wip forking, added sash source

1 files changed, 1277 insertions, 0 deletions

diff --git a/src/sash/cmd_tar.c b/src/sash/cmd_tar.c
new file mode 100644
index 0000000..5dd5f21
--- /dev/null
+++ b/src/sash/cmd_tar.c
@@ -0,0 +1,1277 @@
+/*
+ * Copyright (c) 2014 by David I. Bell
+ * Permission is granted to use, distribute, or modify this source,
+ * provided that this copyright notice remains intact.
+ *
+ * The "tar" built-in command.
+ * This allows creation, extraction, and listing of tar files.
+ */
+
+#include "sash.h"
+
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <dirent.h>
+#include <errno.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		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	BOOL	readTarFile(int fileCount, const char ** fileTable);
+static	BOOL	readData(const char * cp, int count);
+static	BOOL	createPath(const char * name, int mode);
+static	long	getOctal(const char * cp, int len);
+
+static	BOOL	readHeader(const TarHeader * hp,
+			int fileCount, const 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, const char ** fileTable);
+
+static	void	writeHeader(const char * fileName,
+			const struct stat * statbuf);
+
+static	BOOL	writeTarFile(int fileCount, const char ** fileTable);
+static	void	writeTarBlock(const char * buf, int len);
+static	BOOL	putOctal(char * cp, int len, long value);
+
+
+
+int
+do_tar(int argc, const char ** argv)
+{
+	const char *	options;
+	BOOL		successFlag;
+
+	argc--;
+	argv++;
+
+	if (argc < 2)
+	{
+		fprintf(stderr, "Too few arguments for tar\n");
+
+		return 1;
+	}
+
+	extractFlag = FALSE;
+	createFlag = FALSE;
+	listFlag = FALSE;
+	verboseFlag = FALSE;
+	tarName = NULL;
+	tarDev = 0;
+	tarInode = 0;
+	tarFd = -1;
+
+	/*
+	 * Parse the options.
+	 */
+	options = *argv++;
+	argc--;
+
+	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;
+
+			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;
+	}
+
+	if (tarName == NULL)
+	{
+		fprintf(stderr, "The 'f' flag 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)
+		successFlag = writeTarFile(argc, argv);
+	else
+		successFlag = readTarFile(argc, argv);
+
+	return !successFlag;
+}
+
+
+/*
+ * 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.
+ * Returns TRUE on success.
+ */
+static BOOL
+readTarFile(int fileCount, const char ** fileTable)
+{
+	const char *	cp;
+	BOOL		successFlag;
+	int		cc;
+	int		inCc;
+	int		blockSize;
+	char		buf[BUF_SIZE];
+
+	skipFileFlag = FALSE;
+	badHeader = FALSE;
+	warnedRoot = FALSE;
+	eofFlag = FALSE;
+	inHeader = TRUE;
+	successFlag = TRUE;
+
+	inCc = 0;
+	dataCc = 0;
+	outFd = -1;
+	blockSize = sizeof(buf);
+	cp = buf;
+
+	/*
+	 * Open the tar file for reading.
+	 */
+	tarFd = open(tarName, O_RDONLY);
+
+	if (tarFd < 0)
+	{
+		perror(tarName);
+
+		return FALSE;
+	}
+
+	/*
+	 * 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 (!intFlag && !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);
+				successFlag = FALSE;
+
+				goto done;
+			}
+
+			if (inCc == 0)
+			{
+				fprintf(stderr,
+					"Unexpected end of file from \"%s\"",
+					tarName);
+				successFlag = FALSE;
+
+				goto done;
+			}
+		}
+
+		/*
+		 * If we are expecting a header block then examine it.
+		 */
+		if (inHeader)
+		{
+			if (!readHeader((const TarHeader *) cp, fileCount, fileTable))
+				successFlag = FALSE;
+
+			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;
+
+		if (!readData(cp, cc))
+			successFlag = FALSE;
+
+		/*
+		 * 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;
+	}
+
+	/*
+	 * Check for an interrupt.
+	 */
+	if (intFlag)
+	{
+		fprintf(stderr, "Interrupted - aborting\n");
+		successFlag = FALSE;
+	}
+
+done:
+	/*
+	 * Close the tar file if needed.
+	 */
+	if ((tarFd >= 0) && (close(tarFd) < 0))
+	{
+		perror(tarName);
+		successFlag = FALSE;
+	}
+
+	/*
+	 * Close the output file if needed.
+	 * This is only done here on a previous error and so no
+	 * message is required on errors.
+	 */
+	if (outFd >= 0)
+		(void) close(outFd);
+
+	return successFlag;
+}
+
+
+/*
+ * 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.  Returns TRUE on success.
+ */
+static BOOL
+readHeader(const TarHeader * hp, int fileCount, const char ** fileTable)
+{
+	int		mode;
+	int		uid;
+	int		gid;
+	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 TRUE;
+		}
+
+		eofFlag = TRUE;
+
+		return TRUE;
+	}
+
+	/*
+	 * 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));
+
+	if ((mode < 0) || (uid < 0) || (gid < 0) || (size < 0))
+	{
+		if (!badHeader)
+			fprintf(stderr, "Bad tar header, skipping\n");
+
+		badHeader = TRUE;
+
+		return FALSE;
+	}
+
+	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 TRUE;
+	}
+
+	/*
+	 * 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 TRUE;
+	}
+
+	/*
+	 * 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 FALSE;
+		}
+
+		return TRUE;
+	}
+
+	if (softLink)
+	{
+#ifdef	S_ISLNK
+		if (symlink(hp->linkName, name) < 0)
+		{
+			perror(name);
+
+			return FALSE;
+		}
+
+		return TRUE;
+#else
+		fprintf(stderr, "Cannot create symbolic links\n");
+#endif
+		return FALSE;
+	}
+
+	/*
+	 * If the file is a directory, then just create the path.
+	 */
+	if (S_ISDIR(mode))
+		return createPath(name, mode);
+
+	/*
+	 * There is a file to write.
+	 * First create the path to it if necessary with a default permission.
+	 */
+	if (!createPath(name, 0777))
+		return FALSE;
+
+	inHeader = (size == 0);
+	dataCc = size;
+
+	/*
+	 * Start the output file.
+	 */
+	outFd = open(name, O_WRONLY | O_CREAT | O_TRUNC, mode);
+
+	if (outFd < 0)
+	{
+		perror(name);
+		skipFileFlag = TRUE;
+
+		return FALSE;
+	}
+
+	/*
+	 * If the file is empty, then that's all we need to do.
+	 */
+	if (size == 0)
+	{
+		(void) close(outFd);
+		outFd = -1;
+	}
+
+	return TRUE;
+}
+
+
+/*
+ * Handle a data block of some specified size that was read.
+ * Returns TRUE on success.
+ */
+static BOOL
+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 TRUE;
+
+	/*
+	 * Write the data to the output file.
+	 */
+	if (fullWrite(outFd, cp, count) < 0)
+	{
+		perror(outName);
+		(void) close(outFd);
+		outFd = -1;
+		skipFileFlag = TRUE;
+
+		return FALSE;
+	}
+
+	/*
+	 * If the write failed, close the file and disable further
+	 * writes to this file.
+	 */
+	if (dataCc <= 0)
+	{
+		if (close(outFd))
+			perror(outName);
+
+		outFd = -1;
+
+		return FALSE;
+	}
+
+	return TRUE;
+}
+
+
+/*
+ * Write a tar file containing the specified files.
+ * Returns TRUE on success.
+ */
+static BOOL
+writeTarFile(int fileCount, const char ** fileTable)
+{
+	struct	stat	statbuf;
+	BOOL		successFlag;
+
+	successFlag = TRUE;
+	errorFlag = FALSE;
+
+	/*
+	 * Make sure there is at least one file specified.
+	 */
+	if (fileCount <= 0)
+	{
+		fprintf(stderr, "No files specified to be saved\n");
+
+		return FALSE;
+	}
+
+	/*
+	 * Create the tar file for writing.
+	 */
+	tarFd = open(tarName, O_WRONLY | O_CREAT | O_TRUNC, 0666);
+
+	if (tarFd < 0)
+	{
+		perror(tarName);
+
+		return FALSE;
+	}
+
+	/*
+	 * Get the device and inode of the tar file for checking later.
+	 */
+	if (fstat(tarFd, &statbuf) < 0)
+	{
+		perror(tarName);
+		successFlag = FALSE;
+
+		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 (!intFlag && !errorFlag && (fileCount-- > 0))
+	{
+		saveFile(*fileTable++, FALSE);
+	}
+
+	if (intFlag)
+	{
+		fprintf(stderr, "Interrupted - aborting archiving\n");
+		successFlag = 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 ((tarFd >= 0) && (close(tarFd) < 0))
+	{
+		perror(tarName);
+		successFlag = FALSE;
+	}
+
+	return successFlag;
+}
+
+
+/*
+ * 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 (!intFlag && (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 (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 (!intFlag && !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.
+ * Returns TRUE on success.
+ */
+static BOOL
+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 = '/';
+	}
+
+	return TRUE;
+}
+
+
+/*
+ * 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, const 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;
+}
+
+/* END CODE */