/*
 * List a tar archive.
 *
 * Also includes support routines for reading a tar archive.
 *
 * Pubic Domain version written 26 Aug 1985 by John Gilmore (ihnp4!hoptoad!gnu).
 * MS-DOS port 2/87 by Eric Roskos.
 * Minix  port 3/88 by Eric Roskos.
 *
 * @(#)list.c 1.18 9/23/86 Public Domain - gnu
 */
#include <stdio.h>
#include <ctype.h>
#include <sys/types.h>
#include <sys/stat.h>
#ifndef MSDOS
#ifndef V7
#include <sys/file.h>
#endif /* V7 */
#else							/* ifdef MSDOS */
#include <fcntl.h>
#endif

char           *ctime();		/* From libc.a */

#define	isodigit(c)	( ((c) >= '0') && ((c) <= '7') )

#include "tar.h"

long            from_oct();		/* Decode octal number */
void            demode();		/* Print file mode */

union record   *head;			/* Points to current archive header */
struct stat     hstat[1];		/* Stat struct corresponding */
struct stat    *phstat = hstat;		/* to overcome construct ACK C can't handle */

void            print_header();
void            skip_file();


/*
 * Main loop for reading an archive.
 */
void
read_and(do_something)
void            (*do_something) ();

{
	int             status = 1;
	int             prev_status;
	char           *xname;
	char           *fixname();

	name_gather();				/* Gather all the names */
	open_archive(1);			/* Open for reading */

	for (;;)
	{
		prev_status = status;
		status = read_header();
		switch (status)
		{

		case 1:				/* Valid header */
			/* We should decode next field (mode) first... */
			/* Ensure incoming names are null terminated. */
			head->header.name[NAMSIZ - 1] = '\0';
			/* make a valid filename for this OS */
			xname = fixname(head->header.name);

			if (!name_match(head->header.name))
			{
				/* Skip past it in the archive */
				userec(head);
				/* Skip to the next header on the archive */
				if (head->header.linkflag != LF_BLK &&
				    head->header.linkflag != LF_CHR)
					skip_file((long) phstat->st_size);
				continue;
			}

			(*do_something) (xname);
			continue;

			/*
			 * If the previous header was good, tell them that we are
			 * skipping bad ones. 
			 */
		case 0:				/* Invalid header */
	case0:
			userec(head);
			if (prev_status == 1)
			{
				annorec(stderr, tar);
				fprintf(stderr,
					"Skipping to next file header...\n");
			}
			continue;

		case 2:				/* Block of zeroes */
			if (f_ignorez)
				goto case0;		/* Just skip if asked */
			/* FALL THRU */
		case EOF:				/* End of archive */
			break;
		}
		break;
	};

	close_archive();
	names_notfound();			/* Print names not found */
}


/*
 * Print a header record, based on tar options.
 */
void
list_archive(xname)
char           *xname;
{

	/* Save the record */
	saverec(&head);

	/* Print the header record */
	print_header(xname);

	/* Skip past it in the archive */
	saverec((union record **) 0);		/* Unsave it */
	userec(head);

	/* Skip to the next header on the archive */
	if (head->header.linkflag != LF_BLK &&
	    head->header.linkflag != LF_CHR) /* no skip if special file - JER */
		skip_file((long) phstat->st_size);
}


/*
 * Read a record that's supposed to be a header record.
 * Return its address in "head", and if it is good, the file's
 * size in hstat->st_size.
 *
 * Return 1 for success, 0 if the checksum is bad, EOF on eof,
 * 2 for a block full of zeros (EOF marker).
 *
 * You must always userec(head) to skip past the header which this
 * routine reads.
 */
int
read_header()
{
	register int    i;
	register long   sum, recsum;
	register char  *p;
	register union record *header;

	header = findrec();
	head = header;				/* This is our current header */
	if (NULL == header)
		return EOF;

	recsum = from_oct(8, header->header.chksum);

	sum = 0;
	p = header->charptr;
	for (i = sizeof(*header); --i >= 0;)
	{

		/*
		 * We can't use unsigned char here because of old compilers, e.g. V7. 
		 */
		sum += 0xFF & *p++;
	}

	/* Adjust checksum to count the "chksum" field as blanks. */
	for (i = sizeof(header->header.chksum); --i >= 0;)
		sum -= 0xFF & header->header.chksum[i];
	sum += ' ' * sizeof header->header.chksum;

	if (sum == recsum)
	{

		/*
		 * Good record.  Decode file size and return. 
		 */
		if (header->header.linkflag == LF_LINK)
			phstat->st_size = 0;	/* Links 0 size on tape */
		else
			phstat->st_size = from_oct(1 + 12, header->header.size);
		return 1;
	}

	if (sum == 8 * ' ')
	{

		/*
		 * This is a zeroed block...whole block is 0's except for the 8
		 * blanks we faked for the checksum field. 
		 */
		return 2;
	}

	return 0;
}


/* 
 * Decode things from a file header record into a "struct stat".
 * Also set "*stdp" to !=0 or ==0 depending whether header record is "Unix
 * Standard" tar format or regular old tar format.
 *
 * read_header() has already decoded the checksum and length, so we don't.
 *
 * If wantug != 0, we want the uid/group info decoded from Unix Standard
 * tapes (for extraction).  If == 0, we are just printing anyway, so save time.
 */
decode_header(header, st, stdp, wantug)
register union record *header;
register struct stat *st;
int            *stdp;
int             wantug;
{
	st->st_mode = from_oct(8, header->header.mode);
	st->st_mtime = from_oct(1 + 12, header->header.mtime);

	if (0 == strcmp(header->header.magic, TMAGIC))
	{
		/* Unix Standard tar archive */
		*stdp = 1;
		if (wantug)
		{
#ifndef MSDOS
#ifndef NONAMES	/* if we have names, still support noname tapes - JER */
			if (header->header.uname[0]) /* JER */
				st->st_uid = finduid(header->header.uname);
			else
#endif /* NONAMES */				
				st->st_uid = from_oct(8, header->header.uid);
#ifndef NONAMES
			if (header->header.gname[0]) /* JER */
				st->st_gid = findgid(header->header.gname);
			else
#endif /* NONAMES */				
				st->st_gid = from_oct(8, header->header.gid);
#else /* MSDOS */
			st->st_uid = st->st_gid = 0;		/* unsupported in DOS */
#endif /* MSDOS */
		}
#ifndef MSDOS
		switch (header->header.linkflag)
		case LF_BLK:
		case LF_CHR:
			st->st_dev = makedev(from_oct(8, header->header.devmajor),
				from_oct(8, header->header.devminor));
#endif
	}
	else
	{
		/* Old fashioned tar archive */
		*stdp = 0;
		st->st_uid = from_oct(8, header->header.uid);
		st->st_gid = from_oct(8, header->header.gid);
		st->st_dev = 0;
	}
}


/*
 * Quick and dirty octal conversion.
 *
 * Result is -1 if the field is invalid (all blank, or nonoctal).
 */
long
from_oct(digs, where)
register int    digs;
register char  *where;
{
	register long   value;

	while (isspace(*where))
	{							/* Skip spaces */
		where++;
		if (--digs <= 0)
			return -1;			/* All blank field */
	}
	value = 0;
	while (digs > 0 && isodigit(*where))
	{							/* Scan til nonoctal */
		value = (value << 3) | (*where++ - '0');
		--digs;
	}

	if (digs > 0 && *where && !isspace(*where))
		return -1;				/* Ended on non-space/nul */

	return value;
}


/*
 * Actually print it.
 */
#define	UGSWIDTH	11			/* min width of User, group, size */
#define	DATEWIDTH	19			/* Last mod date */
static int      ugswidth = UGSWIDTH;	/* Max width encountered so far */

void
print_header(xname)
char           *xname;
{
	char            modes[11];
	char           *timestamp;
	char            uform[11], gform[11];		/* These hold formatted ints */
	char           *user, *group;
	char            size[24];	/* Holds a formatted long or maj, min */
	long            longie;		/* To make ctime() call portable */
	int             pad;
	int             header_std;	/* Is header standard or not? */
	register int	i;
#ifdef MSDOS
	char		blanks[26];
#endif

	annofile(stdout, (char *) NULL);

	if (f_verbose)
	{
		decode_header(head, hstat, &header_std, 0);

		/* File type and modes */
		modes[0] = '?';
		switch (head->header.linkflag)
		{
		case LF_NORMAL:
		case LF_OLDNORMAL:
		case LF_LINK:
			modes[0] = '-';
			if ('/' == head->header.name[strlen(head->header.name) - 1])
				modes[0] = 'd';
			break;
		case LF_DIR:
			modes[0] = 'd';
			break;
		case LF_SYMLINK:
			modes[0] = 'l';
			break;
		case LF_BLK:
			modes[0] = 'b';
			break;
		case LF_CHR:
			modes[0] = 'c';
			break;
		case LF_FIFO:
			modes[0] = 'f';
			break;
		case LF_CONTIG:
			modes[0] = '=';
			break;
		}
#ifdef MSDOS
		if (convmode(xname) & O_TEXT)
			modes[0] = 'a';
#endif

		demode((unsigned) phstat->st_mode, modes + 1);

		/* Timestamp */
		longie = phstat->st_mtime;
#ifdef MSDOS
		/* following is due to a bug in MSDOS's ctime() */
		if (longie < 0x10000000L)
		{
			memset(blanks, ' ', sizeof(blanks)-1);
			blanks[sizeof(blanks)-1] = '\0';
			timestamp = blanks;
		}
		else
#endif
			timestamp = ctime(&longie);
		timestamp[16] = '\0';
		timestamp[24] = '\0';

		/* User and group names */
		if (*head->header.uname && header_std)
		{
			user = head->header.uname;
		}
		else
		{
			user = uform;
			(void) sprintf(uform, "%d", (int) phstat->st_uid);
		}
		if (*head->header.gname && header_std)
		{
			group = head->header.gname;
		}
		else
		{
			group = gform;
			(void) sprintf(gform, "%d", (int) phstat->st_gid);
		}

		/* Format the file size or major/minor device numbers */
		switch (head->header.linkflag)
		{
		case LF_CHR:
		case LF_BLK:
#ifdef V7
			(void) sprintf(size, "(%d, %d) %D",
#else
			(void) sprintf(size, "%d, %d",
#endif
				major(phstat->st_dev),
				minor(phstat->st_dev),
				/* size has meaning for Minix - JER */
				(long)phstat->st_size);
			break;

		default:
#ifdef V7
			(void) sprintf(size, "%D", (long) phstat->st_size);
#else
			(void) sprintf(size, "%ld", (long) phstat->st_size);
#endif
		}

		/* Figure out padding and print the whole line. */
		pad = strlen(user) + strlen(group) + strlen(size) + 1;
		if (pad > ugswidth)
			ugswidth = pad;

			printf("%s %s/%s ", modes, user, group);
			for (i = ugswidth - pad; i > 0; i--) putchar(' ');
			printf("%s %s %s %s", size, timestamp+4,
				timestamp+20, head->header.name);
	}
	else
	{
		printf("%s", head->header.name);
	}
	if (strcmp(head->header.name, xname))
		printf(" (%s)", xname);

	if (f_verbose)
		switch (head->header.linkflag)
		{
		case LF_SYMLINK:
			printf(" -> %s\n", head->header.linkname);
			break;

		case LF_LINK:
			printf(" link to %s\n", head->header.linkname);
			break;

		default:
			printf(" unknown file type '%c'\n", head->header.linkflag);
			break;

		case LF_OLDNORMAL:
		case LF_NORMAL:
		case LF_CHR:
		case LF_BLK:
		case LF_DIR:
		case LF_FIFO:
		case LF_CONTIG:
			putc('\n', stdout);
			break;
		}
	else
	{
		putc('\n', stdout);
	}

	/* FIXME: we don't print major/minor device numbers */
}

/*
 * Print a similar line when we make a directory automatically.
 */
void
pr_mkdir(pathname, length, mode)
char           *pathname;
int             length;
int             mode;
{
	char            modes[11];

	if (f_verbose)
	{
		/* File type and modes */
		modes[0] = 'd';
		demode((unsigned) mode, modes + 1);

		annofile(stdout, (char *) NULL);
		printf("%s %*s %.*s\n",
			modes,
			ugswidth + DATEWIDTH,
			"Creating directory:",
			length,
			pathname);
	}
}


/*
 * Skip over <size> bytes of data in records in the archive.
 */
void
skip_file(size)
register long   size;
{
	union record   *x;

	while (size > 0)
	{
		x = findrec();
		if (x == NULL)
		{						/* Check it... */
			annorec(stderr, tar);
			fprintf(stderr, "Unexpected EOF on archive file\n");
			exit(EX_BADARCH);
		}
		userec(x);
		size -= RECORDSIZE;
	}
}


/*
 * Decode the mode string from a stat entry into a 9-char string and a null.
 * This is good, portable coding, John!
 */
void
demode(mode, string)
register unsigned mode;
register char  *string;
{
	register unsigned mask;
	register char  *rwx = "rwxrwxrwx";

	for (mask = 0400; mask != 0; mask >>= 1)
	{
		if (mode & mask)
			*string++ = *rwx++;
		else
		{
			*string++ = '-';
			rwx++;
		}
	}

#ifdef S_ISUID
	if (mode & S_ISUID)
		if (string[-7] == 'x')
			string[-7] = 's';
		else
			string[-7] = 'S';
#endif
#ifdef S_ISGID
	if (mode & S_ISGID)
		if (string[-4] == 'x')
			string[-4] = 's';
		else
			string[-4] = 'S';
#endif
#ifdef S_ISVTX
	if (mode & S_ISVTX)
		if (string[-1] == 'x')
			string[-1] = 't';
		else
			string[-1] = 'T';
#endif
	*string = '\0';
}