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-rw-r--r--tar.c1425
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diff --git a/tar.c b/tar.c
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+++ b/tar.c
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+/*
+ * Copyright (c) 1999 by David I. Bell
+ * Permission is granted to use, distribute, or modify this source,
+ * provided that this copyright notice remains intact.
+ *
+ * The "tar" command, taken from sash.
+ * This allows creation, extraction, and listing of tar files.
+ *
+ * Permission to distribute this code under the GPL has been granted.
+ * Modified for busybox by Erik Andersen <andersee@debian.org> <andersen@lineo.com>
+ */
+
+
+#include "internal.h"
+
+#ifdef BB_TAR
+
+const char tar_usage[] =
+"Create, extract, or list files from a TAR file\n\n"
+"usage: tar -[cxtvOf] [tarFileName] [FILE] ...\n"
+"\tc=create, x=extract, t=list contents, v=verbose,\n"
+"\tO=extract to stdout, f=tarfile or \"-\" for stdin\n";
+
+
+
+#include <stdio.h>
+#include <dirent.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <signal.h>
+#include <time.h>
+
+/*
+ * Tar file constants.
+ */
+#define TAR_BLOCK_SIZE 512
+#define TAR_NAME_SIZE 100
+
+
+/*
+ * The POSIX (and basic GNU) tar header format.
+ * This structure is always embedded in a TAR_BLOCK_SIZE sized block
+ * with zero padding. We only process this information minimally.
+ */
+typedef struct
+{
+ char name[TAR_NAME_SIZE];
+ char mode[8];
+ char uid[8];
+ char gid[8];
+ char size[12];
+ char mtime[12];
+ char checkSum[8];
+ char typeFlag;
+ char linkName[TAR_NAME_SIZE];
+ char magic[6];
+ char version[2];
+ char uname[32];
+ char gname[32];
+ char devMajor[8];
+ char devMinor[8];
+ char prefix[155];
+} TarHeader;
+
+#define TAR_MAGIC "ustar"
+#define TAR_VERSION "00"
+
+#define TAR_TYPE_REGULAR '0'
+#define TAR_TYPE_HARD_LINK '1'
+#define TAR_TYPE_SOFT_LINK '2'
+
+
+/*
+ * Static data.
+ */
+static BOOL listFlag;
+static BOOL extractFlag;
+static BOOL createFlag;
+static BOOL verboseFlag;
+static BOOL tostdoutFlag;
+
+static BOOL inHeader;
+static BOOL badHeader;
+static BOOL errorFlag;
+static BOOL skipFileFlag;
+static BOOL warnedRoot;
+static BOOL eofFlag;
+static long dataCc;
+static int outFd;
+static char outName[TAR_NAME_SIZE];
+
+
+/*
+ * Static data associated with the tar file.
+ */
+static const char * tarName;
+static int tarFd;
+static dev_t tarDev;
+static ino_t tarInode;
+
+
+/*
+ * Local procedures to restore files from a tar file.
+ */
+static void readTarFile(int fileCount, char ** fileTable);
+static void readData(const char * cp, int count);
+static void createPath(const char * name, int mode);
+static long getOctal(const char * cp, int len);
+
+static void readHeader(const TarHeader * hp,
+ int fileCount, char ** fileTable);
+
+
+/*
+ * Local procedures to save files into a tar file.
+ */
+static void saveFile(const char * fileName, BOOL seeLinks);
+
+static void saveRegularFile(const char * fileName,
+ const struct stat * statbuf);
+
+static void saveDirectory(const char * fileName,
+ const struct stat * statbuf);
+
+static BOOL wantFileName(const char * fileName,
+ int fileCount, char ** fileTable);
+
+static void writeHeader(const char * fileName,
+ const struct stat * statbuf);
+
+static void writeTarFile(int fileCount, char ** fileTable);
+static void writeTarBlock(const char * buf, int len);
+static BOOL putOctal(char * cp, int len, long value);
+extern const char * modeString(int mode);
+extern const char * timeString(time_t timeVal);
+extern int fullWrite(int fd, const char * buf, int len);
+extern int fullRead(int fd, char * buf, int len);
+
+
+extern int
+tar_main(struct FileInfo *unused, int argc, char ** argv)
+{
+ const char * options;
+
+ argc--;
+ argv++;
+
+ if (argc < 1)
+ {
+ fprintf(stderr, "%s", tar_usage);
+ return 1;
+ }
+
+
+ errorFlag = FALSE;
+ extractFlag = FALSE;
+ createFlag = FALSE;
+ listFlag = FALSE;
+ verboseFlag = FALSE;
+ tostdoutFlag = FALSE;
+ tarName = NULL;
+ tarDev = 0;
+ tarInode = 0;
+ tarFd = -1;
+
+ /*
+ * Parse the options.
+ */
+ options = *argv++;
+ argc--;
+
+ if (**argv == '-') {
+ for (; *options; options++)
+ {
+ switch (*options)
+ {
+ case 'f':
+ if (tarName != NULL)
+ {
+ fprintf(stderr, "Only one 'f' option allowed\n");
+
+ return 1;
+ }
+
+ tarName = *argv++;
+ argc--;
+
+ break;
+
+ case 't':
+ listFlag = TRUE;
+ break;
+
+ case 'x':
+ extractFlag = TRUE;
+ break;
+
+ case 'c':
+ createFlag = TRUE;
+ break;
+
+ case 'v':
+ verboseFlag = TRUE;
+ break;
+
+ case 'O':
+ tostdoutFlag = TRUE;
+ break;
+
+ case '-':
+ break;
+
+ default:
+ fprintf(stderr, "Unknown tar flag '%c'\n", *options);
+
+ return 1;
+ }
+ }
+ }
+
+ /*
+ * Validate the options.
+ */
+ if (extractFlag + listFlag + createFlag != 1)
+ {
+ fprintf(stderr, "Exactly one of 'c', 'x' or 't' must be specified\n");
+
+ return 1;
+ }
+
+ /*
+ * Do the correct type of action supplying the rest of the
+ * command line arguments as the list of files to process.
+ */
+ if (createFlag)
+ writeTarFile(argc, argv);
+ else
+ readTarFile(argc, argv);
+ if (errorFlag)
+ fprintf(stderr, "\n");
+ return( errorFlag);
+}
+
+
+/*
+ * Read a tar file and extract or list the specified files within it.
+ * If the list is empty than all files are extracted or listed.
+ */
+static void
+readTarFile(int fileCount, char ** fileTable)
+{
+ const char * cp;
+ int cc;
+ int inCc;
+ int blockSize;
+ char buf[BUF_SIZE];
+
+ skipFileFlag = FALSE;
+ badHeader = FALSE;
+ warnedRoot = FALSE;
+ eofFlag = FALSE;
+ inHeader = TRUE;
+ inCc = 0;
+ dataCc = 0;
+ outFd = -1;
+ blockSize = sizeof(buf);
+ cp = buf;
+
+ /*
+ * Open the tar file for reading.
+ */
+ if ( (tarName==NULL) || !strcmp( tarName, "-") ) {
+ tarFd = STDIN;
+ }
+ else
+ tarFd = open(tarName, O_RDONLY);
+
+ if (tarFd < 0)
+ {
+ perror(tarName);
+ errorFlag = TRUE;
+ return;
+ }
+
+ /*
+ * Read blocks from the file until an end of file header block
+ * has been seen. (A real end of file from a read is an error.)
+ */
+ while (!eofFlag)
+ {
+ /*
+ * Read the next block of data if necessary.
+ * This will be a large block if possible, which we will
+ * then process in the small tar blocks.
+ */
+ if (inCc <= 0)
+ {
+ cp = buf;
+ inCc = fullRead(tarFd, buf, blockSize);
+
+ if (inCc < 0)
+ {
+ perror(tarName);
+ errorFlag=TRUE;
+ goto done;
+ }
+
+ if (inCc == 0)
+ {
+ fprintf(stderr,
+ "Unexpected end of file from \"%s\"",
+ tarName);
+ errorFlag=TRUE;
+ goto done;
+ }
+ }
+
+ /*
+ * If we are expecting a header block then examine it.
+ */
+ if (inHeader)
+ {
+ readHeader((const TarHeader *) cp, fileCount, fileTable);
+
+ cp += TAR_BLOCK_SIZE;
+ inCc -= TAR_BLOCK_SIZE;
+
+ continue;
+ }
+
+ /*
+ * We are currently handling the data for a file.
+ * Process the minimum of the amount of data we have available
+ * and the amount left to be processed for the file.
+ */
+ cc = inCc;
+
+ if (cc > dataCc)
+ cc = dataCc;
+
+ readData(cp, cc);
+
+ /*
+ * If the amount left isn't an exact multiple of the tar block
+ * size then round it up to the next block boundary since there
+ * is padding at the end of the file.
+ */
+ if (cc % TAR_BLOCK_SIZE)
+ cc += TAR_BLOCK_SIZE - (cc % TAR_BLOCK_SIZE);
+
+ cp += cc;
+ inCc -= cc;
+ }
+
+done:
+ /*
+ * Close the tar file if needed.
+ */
+ if ((tarFd >= 0) && (close(tarFd) < 0))
+ perror(tarName);
+
+ /*
+ * Close the output file if needed.
+ * This is only done here on a previous error and so no
+ * message is required on errors.
+ */
+ if (tostdoutFlag==FALSE) {
+ if (outFd >= 0)
+ (void) close(outFd);
+ }
+}
+
+
+/*
+ * Examine the header block that was just read.
+ * This can specify the information for another file, or it can mark
+ * the end of the tar file.
+ */
+static void
+readHeader(const TarHeader * hp, int fileCount, char ** fileTable)
+{
+ int mode;
+ int uid;
+ int gid;
+ int checkSum;
+ long size;
+ time_t mtime;
+ const char * name;
+ int cc;
+ BOOL hardLink;
+ BOOL softLink;
+
+ /*
+ * If the block is completely empty, then this is the end of the
+ * archive file. If the name is null, then just skip this header.
+ */
+ name = hp->name;
+
+ if (*name == '\0')
+ {
+ for (cc = TAR_BLOCK_SIZE; cc > 0; cc--)
+ {
+ if (*name++)
+ return;
+ }
+
+ eofFlag = TRUE;
+
+ return;
+ }
+
+ /*
+ * There is another file in the archive to examine.
+ * Extract the encoded information and check it.
+ */
+ mode = getOctal(hp->mode, sizeof(hp->mode));
+ uid = getOctal(hp->uid, sizeof(hp->uid));
+ gid = getOctal(hp->gid, sizeof(hp->gid));
+ size = getOctal(hp->size, sizeof(hp->size));
+ mtime = getOctal(hp->mtime, sizeof(hp->mtime));
+ checkSum = getOctal(hp->checkSum, sizeof(hp->checkSum));
+
+ if ((mode < 0) || (uid < 0) || (gid < 0) || (size < 0))
+ {
+ if (!badHeader)
+ fprintf(stderr, "Bad tar header, skipping\n");
+
+ badHeader = TRUE;
+
+ return;
+ }
+
+ badHeader = FALSE;
+ skipFileFlag = FALSE;
+
+ /*
+ * Check for the file modes.
+ */
+ hardLink = ((hp->typeFlag == TAR_TYPE_HARD_LINK) ||
+ (hp->typeFlag == TAR_TYPE_HARD_LINK - '0'));
+
+ softLink = ((hp->typeFlag == TAR_TYPE_SOFT_LINK) ||
+ (hp->typeFlag == TAR_TYPE_SOFT_LINK - '0'));
+
+ /*
+ * Check for a directory or a regular file.
+ */
+ if (name[strlen(name) - 1] == '/')
+ mode |= S_IFDIR;
+ else if ((mode & S_IFMT) == 0)
+ mode |= S_IFREG;
+
+ /*
+ * Check for absolute paths in the file.
+ * If we find any, then warn the user and make them relative.
+ */
+ if (*name == '/')
+ {
+ while (*name == '/')
+ name++;
+
+ if (!warnedRoot)
+ {
+ fprintf(stderr,
+ "Absolute path detected, removing leading slashes\n");
+ }
+
+ warnedRoot = TRUE;
+ }
+
+ /*
+ * See if we want this file to be restored.
+ * If not, then set up to skip it.
+ */
+ if (!wantFileName(name, fileCount, fileTable))
+ {
+ if (!hardLink && !softLink && S_ISREG(mode))
+ {
+ inHeader = (size == 0);
+ dataCc = size;
+ }
+
+ skipFileFlag = TRUE;
+
+ return;
+ }
+
+ /*
+ * This file is to be handled.
+ * If we aren't extracting then just list information about the file.
+ */
+ if (!extractFlag)
+ {
+ if (verboseFlag)
+ {
+ printf("%s %3d/%-d %9ld %s %s", modeString(mode),
+ uid, gid, size, timeString(mtime), name);
+ }
+ else
+ printf("%s", name);
+
+ if (hardLink)
+ printf(" (link to \"%s\")", hp->linkName);
+ else if (softLink)
+ printf(" (symlink to \"%s\")", hp->linkName);
+ else if (S_ISREG(mode))
+ {
+ inHeader = (size == 0);
+ dataCc = size;
+ }
+
+ printf("\n");
+
+ return;
+ }
+
+ /*
+ * We really want to extract the file.
+ */
+ if (verboseFlag)
+ printf("x %s\n", name);
+
+ if (hardLink)
+ {
+ if (link(hp->linkName, name) < 0)
+ perror(name);
+
+ return;
+ }
+
+ if (softLink)
+ {
+#ifdef S_ISLNK
+ if (symlink(hp->linkName, name) < 0)
+ perror(name);
+#else
+ fprintf(stderr, "Cannot create symbolic links\n");
+#endif
+ return;
+ }
+
+ /*
+ * If the file is a directory, then just create the path.
+ */
+ if (S_ISDIR(mode))
+ {
+ createPath(name, mode);
+
+ return;
+ }
+
+ /*
+ * There is a file to write.
+ * First create the path to it if necessary with a default permission.
+ */
+ createPath(name, 0777);
+
+ inHeader = (size == 0);
+ dataCc = size;
+
+ /*
+ * Start the output file.
+ */
+ if (tostdoutFlag==TRUE)
+ outFd = STDOUT;
+ else
+ outFd = open(name, O_WRONLY | O_CREAT | O_TRUNC, mode);
+
+ if (outFd < 0)
+ {
+ perror(name);
+ skipFileFlag = TRUE;
+ return;
+ }
+
+ /*
+ * If the file is empty, then that's all we need to do.
+ */
+ if (size == 0 && tostdoutFlag == FALSE)
+ {
+ (void) close(outFd);
+ outFd = -1;
+ }
+}
+
+
+/*
+ * Handle a data block of some specified size that was read.
+ */
+static void
+readData(const char * cp, int count)
+{
+ /*
+ * Reduce the amount of data left in this file.
+ * If there is no more data left, then we need to read
+ * the header again.
+ */
+ dataCc -= count;
+
+ if (dataCc <= 0)
+ inHeader = TRUE;
+
+ /*
+ * If we aren't extracting files or this file is being
+ * skipped then do nothing more.
+ */
+ if (!extractFlag || skipFileFlag)
+ return;
+
+ /*
+ * Write the data to the output file.
+ */
+ if (fullWrite(outFd, cp, count) < 0)
+ {
+ perror(outName);
+ if (tostdoutFlag==FALSE) {
+ (void) close(outFd);
+ outFd = -1;
+ }
+ skipFileFlag = TRUE;
+ return;
+ }
+
+ /*
+ * If the write failed, close the file and disable further
+ * writes to this file.
+ */
+ if (dataCc <= 0 && tostdoutFlag==FALSE)
+ {
+ if (close(outFd))
+ perror(outName);
+
+ outFd = -1;
+ }
+}
+
+
+/*
+ * Write a tar file containing the specified files.
+ */
+static void
+writeTarFile(int fileCount, char ** fileTable)
+{
+ struct stat statbuf;
+
+ /*
+ * Make sure there is at least one file specified.
+ */
+ if (fileCount <= 0)
+ {
+ fprintf(stderr, "No files specified to be saved\n");
+ errorFlag=TRUE;
+ }
+
+ /*
+ * Create the tar file for writing.
+ */
+ if ( (tarName==NULL) || !strcmp( tarName, "-") ) {
+ tostdoutFlag = TRUE;
+ tarFd = STDOUT;
+ }
+ else
+ tarFd = open(tarName, O_WRONLY | O_CREAT | O_TRUNC, 0666);
+
+ if (tarFd < 0)
+ {
+ perror(tarName);
+ errorFlag=TRUE;
+ return;
+ }
+
+ /*
+ * Get the device and inode of the tar file for checking later.
+ */
+ if (fstat(tarFd, &statbuf) < 0)
+ {
+ perror(tarName);
+ errorFlag = TRUE;
+ goto done;
+ }
+
+ tarDev = statbuf.st_dev;
+ tarInode = statbuf.st_ino;
+
+ /*
+ * Append each file name into the archive file.
+ * Follow symbolic links for these top level file names.
+ */
+ while (!errorFlag && (fileCount-- > 0))
+ {
+ saveFile(*fileTable++, FALSE);
+ }
+
+ /*
+ * Now write an empty block of zeroes to end the archive.
+ */
+ writeTarBlock("", 1);
+
+
+done:
+ /*
+ * Close the tar file and check for errors if it was opened.
+ */
+ if ( (tostdoutFlag==FALSE) && (tarFd >= 0) && (close(tarFd) < 0))
+ perror(tarName);
+}
+
+
+/*
+ * Save one file into the tar file.
+ * If the file is a directory, then this will recursively save all of
+ * the files and directories within the directory. The seeLinks
+ * flag indicates whether or not we want to see symbolic links as
+ * they really are, instead of blindly following them.
+ */
+static void
+saveFile(const char * fileName, BOOL seeLinks)
+{
+ int status;
+ int mode;
+ struct stat statbuf;
+
+ if (verboseFlag)
+ printf("a %s\n", fileName);
+
+ /*
+ * Check that the file name will fit in the header.
+ */
+ if (strlen(fileName) >= TAR_NAME_SIZE)
+ {
+ fprintf(stderr, "%s: File name is too long\n", fileName);
+
+ return;
+ }
+
+ /*
+ * Find out about the file.
+ */
+#ifdef S_ISLNK
+ if (seeLinks)
+ status = lstat(fileName, &statbuf);
+ else
+#endif
+ status = stat(fileName, &statbuf);
+
+ if (status < 0)
+ {
+ perror(fileName);
+
+ return;
+ }
+
+ /*
+ * Make sure we aren't trying to save our file into itself.
+ */
+ if ((statbuf.st_dev == tarDev) && (statbuf.st_ino == tarInode))
+ {
+ fprintf(stderr, "Skipping saving of archive file itself\n");
+
+ return;
+ }
+
+ /*
+ * Check the type of file.
+ */
+ mode = statbuf.st_mode;
+
+ if (S_ISDIR(mode))
+ {
+ saveDirectory(fileName, &statbuf);
+
+ return;
+ }
+
+ if (S_ISREG(mode))
+ {
+ saveRegularFile(fileName, &statbuf);
+
+ return;
+ }
+
+ /*
+ * The file is a strange type of file, ignore it.
+ */
+ fprintf(stderr, "%s: not a directory or regular file\n", fileName);
+}
+
+
+/*
+ * Save a regular file to the tar file.
+ */
+static void
+saveRegularFile(const char * fileName, const struct stat * statbuf)
+{
+ BOOL sawEof;
+ int fileFd;
+ int cc;
+ int dataCount;
+ long fullDataCount;
+ char data[TAR_BLOCK_SIZE * 16];
+
+ /*
+ * Open the file for reading.
+ */
+ fileFd = open(fileName, O_RDONLY);
+
+ if (fileFd < 0)
+ {
+ perror(fileName);
+
+ return;
+ }
+
+ /*
+ * Write out the header for the file.
+ */
+ writeHeader(fileName, statbuf);
+
+ /*
+ * Write the data blocks of the file.
+ * We must be careful to write the amount of data that the stat
+ * buffer indicated, even if the file has changed size. Otherwise
+ * the tar file will be incorrect.
+ */
+ fullDataCount = statbuf->st_size;
+ sawEof = FALSE;
+
+ while (fullDataCount > 0)
+ {
+ /*
+ * Get the amount to write this iteration which is
+ * the minumum of the amount left to write and the
+ * buffer size.
+ */
+ dataCount = sizeof(data);
+
+ if (dataCount > fullDataCount)
+ dataCount = (int) fullDataCount;
+
+ /*
+ * Read the data from the file if we haven't seen the
+ * end of file yet.
+ */
+ cc = 0;
+
+ if (!sawEof)
+ {
+ cc = fullRead(fileFd, data, dataCount);
+
+ if (cc < 0)
+ {
+ perror(fileName);
+
+ (void) close(fileFd);
+ errorFlag = TRUE;
+
+ return;
+ }
+
+ /*
+ * If the file ended too soon, complain and set
+ * a flag so we will zero fill the rest of it.
+ */
+ if (cc < dataCount)
+ {
+ fprintf(stderr,
+ "%s: Short read - zero filling",
+ fileName);
+
+ sawEof = TRUE;
+ }
+ }
+
+ /*
+ * Zero fill the rest of the data if necessary.
+ */
+ if (cc < dataCount)
+ memset(data + cc, 0, dataCount - cc);
+
+ /*
+ * Write the buffer to the TAR file.
+ */
+ writeTarBlock(data, dataCount);
+
+ fullDataCount -= dataCount;
+ }
+
+ /*
+ * Close the file.
+ */
+ if ( (tostdoutFlag==FALSE) && close(fileFd) < 0)
+ fprintf(stderr, "%s: close: %s\n", fileName, strerror(errno));
+}
+
+
+/*
+ * Save a directory and all of its files to the tar file.
+ */
+static void
+saveDirectory(const char * dirName, const struct stat * statbuf)
+{
+ DIR * dir;
+ struct dirent * entry;
+ BOOL needSlash;
+ char fullName[PATH_LEN];
+
+ /*
+ * Construct the directory name as used in the tar file by appending
+ * a slash character to it.
+ */
+ strcpy(fullName, dirName);
+ strcat(fullName, "/");
+
+ /*
+ * Write out the header for the directory entry.
+ */
+ writeHeader(fullName, statbuf);
+
+ /*
+ * Open the directory.
+ */
+ dir = opendir(dirName);
+
+ if (dir == NULL)
+ {
+ fprintf(stderr, "Cannot read directory \"%s\": %s\n",
+ dirName, strerror(errno));
+
+ return;
+ }
+
+ /*
+ * See if a slash is needed.
+ */
+ needSlash = (*dirName && (dirName[strlen(dirName) - 1] != '/'));
+
+ /*
+ * Read all of the directory entries and check them,
+ * except for the current and parent directory entries.
+ */
+ while (!errorFlag && ((entry = readdir(dir)) != NULL))
+ {
+ if ((strcmp(entry->d_name, ".") == 0) ||
+ (strcmp(entry->d_name, "..") == 0))
+ {
+ continue;
+ }
+
+ /*
+ * Build the full path name to the file.
+ */
+ strcpy(fullName, dirName);
+
+ if (needSlash)
+ strcat(fullName, "/");
+
+ strcat(fullName, entry->d_name);
+
+ /*
+ * Write this file to the tar file, noticing whether or not
+ * the file is a symbolic link.
+ */
+ saveFile(fullName, TRUE);
+ }
+
+ /*
+ * All done, close the directory.
+ */
+ closedir(dir);
+}
+
+
+/*
+ * Write a tar header for the specified file name and status.
+ * It is assumed that the file name fits.
+ */
+static void
+writeHeader(const char * fileName, const struct stat * statbuf)
+{
+ long checkSum;
+ const unsigned char * cp;
+ int len;
+ TarHeader header;
+
+ /*
+ * Zero the header block in preparation for filling it in.
+ */
+ memset((char *) &header, 0, sizeof(header));
+
+ /*
+ * Fill in the header.
+ */
+ strcpy(header.name, fileName);
+
+ strncpy(header.magic, TAR_MAGIC, sizeof(header.magic));
+ strncpy(header.version, TAR_VERSION, sizeof(header.version));
+
+ putOctal(header.mode, sizeof(header.mode), statbuf->st_mode & 0777);
+ putOctal(header.uid, sizeof(header.uid), statbuf->st_uid);
+ putOctal(header.gid, sizeof(header.gid), statbuf->st_gid);
+ putOctal(header.size, sizeof(header.size), statbuf->st_size);
+ putOctal(header.mtime, sizeof(header.mtime), statbuf->st_mtime);
+
+ header.typeFlag = TAR_TYPE_REGULAR;
+
+ /*
+ * Calculate and store the checksum.
+ * This is the sum of all of the bytes of the header,
+ * with the checksum field itself treated as blanks.
+ */
+ memset(header.checkSum, ' ', sizeof(header.checkSum));
+
+ cp = (const unsigned char *) &header;
+ len = sizeof(header);
+ checkSum = 0;
+
+ while (len-- > 0)
+ checkSum += *cp++;
+
+ putOctal(header.checkSum, sizeof(header.checkSum), checkSum);
+
+ /*
+ * Write the tar header.
+ */
+ writeTarBlock((const char *) &header, sizeof(header));
+}
+
+
+/*
+ * Write data to one or more blocks of the tar file.
+ * The data is always padded out to a multiple of TAR_BLOCK_SIZE.
+ * The errorFlag static variable is set on an error.
+ */
+static void
+writeTarBlock(const char * buf, int len)
+{
+ int partialLength;
+ int completeLength;
+ char fullBlock[TAR_BLOCK_SIZE];
+
+ /*
+ * If we had a write error before, then do nothing more.
+ */
+ if (errorFlag)
+ return;
+
+ /*
+ * Get the amount of complete and partial blocks.
+ */
+ partialLength = len % TAR_BLOCK_SIZE;
+ completeLength = len - partialLength;
+
+ /*
+ * Write all of the complete blocks.
+ */
+ if ((completeLength > 0) && !fullWrite(tarFd, buf, completeLength))
+ {
+ perror(tarName);
+
+ errorFlag = TRUE;
+
+ return;
+ }
+
+ /*
+ * If there are no partial blocks left, we are done.
+ */
+ if (partialLength == 0)
+ return;
+
+ /*
+ * Copy the partial data into a complete block, and pad the rest
+ * of it with zeroes.
+ */
+ memcpy(fullBlock, buf + completeLength, partialLength);
+ memset(fullBlock + partialLength, 0, TAR_BLOCK_SIZE - partialLength);
+
+ /*
+ * Write the last complete block.
+ */
+ if (!fullWrite(tarFd, fullBlock, TAR_BLOCK_SIZE))
+ {
+ perror(tarName);
+
+ errorFlag = TRUE;
+ }
+}
+
+
+/*
+ * Attempt to create the directories along the specified path, except for
+ * the final component. The mode is given for the final directory only,
+ * while all previous ones get default protections. Errors are not reported
+ * here, as failures to restore files can be reported later.
+ */
+static void
+createPath(const char * name, int mode)
+{
+ char * cp;
+ char * cpOld;
+ char buf[TAR_NAME_SIZE];
+
+ strcpy(buf, name);
+
+ cp = strchr(buf, '/');
+
+ while (cp)
+ {
+ cpOld = cp;
+ cp = strchr(cp + 1, '/');
+
+ *cpOld = '\0';
+
+ if (mkdir(buf, cp ? 0777 : mode) == 0)
+ printf("Directory \"%s\" created\n", buf);
+
+ *cpOld = '/';
+ }
+}
+
+
+/*
+ * Read an octal value in a field of the specified width, with optional
+ * spaces on both sides of the number and with an optional null character
+ * at the end. Returns -1 on an illegal format.
+ */
+static long
+getOctal(const char * cp, int len)
+{
+ long val;
+
+ while ((len > 0) && (*cp == ' '))
+ {
+ cp++;
+ len--;
+ }
+
+ if ((len == 0) || !isOctal(*cp))
+ return -1;
+
+ val = 0;
+
+ while ((len > 0) && isOctal(*cp))
+ {
+ val = val * 8 + *cp++ - '0';
+ len--;
+ }
+
+ while ((len > 0) && (*cp == ' '))
+ {
+ cp++;
+ len--;
+ }
+
+ if ((len > 0) && *cp)
+ return -1;
+
+ return val;
+}
+
+
+/*
+ * Put an octal string into the specified buffer.
+ * The number is zero and space padded and possibly null padded.
+ * Returns TRUE if successful.
+ */
+static BOOL
+putOctal(char * cp, int len, long value)
+{
+ int tempLength;
+ char * tempString;
+ char tempBuffer[32];
+
+ /*
+ * Create a string of the specified length with an initial space,
+ * leading zeroes and the octal number, and a trailing null.
+ */
+ tempString = tempBuffer;
+
+ sprintf(tempString, " %0*lo", len - 2, value);
+
+ tempLength = strlen(tempString) + 1;
+
+ /*
+ * If the string is too large, suppress the leading space.
+ */
+ if (tempLength > len)
+ {
+ tempLength--;
+ tempString++;
+ }
+
+ /*
+ * If the string is still too large, suppress the trailing null.
+ */
+ if (tempLength > len)
+ tempLength--;
+
+ /*
+ * If the string is still too large, fail.
+ */
+ if (tempLength > len)
+ return FALSE;
+
+ /*
+ * Copy the string to the field.
+ */
+ memcpy(cp, tempString, len);
+
+ return TRUE;
+}
+
+
+/*
+ * See if the specified file name belongs to one of the specified list
+ * of path prefixes. An empty list implies that all files are wanted.
+ * Returns TRUE if the file is selected.
+ */
+static BOOL
+wantFileName(const char * fileName, int fileCount, char ** fileTable)
+{
+ const char * pathName;
+ int fileLength;
+ int pathLength;
+
+ /*
+ * If there are no files in the list, then the file is wanted.
+ */
+ if (fileCount == 0)
+ return TRUE;
+
+ fileLength = strlen(fileName);
+
+ /*
+ * Check each of the test paths.
+ */
+ while (fileCount-- > 0)
+ {
+ pathName = *fileTable++;
+
+ pathLength = strlen(pathName);
+
+ if (fileLength < pathLength)
+ continue;
+
+ if (memcmp(fileName, pathName, pathLength) != 0)
+ continue;
+
+ if ((fileLength == pathLength) ||
+ (fileName[pathLength] == '/'))
+ {
+ return TRUE;
+ }
+ }
+
+ return FALSE;
+}
+
+
+
+/*
+ * Return the standard ls-like mode string from a file mode.
+ * This is static and so is overwritten on each call.
+ */
+const char *
+modeString(int mode)
+{
+ static char buf[12];
+
+ strcpy(buf, "----------");
+
+ /*
+ * Fill in the file type.
+ */
+ if (S_ISDIR(mode))
+ buf[0] = 'd';
+ if (S_ISCHR(mode))
+ buf[0] = 'c';
+ if (S_ISBLK(mode))
+ buf[0] = 'b';
+ if (S_ISFIFO(mode))
+ buf[0] = 'p';
+#ifdef S_ISLNK
+ if (S_ISLNK(mode))
+ buf[0] = 'l';
+#endif
+#ifdef S_ISSOCK
+ if (S_ISSOCK(mode))
+ buf[0] = 's';
+#endif
+
+ /*
+ * Now fill in the normal file permissions.
+ */
+ if (mode & S_IRUSR)
+ buf[1] = 'r';
+ if (mode & S_IWUSR)
+ buf[2] = 'w';
+ if (mode & S_IXUSR)
+ buf[3] = 'x';
+ if (mode & S_IRGRP)
+ buf[4] = 'r';
+ if (mode & S_IWGRP)
+ buf[5] = 'w';
+ if (mode & S_IXGRP)
+ buf[6] = 'x';
+ if (mode & S_IROTH)
+ buf[7] = 'r';
+ if (mode & S_IWOTH)
+ buf[8] = 'w';
+ if (mode & S_IXOTH)
+ buf[9] = 'x';
+
+ /*
+ * Finally fill in magic stuff like suid and sticky text.
+ */
+ if (mode & S_ISUID)
+ buf[3] = ((mode & S_IXUSR) ? 's' : 'S');
+ if (mode & S_ISGID)
+ buf[6] = ((mode & S_IXGRP) ? 's' : 'S');
+ if (mode & S_ISVTX)
+ buf[9] = ((mode & S_IXOTH) ? 't' : 'T');
+
+ return buf;
+}
+
+
+/*
+ * Get the time string to be used for a file.
+ * This is down to the minute for new files, but only the date for old files.
+ * The string is returned from a static buffer, and so is overwritten for
+ * each call.
+ */
+const char *
+timeString(time_t timeVal)
+{
+ time_t now;
+ char * str;
+ static char buf[26];
+
+ time(&now);
+
+ str = ctime(&timeVal);
+
+ strcpy(buf, &str[4]);
+ buf[12] = '\0';
+
+ if ((timeVal > now) || (timeVal < now - 365*24*60*60L))
+ {
+ strcpy(&buf[7], &str[20]);
+ buf[11] = '\0';
+ }
+
+ return buf;
+}
+
+
+
+/*
+ * Write all of the supplied buffer out to a file.
+ * This does multiple writes as necessary.
+ * Returns the amount written, or -1 on an error.
+ */
+int
+fullWrite(int fd, const char * buf, int len)
+{
+ int cc;
+ int total;
+
+ total = 0;
+
+ while (len > 0)
+ {
+ cc = write(fd, buf, len);
+
+ if (cc < 0)
+ return -1;
+
+ buf += cc;
+ total+= cc;
+ len -= cc;
+ }
+
+ return total;
+}
+
+
+/*
+ * Read all of the supplied buffer from a file.
+ * This does multiple reads as necessary.
+ * Returns the amount read, or -1 on an error.
+ * A short read is returned on an end of file.
+ */
+int
+fullRead(int fd, char * buf, int len)
+{
+ int cc;
+ int total;
+
+ total = 0;
+
+ while (len > 0)
+ {
+ cc = read(fd, buf, len);
+
+ if (cc < 0)
+ return -1;
+
+ if (cc == 0)
+ break;
+
+ buf += cc;
+ total+= cc;
+ len -= cc;
+ }
+
+ return total;
+}
+
+
+
+#endif
+/* END CODE */
+
+