memset(header.size, '0', sizeof(header.size)-1); /* Regular file size is handled later */
+       PUT_OCTAL(header.mtime, statbuf->st_mtime);
 
-       /* Enter the user and group names (default to root if it fails) */
-       if (my_getpwuid(header.uname, statbuf->st_uid) == NULL)
-               strcpy(header.uname, "root");
-       if (my_getgrgid(header.gname, statbuf->st_gid) == NULL)
-               strcpy(header.gname, "root");
+       /* Enter the user and group names */
+       safe_strncpy(header.uname, get_cached_username(statbuf->st_uid), sizeof(header.uname));
+       safe_strncpy(header.gname, get_cached_groupname(statbuf->st_gid), sizeof(header.gname));
 
        if (tbInfo->hlInfo) {
                /* This is a hard link */
                header.typeflag = LNKTYPE;
                strncpy(header.linkname, tbInfo->hlInfo->name,
                                sizeof(header.linkname));
+#if ENABLE_FEATURE_TAR_GNU_EXTENSIONS
+               /* Write out long linkname if needed */
+               if (header.linkname[sizeof(header.linkname)-1])
+                       writeLongname(tbInfo->tarFd, GNULONGLINK,
+                                       tbInfo->hlInfo->name, 0);
+#endif
        } else if (S_ISLNK(statbuf->st_mode)) {
-               char *lpath = xreadlink(real_name);
-
-               if (!lpath)             /* Already printed err msg inside xreadlink() */
-                       return (FALSE);
+               char *lpath = xmalloc_readlink_or_warn(fileName);
+               if (!lpath)
+                       return FALSE;
                header.typeflag = SYMTYPE;
                strncpy(header.linkname, lpath, sizeof(header.linkname));
+#if ENABLE_FEATURE_TAR_GNU_EXTENSIONS
+               /* Write out long linkname if needed */
+               if (header.linkname[sizeof(header.linkname)-1])
+                       writeLongname(tbInfo->tarFd, GNULONGLINK, lpath, 0);
+#else
+               /* If it is larger than 100 bytes, bail out */
+               if (header.linkname[sizeof(header.linkname)-1]) {
+                       free(lpath);
+                       bb_error_msg("names longer than "NAME_SIZE_STR" chars not supported");
+                       return FALSE;
+               }
+#endif
                free(lpath);
        } else if (S_ISDIR(statbuf->st_mode)) {
                header.typeflag = DIRTYPE;
-               strncat(header.name, "/", sizeof(header.name));
+               /* Append '/' only if there is a space for it */
+               if (!header.name[sizeof(header.name)-1])
+                       header.name[strlen(header.name)] = '/';
        } else if (S_ISCHR(statbuf->st_mode)) {
                header.typeflag = CHRTYPE;
-               putOctal(header.devmajor, sizeof(header.devmajor),
-                                MAJOR(statbuf->st_rdev));
-               putOctal(header.devminor, sizeof(header.devminor),
-                                MINOR(statbuf->st_rdev));
+               PUT_OCTAL(header.devmajor, major(statbuf->st_rdev));
+               PUT_OCTAL(header.devminor, minor(statbuf->st_rdev));
        } else if (S_ISBLK(statbuf->st_mode)) {
                header.typeflag = BLKTYPE;
-               putOctal(header.devmajor, sizeof(header.devmajor),
-                                MAJOR(statbuf->st_rdev));
-               putOctal(header.devminor, sizeof(header.devminor),
-                                MINOR(statbuf->st_rdev));
+               PUT_OCTAL(header.devmajor, major(statbuf->st_rdev));
+               PUT_OCTAL(header.devminor, minor(statbuf->st_rdev));
        } else if (S_ISFIFO(statbuf->st_mode)) {
                header.typeflag = FIFOTYPE;
        } else if (S_ISREG(statbuf->st_mode)) {
+               if (sizeof(statbuf->st_size) > 4
+                && statbuf->st_size > (off_t)0777777777777LL
+               ) {
+                       bb_error_msg_and_die("cannot store file '%s' "
+                               "of size %"OFF_FMT"d, aborting",
+                               fileName, statbuf->st_size);
+               }
                header.typeflag = REGTYPE;
-               putOctal(header.size, sizeof(header.size), statbuf->st_size);
+               PUT_OCTAL(header.size, statbuf->st_size);
        } else {
-               bb_error_msg("%s: Unknown file type", real_name);
-               return (FALSE);
+               bb_error_msg("%s: unknown file type", fileName);
+               return FALSE;
        }
 
-       /* Calculate and store the checksum (i.e., the sum of all of the bytes of
-        * the header).  The checksum field must be filled with blanks for the
-        * calculation.  The checksum field is formatted differently from the
-        * other fields: it has [6] digits, a null, then a space -- rather than
-        * digits, followed by a null like the other fields... */
-       memset(header.chksum, ' ', sizeof(header.chksum));
-       cp = (const unsigned char *) &header;
-       while (size-- > 0)
-               chksum += *cp++;
-       putOctal(header.chksum, 7, chksum);
+#if ENABLE_FEATURE_TAR_GNU_EXTENSIONS
+       /* Write out long name if needed */
+       /* (we, like GNU tar, output long linkname *before* long name) */
+       if (header.name[sizeof(header.name)-1])
+               writeLongname(tbInfo->tarFd, GNULONGNAME,
+                               header_name, S_ISDIR(statbuf->st_mode));
+#endif
 
        /* Now write the header out to disk */
-       if ((size =
-                bb_full_write(tbInfo->tarFd, (char *) &header,
-                                       sizeof(struct TarHeader))) < 0) {
-               bb_error_msg(bb_msg_io_error, real_name);
-               return (FALSE);
-       }
-       /* Pad the header up to the tar block size */
-       for (; size < TAR_BLOCK_SIZE; size++) {
-               write(tbInfo->tarFd, "\0", 1);
-       }
-       /* Now do the verbose thing (or not) */
+       chksum_and_xwrite(tbInfo->tarFd, &header);
 
+       /* Now do the verbose thing (or not) */
        if (tbInfo->verboseFlag) {
                FILE *vbFd = stdout;
 
-               if (tbInfo->tarFd == fileno(stdout))    /* If the archive goes to stdout, verbose to stderr */
+               if (tbInfo->tarFd == STDOUT_FILENO)     /* If the archive goes to stdout, verbose to stderr */
                        vbFd = stderr;
-
-               fprintf(vbFd, "%s\n", header.name);
+               /* GNU "tar cvvf" prints "extended" listing a-la "ls -l" */
+               /* We don't have such excesses here: for us "v" == "vv" */
+               /* '/' is probably a GNUism */
+               fprintf(vbFd, "%s%s\n", header_name,
+                               S_ISDIR(statbuf->st_mode) ? "/" : "");
        }
 
-       return (TRUE);
+       return TRUE;
 }
 
-# ifdef CONFIG_FEATURE_TAR_FROM
-static inline int exclude_file(const llist_t *excluded_files, const char *file)
+#if ENABLE_FEATURE_TAR_FROM
+static int exclude_file(const llist_t *excluded_files, const char *file)
 {
        while (excluded_files) {
                if (excluded_files->data[0] == '/') {
@@ -340,20 +373,23 @@ static inline int exclude_file(const llist_t *excluded_files, const char *file)
 
        return 0;
 }
-# endif
+#else
+#define exclude_file(excluded_files, file) 0
+#endif
 
 static int writeFileToTarball(const char *fileName, struct stat *statbuf,
-                                                         void *userData)
+                       void *userData, int depth ATTRIBUTE_UNUSED)
 {
        struct TarBallInfo *tbInfo = (struct TarBallInfo *) userData;
        const char *header_name;
+       int inputFileFd = -1;
 
        /*
-          ** Check to see if we are dealing with a hard link.
-          ** If so -
-          ** Treat the first occurance of a given dev/inode as a file while
-          ** treating any additional occurances as hard links.  This is done
-          ** by adding the file information to the HardLinkInfo linked list.
+        * Check to see if we are dealing with a hard link.
+        * If so -
+        * Treat the first occurance of a given dev/inode as a file while
+        * treating any additional occurances as hard links.  This is done
+        * by adding the file information to the HardLinkInfo linked list.
         */
        tbInfo->hlInfo = NULL;
        if (statbuf->st_nlink > 1) {
@@ -365,7 +401,7 @@ static int writeFileToTarball(const char *fileName, struct stat *statbuf,
        /* It is against the rules to archive a socket */
        if (S_ISSOCK(statbuf->st_mode)) {
                bb_error_msg("%s: socket ignored", fileName);
-               return (TRUE);
+               return TRUE;
        }
 
        /* It is a bad idea to store the archive we are in the process of creating,
@@ -374,7 +410,7 @@ static int writeFileToTarball(const char *fileName, struct stat *statbuf,
        if (tbInfo->statBuf.st_dev == statbuf->st_dev &&
                tbInfo->statBuf.st_ino == statbuf->st_ino) {
                bb_error_msg("%s: file is the archive; skipping", fileName);
-               return (TRUE);
+               return TRUE;
        }
 
        header_name = fileName;
@@ -382,67 +418,76 @@ static int writeFileToTarball(const char *fileName, struct stat *statbuf,
                static int alreadyWarned = FALSE;
 
                if (alreadyWarned == FALSE) {
-                       bb_error_msg("Removing leading '/' from member names");
+                       bb_error_msg("removing leading '/' from member names");
                        alreadyWarned = TRUE;
                }
                header_name++;
        }
 
+#if !ENABLE_FEATURE_TAR_GNU_EXTENSIONS
        if (strlen(fileName) >= NAME_SIZE) {
-               bb_error_msg(bb_msg_name_longer_than_foo, NAME_SIZE);
-               return (TRUE);
+               bb_error_msg("names longer than "NAME_SIZE_STR" chars not supported");
+               return TRUE;
        }
+#endif
 
        if (header_name[0] == '\0')
                return TRUE;
 
-# ifdef CONFIG_FEATURE_TAR_FROM
-       if (exclude_file(tbInfo->excludeList, header_name)) {
+       if (exclude_file(tbInfo->excludeList, header_name))
                return SKIP;
+
+       /* Is this a regular file? */
+       if (tbInfo->hlInfo == NULL && S_ISREG(statbuf->st_mode)) {
+               /* open the file we want to archive, and make sure all is well */
+               inputFileFd = open_or_warn(fileName, O_RDONLY);
+               if (inputFileFd < 0) {
+                       return FALSE;
+               }
        }
-# endif                                                        /* CONFIG_FEATURE_TAR_FROM */
 
+       /* Add an entry to the tarball */
        if (writeTarHeader(tbInfo, header_name, fileName, statbuf) == FALSE) {
-               return (FALSE);
+               return FALSE;
        }
 
-       /* Now, if the file is a regular file, copy it out to the tarball */
-       if ((tbInfo->hlInfo == NULL)
-               && (S_ISREG(statbuf->st_mode))) {
-               int inputFileFd;
-               ssize_t readSize = 0;
-
-               /* open the file we want to archive, and make sure all is well */
-               if ((inputFileFd = open(fileName, O_RDONLY)) < 0) {
-                       bb_perror_msg("%s: Cannot open", fileName);
-                       return (FALSE);
-               }
+       /* If it was a regular file, write out the body */
+       if (inputFileFd >= 0) {
+               size_t readSize;
+               /* Write the file to the archive. */
+               /* We record size into header first, */
+               /* and then write out file. If file shrinks in between, */
+               /* tar will be corrupted. So we don't allow for that. */
+               /* NB: GNU tar 1.16 warns and pads with zeroes */
+               /* or even seeks back and updates header */
+               bb_copyfd_exact_size(inputFileFd, tbInfo->tarFd, statbuf->st_size);
+               ////off_t readSize;
+               ////readSize = bb_copyfd_size(inputFileFd, tbInfo->tarFd, statbuf->st_size);
+               ////if (readSize != statbuf->st_size && readSize >= 0) {
+               ////    bb_error_msg_and_die("short read from %s, aborting", fileName);
+               ////}
+
+               /* Check that file did not grow in between? */
+               /* if (safe_read(inputFileFd, 1) == 1) warn but continue? */
 
-               /* write the file to the archive */
-               readSize = bb_copyfd_eof(inputFileFd, tbInfo->tarFd);
+               close(inputFileFd);
 
                /* Pad the file up to the tar block size */
-               for (; (readSize % TAR_BLOCK_SIZE) != 0; readSize++) {
-                       write(tbInfo->tarFd, "\0", 1);
-               }
-               close(inputFileFd);
+               /* (a few tricks here in the name of code size) */
+               readSize = (-(int)statbuf->st_size) & (TAR_BLOCK_SIZE-1);
+               memset(bb_common_bufsiz1, 0, readSize);
+               xwrite(tbInfo->tarFd, bb_common_bufsiz1, readSize);
        }
 
-       return (TRUE);
+       return TRUE;
 }
 
-static inline int writeTarFile(const int tar_fd, const int verboseFlag,
-                                                          const llist_t *include, const llist_t *exclude, const int gzip)
+static int writeTarFile(const int tar_fd, const int verboseFlag,
+       const unsigned long dereferenceFlag, const llist_t *include,
+       const llist_t *exclude, const int gzip)
 {
-#ifdef CONFIG_FEATURE_TAR_GZIP
-       int gzipDataPipe[2] = { -1, -1 };
-       int gzipStatusPipe[2] = { -1, -1 };
        pid_t gzipPid = 0;
-       volatile int vfork_exec_errno = 0;
-#endif
-
        int errorFlag = FALSE;
-       ssize_t size;
        struct TarBallInfo tbInfo;
 
        tbInfo.hlInfoHead = NULL;
@@ -454,35 +499,38 @@ static inline int writeTarFile(const int tar_fd, const int verboseFlag,
        /* Store the stat info for the tarball's file, so
         * can avoid including the tarball into itself....  */
        if (fstat(tbInfo.tarFd, &tbInfo.statBuf) < 0)
-               bb_perror_msg_and_die("Couldnt stat tar file");
+               bb_perror_msg_and_die("cannot stat tar file");
 
-#ifdef CONFIG_FEATURE_TAR_GZIP
-       if (gzip) {
-               if (pipe(gzipDataPipe) < 0 || pipe(gzipStatusPipe) < 0) {
-                       bb_perror_msg_and_die("Failed to create gzip pipe");
-               }
+       if ((ENABLE_FEATURE_TAR_GZIP || ENABLE_FEATURE_TAR_BZIP2) && gzip) {
+               int gzipDataPipe[2] = { -1, -1 };
+               int gzipStatusPipe[2] = { -1, -1 };
+               volatile int vfork_exec_errno = 0;
+               const char *zip_exec = (gzip == 1) ? "gzip" : "bzip2";
 
-               signal(SIGPIPE, SIG_IGN);       /* we only want EPIPE on errors */
+               if (pipe(gzipDataPipe) < 0 || pipe(gzipStatusPipe) < 0)
+                       bb_perror_msg_and_die("pipe");
+
+               signal(SIGPIPE, SIG_IGN); /* we only want EPIPE on errors */
+
+#if defined(__GNUC__) && __GNUC__
+               /* Avoid vfork clobbering */
+               (void) &include;
+               (void) &errorFlag;
+               (void) &zip_exec;
+#endif
 
-# if __GNUC__
-                       /* Avoid vfork clobbering */
-                       (void) &include;
-                       (void) &errorFlag;
-# endif
                gzipPid = vfork();
 
                if (gzipPid == 0) {
                        dup2(gzipDataPipe[0], 0);
                        close(gzipDataPipe[1]);
 
-                       if (tbInfo.tarFd != 1);
                        dup2(tbInfo.tarFd, 1);
 
                        close(gzipStatusPipe[0]);
-                       fcntl(gzipStatusPipe[1], F_SETFD, FD_CLOEXEC);  /* close on exec shows sucess */
+                       fcntl(gzipStatusPipe[1], F_SETFD, FD_CLOEXEC);  /* close on exec shows success */
 
-                       execl("/bin/gzip", "gzip", "-f", 0);
+                       BB_EXECLP(zip_exec, zip_exec, "-f", NULL);
                        vfork_exec_errno = errno;
 
                        close(gzipStatusPipe[1]);
@@ -494,11 +542,11 @@ static inline int writeTarFile(const int tar_fd, const int verboseFlag,
                        while (1) {
                                char buf;
 
-                               int n = bb_full_read(gzipStatusPipe[0], &buf, 1);
+                               int n = full_read(gzipStatusPipe[0], &buf, 1);
 
                                if (n == 0 && vfork_exec_errno != 0) {
                                        errno = vfork_exec_errno;
-                                       bb_perror_msg_and_die("Could not exec gzip process");
+                                       bb_perror_msg_and_die("cannot exec %s", zip_exec);
                                } else if ((n < 0) && (errno == EAGAIN || errno == EINTR))
                                        continue;       /* try it again */
                                break;
@@ -506,52 +554,57 @@ static inline int writeTarFile(const int tar_fd, const int verboseFlag,
                        close(gzipStatusPipe[0]);
 
                        tbInfo.tarFd = gzipDataPipe[1];
-               } else {
-                       bb_perror_msg_and_die("Failed to vfork gzip process");
-               }
+               } else bb_perror_msg_and_die("vfork gzip");
        }
-#endif
 
        tbInfo.excludeList = exclude;
 
        /* Read the directory/files and iterate over them one at a time */
        while (include) {
-               if (!recursive_action(include->data, TRUE, FALSE, FALSE,
-                                                         writeFileToTarball, writeFileToTarball,
-                                                         (void *) &tbInfo)) {
+               if (!recursive_action(include->data, ACTION_RECURSE |
+                               (dereferenceFlag ? ACTION_FOLLOWLINKS : 0),
+                               writeFileToTarball, writeFileToTarball, &tbInfo, 0))
+               {
                        errorFlag = TRUE;
                }
                include = include->link;
        }
        /* Write two empty blocks to the end of the archive */
-       for (size = 0; size < (2 * TAR_BLOCK_SIZE); size++) {
-               write(tbInfo.tarFd, "\0", 1);
-       }
+       memset(bb_common_bufsiz1, 0, 2*TAR_BLOCK_SIZE);
+       xwrite(tbInfo.tarFd, bb_common_bufsiz1, 2*TAR_BLOCK_SIZE);
 
        /* To be pedantically correct, we would check if the tarball
         * is smaller than 20 tar blocks, and pad it if it was smaller,
         * but that isn't necessary for GNU tar interoperability, and
         * so is considered a waste of space */
 
-       /* Hang up the tools, close up shop, head home */
+       /* Close so the child process (if any) will exit */
        close(tbInfo.tarFd);
-       if (errorFlag)
-               bb_error_msg("Error exit delayed from previous errors");
 
-       freeHardLinkInfo(&tbInfo.hlInfoHead);
+       /* Hang up the tools, close up shop, head home */
+       if (ENABLE_FEATURE_CLEAN_UP)
+               freeHardLinkInfo(&tbInfo.hlInfoHead);
 
-#ifdef CONFIG_FEATURE_TAR_GZIP
-       if (gzip && gzipPid) {
-               if (waitpid(gzipPid, NULL, 0) == -1)
-                       printf("Couldnt wait ?");
+       if (errorFlag)
+               bb_error_msg("error exit delayed from previous errors");
+
+       if (gzipPid) {
+               int status;
+               if (waitpid(gzipPid, &status, 0) == -1)
+                       bb_perror_msg("waitpid");
+               else if (!WIFEXITED(status) || WEXITSTATUS(status))
+                       /* gzip was killed or has exited with nonzero! */
+                       errorFlag = TRUE;
        }
-#endif
-
-       return !errorFlag;
+       return errorFlag;
 }
-#endif                                                 /* tar_create */
+#else
+int writeTarFile(const int tar_fd, const int verboseFlag,
+       const unsigned long dereferenceFlag, const llist_t *include,
+       const llist_t *exclude, const int gzip);
+#endif /* FEATURE_TAR_CREATE */
 
-#ifdef CONFIG_FEATURE_TAR_FROM
+#if ENABLE_FEATURE_TAR_FROM
 static llist_t *append_file_list_to_list(llist_t *list)
 {
        FILE *src_stream;
@@ -560,330 +613,326 @@ static llist_t *append_file_list_to_list(llist_t *list)
        char *line;
        llist_t *newlist = NULL;
 
-       while(cur) {
-               src_stream = bb_xfopen(cur->data, "r");
+       while (cur) {
+               src_stream = xfopen(cur->data, "r");
                tmp = cur;
                cur = cur->link;
                free(tmp);
-       while((line = bb_get_chomped_line_from_file(src_stream)) != NULL) {
-                       newlist = llist_add_to(newlist, line);
-       }
-       fclose(src_stream);
+               while ((line = xmalloc_getline(src_stream)) != NULL) {
+                       /* kill trailing '/' unless the string is just "/" */
+                       char *cp = last_char_is(line, '/');
+                       if (cp > line)
+                               *cp = '\0';
+                       llist_add_to(&newlist, line);
+               }
+               fclose(src_stream);
        }
        return newlist;
 }
+#else
+#define append_file_list_to_list(x) 0
 #endif
 
-#ifdef CONFIG_FEATURE_TAR_COMPRESS
+#if ENABLE_FEATURE_TAR_COMPRESS
 static char get_header_tar_Z(archive_handle_t *archive_handle)
 {
-       /* Cant lseek over pipe's */
-       archive_handle->seek = seek_by_char;
+       /* Can't lseek over pipes */
+       archive_handle->seek = seek_by_read;
 
        /* do the decompression, and cleanup */
-       if ((bb_xread_char(archive_handle->src_fd) != 0x1f) || (bb_xread_char(archive_handle->src_fd) != 0x9d)) {
-               bb_error_msg_and_die("Invalid magic");
+       if (xread_char(archive_handle->src_fd) != 0x1f
+        || xread_char(archive_handle->src_fd) != 0x9d
+       ) {
+               bb_error_msg_and_die("invalid magic");
        }
 
        archive_handle->src_fd = open_transformer(archive_handle->src_fd, uncompress);
        archive_handle->offset = 0;
-       while (get_header_tar(archive_handle) == EXIT_SUCCESS);
+       while (get_header_tar(archive_handle) == EXIT_SUCCESS)
+               /* nothing */;
 
        /* Can only do one file at a time */
-       return(EXIT_FAILURE);
+       return EXIT_FAILURE;
 }
-#endif
-
-#define CTX_TEST       (1 << 0)
-#define CTX_EXTRACT    (1 << 1)
-#define TAR_OPT_BASEDIR  (1 << 2)
-#define TAR_OPT_TARNAME  (1 << 3)
-#define TAR_OPT_2STDOUT  (1 << 4)
-#define TAR_OPT_P        (1 << 5)
-#define TAR_OPT_VERBOSE  (1 << 6)
-#define TAR_OPT_KEEP_OLD       (1 << 7)
-
-#ifdef CONFIG_FEATURE_TAR_CREATE
-# define CTX_CREATE    (1 << 8)
-# define TAR_OPT_STR_CREATE    "c"
-# define TAR_OPT_FLAG_CREATE   1
-#else
-//# define CTX_CREATE  0
-# define TAR_OPT_STR_CREATE    ""
-# define TAR_OPT_FLAG_CREATE   0
-#endif
-
-#ifdef CONFIG_FEATURE_TAR_BZIP2
-# define TAR_OPT_BZIP2 (1 << (8 + TAR_OPT_FLAG_CREATE)) 
-# define TAR_OPT_STR_BZIP2     "j"
-# define TAR_OPT_FLAG_BZIP2    1
-#else
-# define TAR_OPT_STR_BZIP2     ""
-# define TAR_OPT_FLAG_BZIP2    0
-#endif
-
-#ifdef CONFIG_FEATURE_TAR_FROM
-# define TAR_OPT_FROM_FILE     (1 << (8 + TAR_OPT_FLAG_CREATE + TAR_OPT_FLAG_BZIP2))
-# define TAR_OPT_EXCLUDE_FROM  (1 << (8 + TAR_OPT_FLAG_CREATE + TAR_OPT_FLAG_BZIP2 + 1))
-# define TAR_OPT_STR_FROM      "T:X:"
-# define TAR_OPT_FLAG_FROM     2
 #else
-# define TAR_OPT_STR_FROM      ""
-# define TAR_OPT_FLAG_FROM     0
+#define get_header_tar_Z NULL
 #endif
 
-#ifdef CONFIG_FEATURE_TAR_GZIP
-# define TAR_OPT_GZIP  (1 << (8 + TAR_OPT_FLAG_CREATE + TAR_OPT_FLAG_BZIP2 + TAR_OPT_FLAG_FROM))
-# define TAR_OPT_STR_GZIP      "z"
-# define TAR_OPT_FLAG_GZIP     1
-#else
-# define TAR_OPT_STR_GZIP      ""
-# define TAR_OPT_FLAG_GZIP     0
-#endif
+#ifdef CHECK_FOR_CHILD_EXITCODE
+/* Looks like it isn't needed - tar detects malformed (truncated)
+ * archive if e.g. bunzip2 fails */
+static int child_error;
 
-#ifdef CONFIG_FEATURE_TAR_COMPRESS
-# define TAR_OPT_UNCOMPRESS    (1 << (8 + TAR_OPT_FLAG_CREATE + TAR_OPT_FLAG_BZIP2 + TAR_OPT_FLAG_FROM + TAR_OPT_FLAG_GZIP))
-# define TAR_OPT_STR_COMPRESS  "Z"
-#else 
-# define TAR_OPT_STR_COMPRESS  ""
+static void handle_SIGCHLD(int status)
+{
+       /* Actually, 'status' is a signo. We reuse it for other needs */
+
+       /* Wait for any child without blocking */
+       if (waitpid(-1, &status, WNOHANG) < 0)
+               /* wait failed?! I'm confused... */
+               return;
+
+       if (WIFEXITED(status) && WEXITSTATUS(status)==0)
+               /* child exited with 0 */
+               return;
+       /* Cannot happen?
+       if (!WIFSIGNALED(status) && !WIFEXITED(status)) return; */
+       child_error = 1;
+}
 #endif
 
-static const char tar_options[]="txC:f:Opvk" \
-       TAR_OPT_STR_CREATE \
-       TAR_OPT_STR_BZIP2 \
-       TAR_OPT_STR_FROM \
-       TAR_OPT_STR_GZIP \
-       TAR_OPT_STR_COMPRESS;
-
-#ifdef CONFIG_FEATURE_TAR_LONG_OPTIONS
+enum {
+       OPTBIT_KEEP_OLD = 7,
+       USE_FEATURE_TAR_CREATE(  OPTBIT_CREATE      ,)
+       USE_FEATURE_TAR_CREATE(  OPTBIT_DEREFERENCE ,)
+       USE_FEATURE_TAR_BZIP2(   OPTBIT_BZIP2       ,)
+       USE_FEATURE_TAR_LZMA(    OPTBIT_LZMA        ,)
+       USE_FEATURE_TAR_FROM(    OPTBIT_INCLUDE_FROM,)
+       USE_FEATURE_TAR_FROM(    OPTBIT_EXCLUDE_FROM,)
+       USE_FEATURE_TAR_GZIP(    OPTBIT_GZIP        ,)
+       USE_FEATURE_TAR_COMPRESS(OPTBIT_COMPRESS    ,)
+       OPTBIT_NOPRESERVE_OWN,
+       OPTBIT_NOPRESERVE_PERM,
+       OPT_TEST         = 1 << 0, // t
+       OPT_EXTRACT      = 1 << 1, // x
+       OPT_BASEDIR      = 1 << 2, // C
+       OPT_TARNAME      = 1 << 3, // f
+       OPT_2STDOUT      = 1 << 4, // O
+       OPT_P            = 1 << 5, // p
+       OPT_VERBOSE      = 1 << 6, // v
+       OPT_KEEP_OLD     = 1 << 7, // k
+       OPT_CREATE       = USE_FEATURE_TAR_CREATE(  (1<<OPTBIT_CREATE      )) + 0, // c
+       OPT_DEREFERENCE  = USE_FEATURE_TAR_CREATE(  (1<<OPTBIT_DEREFERENCE )) + 0, // h
+       OPT_BZIP2        = USE_FEATURE_TAR_BZIP2(   (1<<OPTBIT_BZIP2       )) + 0, // j
+       OPT_LZMA         = USE_FEATURE_TAR_LZMA(    (1<<OPTBIT_LZMA        )) + 0, // a
+       OPT_INCLUDE_FROM = USE_FEATURE_TAR_FROM(    (1<<OPTBIT_INCLUDE_FROM)) + 0, // T
+       OPT_EXCLUDE_FROM = USE_FEATURE_TAR_FROM(    (1<<OPTBIT_EXCLUDE_FROM)) + 0, // X
+       OPT_GZIP         = USE_FEATURE_TAR_GZIP(    (1<<OPTBIT_GZIP        )) + 0, // z
+       OPT_COMPRESS     = USE_FEATURE_TAR_COMPRESS((1<<OPTBIT_COMPRESS    )) + 0, // Z
+       OPT_NOPRESERVE_OWN  = 1 << OPTBIT_NOPRESERVE_OWN , // no-same-owner
+       OPT_NOPRESERVE_PERM = 1 << OPTBIT_NOPRESERVE_PERM, // no-same-permissions
+};
+#if ENABLE_FEATURE_TAR_LONG_OPTIONS
 static const struct option tar_long_options[] = {
-       { "list",                       0,      NULL,   't' },
-       { "extract",            0,      NULL,   'x' },
-       { "directory",          1,      NULL,   'C' },
-       { "file",                       1,      NULL,   'f'     },
-       { "to-stdout",          0,      NULL,   'O' },
-       { "same-permissions",   0,      NULL,   'p' },
-       { "verbose",            0,      NULL,   'v' },
-       { "keep-old",           0,      NULL,   'k' },
-# ifdef CONFIG_FEATURE_TAR_CREATE
-       { "create",                     0,      NULL,   'c' },
+       { "list",               0,  NULL,   't' },
+       { "extract",            0,  NULL,   'x' },
+       { "directory",          1,  NULL,   'C' },
+       { "file",               1,  NULL,   'f' },
+       { "to-stdout",          0,  NULL,   'O' },
+       { "same-permissions",   0,  NULL,   'p' },
+       { "verbose",            0,  NULL,   'v' },
+       { "keep-old",           0,  NULL,   'k' },
+# if ENABLE_FEATURE_TAR_CREATE
+       { "create",             0,  NULL,   'c' },
+       { "dereference",        0,  NULL,   'h' },
 # endif
-# ifdef CONFIG_FEATURE_TAR_BZIP2
-       { "bzip2",                      0,      NULL,   'j' },
+# if ENABLE_FEATURE_TAR_BZIP2
+       { "bzip2",              0,  NULL,   'j' },
 # endif
-# ifdef CONFIG_FEATURE_TAR_FROM
-       { "from-file",          1,      NULL,   'T' },
-       { "exclude-from",       1,      NULL,   'X' },
+# if ENABLE_FEATURE_TAR_LZMA
+       { "lzma",               0,  NULL,   'a' },
 # endif
-# ifdef CONFIG_FEATURE_TAR_GZIP
-       { "gzip",                       0,      NULL,   'z' },
+# if ENABLE_FEATURE_TAR_FROM
+       { "files-from",         1,  NULL,   'T' },
+       { "exclude-from",       1,  NULL,   'X' },
 # endif
-# ifdef CONFIG_FEATURE_TAR_COMPRESS
-       { "compress",           0,      NULL,   'Z' },
+# if ENABLE_FEATURE_TAR_GZIP
+       { "gzip",               0,  NULL,   'z' },
 # endif
-       { 0,                 0, 0, 0 }
+# if ENABLE_FEATURE_TAR_COMPRESS
+       { "compress",           0,  NULL,   'Z' },
+# endif
+       { "no-same-owner",      0,  NULL,   0xfd },
+       { "no-same-permissions",0,  NULL,   0xfe },
+       /* --exclude takes next bit position in option mask, */
+       /* therefore we have to either put it _after_ --no-same-perm */
+       /* or add OPT[BIT]_EXCLUDE before OPT[BIT]_NOPRESERVE_OWN */
+# if ENABLE_FEATURE_TAR_FROM
+       { "exclude",            1,  NULL,   0xff },
+# endif
+       { 0,                    0, 0, 0 }
 };
 #endif
 
+int tar_main(int argc, char **argv);
 int tar_main(int argc, char **argv)
 {
        char (*get_header_ptr)(archive_handle_t *) = get_header_tar;
        archive_handle_t *tar_handle;
        char *base_dir = NULL;
        const char *tar_filename = "-";
-       unsigned long opt;
-       unsigned long ctx_flag = 0;
-
-       if (argc < 2) {
-               bb_show_usage();
-       }
-
-       /* Prepend '-' to the first argument if required */
-       if (argv[1][0] != '-') {
-               char *tmp;
-
-               bb_xasprintf(&tmp, "-%s", argv[1]);
-               argv[1] = tmp;
-       }
+       unsigned opt;
+       int verboseFlag = 0;
+#if ENABLE_FEATURE_TAR_LONG_OPTIONS && ENABLE_FEATURE_TAR_FROM
+       llist_t *excludes = NULL;
+#endif
 
        /* Initialise default values */
        tar_handle = init_handle();
-       tar_handle->flags = ARCHIVE_CREATE_LEADING_DIRS | ARCHIVE_PRESERVE_DATE | ARCHIVE_EXTRACT_UNCONDITIONAL;
+       tar_handle->flags = ARCHIVE_CREATE_LEADING_DIRS
+                         | ARCHIVE_PRESERVE_DATE
+                         | ARCHIVE_EXTRACT_UNCONDITIONAL;
 
-       bb_opt_complementaly = "c~tx:t~cx:x~ct:X*:T*";
-#ifdef CONFIG_FEATURE_TAR_LONG_OPTIONS
-       bb_applet_long_options = tar_long_options;
+       /* Prepend '-' to the first argument if required */
+       opt_complementary = "--:" // first arg is options
+               "tt:vv:" // count -t,-v
+               "?:" // bail out with usage instead of error return
+               "X::T::" // cumulative lists
+#if ENABLE_FEATURE_TAR_LONG_OPTIONS && ENABLE_FEATURE_TAR_FROM
+               "\xff::" // cumulative lists for --exclude
 #endif
-
-       opt = bb_getopt_ulflags(argc, argv, tar_options,
-                               &base_dir,      /* Change to dir <optarg> */
-                               &tar_filename /* archive filename */
-#ifdef CONFIG_FEATURE_TAR_FROM
-                               , NULL,
-                               &(tar_handle->reject)
+               USE_FEATURE_TAR_CREATE("c:") "t:x:" // at least one of these is reqd
+               USE_FEATURE_TAR_CREATE("c--tx:t--cx:x--ct") // mutually exclusive
+               SKIP_FEATURE_TAR_CREATE("t--x:x--t"); // mutually exclusive
+#if ENABLE_FEATURE_TAR_LONG_OPTIONS
+       applet_long_options = tar_long_options;
 #endif
-                               );
-
-       /* Check one and only one context option was given */
-       if(opt & 0x80000000UL) {
-               bb_show_usage();
-       }
-#ifdef CONFIG_FEATURE_TAR_CREATE
-       ctx_flag = opt & (CTX_CREATE | CTX_TEST | CTX_EXTRACT);
-#else
-       ctx_flag = opt & (CTX_TEST | CTX_EXTRACT);
+       opt = getopt32(argc, argv,
+               "txC:f:Opvk"
+               USE_FEATURE_TAR_CREATE(  "ch"  )
+               USE_FEATURE_TAR_BZIP2(   "j"   )
+               USE_FEATURE_TAR_LZMA(    "a"   )
+               USE_FEATURE_TAR_FROM(    "T:X:")
+               USE_FEATURE_TAR_GZIP(    "z"   )
+               USE_FEATURE_TAR_COMPRESS("Z"   )
+               , &base_dir // -C dir
+               , &tar_filename // -f filename
+               USE_FEATURE_TAR_FROM(, &(tar_handle->accept)) // T
+               USE_FEATURE_TAR_FROM(, &(tar_handle->reject)) // X
+#if ENABLE_FEATURE_TAR_LONG_OPTIONS && ENABLE_FEATURE_TAR_FROM
+               , &excludes // --exclude
 #endif
-       if (ctx_flag == 0) {
-               bb_show_usage();
-       }
-       if(ctx_flag & CTX_TEST) {
-               if ((tar_handle->action_header == header_list) || 
-                       (tar_handle->action_header == header_verbose_list)) {
-                       tar_handle->action_header = header_verbose_list;
-               } else {
-                       tar_handle->action_header = header_list;
-               }
-       }
-       if(ctx_flag & CTX_EXTRACT) {
-               if (tar_handle->action_data != data_extract_to_stdout)
-                       tar_handle->action_data = data_extract_all;
-               }
-       if(opt & TAR_OPT_2STDOUT) {
-               /* To stdout */
+               , &verboseFlag // combined count for -t and -v
+               , &verboseFlag // combined count for -t and -v
+               );
+
+       if (verboseFlag) tar_handle->action_header = header_verbose_list;
+       if (verboseFlag == 1) tar_handle->action_header = header_list;
+
+       if (opt & OPT_EXTRACT)
+               tar_handle->action_data = data_extract_all;
+
+       if (opt & OPT_2STDOUT)
                tar_handle->action_data = data_extract_to_stdout;
-       }
-       if(opt & TAR_OPT_VERBOSE) {
-               if ((tar_handle->action_header == header_list) || 
-                       (tar_handle->action_header == header_verbose_list)) 
-               {
-               tar_handle->action_header = header_verbose_list;
-               } else {
-                       tar_handle->action_header = header_list;
-               }
-       }
-       if (opt & TAR_OPT_KEEP_OLD) {
+
+       if (opt & OPT_KEEP_OLD)
                tar_handle->flags &= ~ARCHIVE_EXTRACT_UNCONDITIONAL;
-       }
 
-#ifdef CONFIG_FEATURE_TAR_GZIP
-       if(opt & TAR_OPT_GZIP) {
+       if (opt & OPT_NOPRESERVE_OWN)
+               tar_handle->flags |= ARCHIVE_NOPRESERVE_OWN;
+
+       if (opt & OPT_NOPRESERVE_PERM)
+               tar_handle->flags |= ARCHIVE_NOPRESERVE_PERM;
+
+       if (opt & OPT_GZIP)
                get_header_ptr = get_header_tar_gz;
-       }
-#endif
-#ifdef CONFIG_FEATURE_TAR_BZIP2
-       if(opt & TAR_OPT_BZIP2) {
+
+       if (opt & OPT_BZIP2)
                get_header_ptr = get_header_tar_bz2;
-       }
-#endif
-#ifdef CONFIG_FEATURE_TAR_COMPRESS
-       if(opt & TAR_OPT_UNCOMPRESS) {
+
+       if (opt & OPT_LZMA)
+               get_header_ptr = get_header_tar_lzma;
+
+       if (opt & OPT_COMPRESS)
                get_header_ptr = get_header_tar_Z;
+
+#if ENABLE_FEATURE_TAR_FROM
+       tar_handle->reject = append_file_list_to_list(tar_handle->reject);
+#if ENABLE_FEATURE_TAR_LONG_OPTIONS
+       /* Append excludes to reject */
+       while (excludes) {
+               llist_t *next = excludes->link;
+               excludes->link = tar_handle->reject;
+               tar_handle->reject = excludes;
+               excludes = next;
        }
 #endif
-#ifdef CONFIG_FEATURE_TAR_FROM
-       if(opt & TAR_OPT_EXCLUDE_FROM) {
-               tar_handle->reject = append_file_list_to_list(tar_handle->reject);
-       }
+       tar_handle->accept = append_file_list_to_list(tar_handle->accept);
 #endif
 
        /* Check if we are reading from stdin */
-       if ((argv[optind]) && (*argv[optind] == '-')) {
+       if (argv[optind] && *argv[optind] == '-') {
                /* Default is to read from stdin, so just skip to next arg */
                optind++;
        }
 
        /* Setup an array of filenames to work with */
-       /* TODO: This is the same as in ar, seperate function ? */
+       /* TODO: This is the same as in ar, separate function ? */
        while (optind < argc) {
-               char *filename_ptr = last_char_is(argv[optind], '/');
-               if (filename_ptr) {
-                       *filename_ptr = '\0';
-               }
-               tar_handle->accept = llist_add_to(tar_handle->accept, argv[optind]);
+               /* kill trailing '/' unless the string is just "/" */
+               char *cp = last_char_is(argv[optind], '/');
+               if (cp > argv[optind])
+                       *cp = '\0';
+               llist_add_to_end(&tar_handle->accept, argv[optind]);
                optind++;
        }
 
-       if ((tar_handle->accept) || (tar_handle->reject)) {
+       if (tar_handle->accept || tar_handle->reject)
                tar_handle->filter = filter_accept_reject_list;
-       }
 
        /* Open the tar file */
        {
                FILE *tar_stream;
                int flags;
 
-#ifdef CONFIG_FEATURE_TAR_CREATE
-               if (opt & CTX_CREATE) {
+               if (opt & OPT_CREATE) {
                        /* Make sure there is at least one file to tar up.  */
-                       if (tar_handle->accept == NULL) {
-                               bb_error_msg_and_die("Cowardly refusing to create an empty archive");
-                       }
+                       if (tar_handle->accept == NULL)
+                               bb_error_msg_and_die("empty archive");
+
                        tar_stream = stdout;
-                       flags = O_WRONLY | O_CREAT | O_EXCL;
-                       unlink(tar_filename);
-               } else
-#endif
-               {
+                       /* Mimicking GNU tar 1.15.1: */
+                       flags = O_WRONLY|O_CREAT|O_TRUNC;
+               /* was doing unlink; open(O_WRONLY|O_CREAT|O_EXCL); why? */
+               } else {
                        tar_stream = stdin;
                        flags = O_RDONLY;
                }
 
-               if ((tar_filename[0] == '-') && (tar_filename[1] == '\0')) {
+               if (LONE_DASH(tar_filename)) {
                        tar_handle->src_fd = fileno(tar_stream);
-                       tar_handle->seek = seek_by_char;
+                       tar_handle->seek = seek_by_read;
                } else {
-                       tar_handle->src_fd = bb_xopen(tar_filename, flags);
+                       tar_handle->src_fd = xopen(tar_filename, flags);
                }
        }
 
-       if ((base_dir) && (chdir(base_dir))) {
-               bb_perror_msg_and_die("Couldnt chdir to %s", base_dir);
-       }
-
-#ifdef CONFIG_FEATURE_TAR_CREATE
-       /* create an archive */
-       if (opt & CTX_CREATE) {
-               int verboseFlag = FALSE;
-               int gzipFlag = FALSE;
+       if (base_dir)
+               xchdir(base_dir);
 
-# ifdef CONFIG_FEATURE_TAR_GZIP
-               if (get_header_ptr == get_header_tar_gz) {
-                       gzipFlag = TRUE;
-               }
-# endif /* CONFIG_FEATURE_TAR_GZIP */
-# ifdef CONFIG_FEATURE_TAR_BZIP2
-               if (get_header_ptr == get_header_tar_bz2) {
-                       bb_error_msg_and_die("Creating bzip2 compressed archives is not currently supported.");
-               }
-# endif /* CONFIG_FEATURE_TAR_BZIP2 */
+#ifdef CHECK_FOR_CHILD_EXITCODE
+       /* We need to know whether child (gzip/bzip/etc) exits abnormally */
+       signal(SIGCHLD, handle_SIGCHLD);
+#endif
 
-               if ((tar_handle->action_header == header_list) || 
-                               (tar_handle->action_header == header_verbose_list)) {
-                       verboseFlag = TRUE;
-               }
-               writeTarFile(tar_handle->src_fd, verboseFlag, tar_handle->accept,
-                       tar_handle->reject, gzipFlag);
-       } else 
-#endif /* CONFIG_FEATURE_TAR_CREATE */
-       {
-               while (get_header_ptr(tar_handle) == EXIT_SUCCESS);
-
-               /* Ckeck that every file that should have been extracted was */
-               while (tar_handle->accept) {
-                       if (find_list_entry(tar_handle->reject, tar_handle->accept->data) == NULL) {
-                               if (find_list_entry(tar_handle->passed, tar_handle->accept->data) == NULL) {
-                                       bb_error_msg_and_die("%s: Not found in archive\n", tar_handle->accept->data);
-                               }
-                       }
-                       tar_handle->accept = tar_handle->accept->link;
+       /* create an archive */
+       if (opt & OPT_CREATE) {
+               int zipMode = 0;
+               if (ENABLE_FEATURE_TAR_GZIP && get_header_ptr == get_header_tar_gz)
+                       zipMode = 1;
+               if (ENABLE_FEATURE_TAR_BZIP2 && get_header_ptr == get_header_tar_bz2)
+                       zipMode = 2;
+               /* NB: writeTarFile() closes tar_handle->src_fd */
+               return writeTarFile(tar_handle->src_fd, verboseFlag, opt & OPT_DEREFERENCE,
+                               tar_handle->accept,
+                               tar_handle->reject, zipMode);
+       }
+
+       while (get_header_ptr(tar_handle) == EXIT_SUCCESS)
+               /* nothing */;
+
+       /* Check that every file that should have been extracted was */
+       while (tar_handle->accept) {
+               if (!find_list_entry(tar_handle->reject, tar_handle->accept->data)
+                && !find_list_entry(tar_handle->passed, tar_handle->accept->data)
+               ) {
+                       bb_error_msg_and_die("%s: not found in archive",
+                               tar_handle->accept->data);
                }
+               tar_handle->accept = tar_handle->accept->link;
        }
-
-#ifdef CONFIG_FEATURE_CLEAN_UP
-       if (tar_handle->src_fd != fileno(stdin)) {
+       if (ENABLE_FEATURE_CLEAN_UP /* && tar_handle->src_fd != STDIN_FILENO */)
                close(tar_handle->src_fd);
-       }
-#endif /* CONFIG_FEATURE_CLEAN_UP */
 
-       return(EXIT_SUCCESS);
+       return EXIT_SUCCESS;
 }