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[chaz/tar] / src / list.c

/* List a tar archive.
   Copyright (C) 1988, 1992 Free Software Foundation

This file is part of GNU Tar.

GNU Tar 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, or (at your option)
any later version.

GNU Tar 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 GNU Tar; see the file COPYING.  If not, write to
the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.  */

/*
 * List a tar archive.
 *
 * Also includes support routines for reading a tar archive.
 *
 * this version written 26 Aug 1985 by John Gilmore (ihnp4!hoptoad!gnu).
 */

#include <stdio.h>
#include <ctype.h>
#include <sys/types.h>
#include <errno.h>
#ifndef STDC_HEADERS
extern int errno;
#endif
#include <time.h>

#ifdef BSD42
#include <sys/file.h>
#else
#ifndef V7
#include <fcntl.h>
#endif
#endif

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

#include "tar.h"
#include "port.h"

extern FILE *msg_file;

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

union record *head;             /* Points to current archive header */
struct stat hstat;              /* Stat struct corresponding */
int head_standard;              /* Tape header is in ANSI format */

int check_exclude ();
void close_archive ();
void decode_header ();
int findgid ();
int finduid ();
void name_gather ();
int name_match ();
void names_notfound ();
void open_archive ();
void print_header ();
int read_header ();
void saverec ();
void skip_file ();
void skip_extended_headers ();

extern char *quote_copy_string ();


/*
 * Main loop for reading an archive.
 */
void
read_and (do_something)
     void (*do_something) ();
{
  int status = 3;               /* Initial status at start of archive */
  int prev_status;
  extern time_t new_time;
  char save_linkflag;

  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. */

          if (!name_match (current_file_name)
              || (f_new_files && hstat.st_mtime < new_time)
              || (f_exclude && check_exclude (current_file_name)))
            {

              int isextended = 0;

              if (head->header.linkflag == LF_VOLHDR
                  || head->header.linkflag == LF_MULTIVOL
                  || head->header.linkflag == LF_NAMES)
                {
                  (*do_something) ();
                  continue;
                }
              if (f_show_omitted_dirs
                  && head->header.linkflag == LF_DIR)
                msg ("Omitting %s\n", current_file_name);
              /* Skip past it in the archive */
              if (head->header.isextended)
                isextended = 1;
              save_linkflag = head->header.linkflag;
              userec (head);
              if (isextended)
                {
                  /*                                    register union record *exhdr;

                                        for (;;) {
                                            exhdr = findrec();
                                            if (!exhdr->ext_hdr.isextended) {
                                                userec(exhdr);
                                                break;
                                            }
                                        }
                                        userec(exhdr);*/
                  skip_extended_headers ();
                }
              /* Skip to the next header on the archive */
              if (save_linkflag != LF_DIR)
                skip_file ((long) hstat.st_size);
              continue;

            }

          (*do_something) ();
          continue;

          /*
                         * If the previous header was good, tell them
                         * that we are skipping bad ones.
                         */
        case 0:         /* Invalid header */
          userec (head);
          switch (prev_status)
            {
            case 3:             /* Error on first record */
              msg ("Hmm, this doesn't look like a tar archive.");
              /* FALL THRU */
            case 2:             /* Error after record of zeroes */
            case 1:             /* Error after header rec */
              msg ("Skipping to next file header...");
            case 0:             /* Error after error */
              break;
            }
          continue;

        case 2:         /* Record of zeroes */
          userec (head);
          status = prev_status; /* If error after 0's */
          if (f_ignorez)
            continue;
          /* FALL THRU */
        case EOF:               /* End of archive */
          break;
        }
      break;
    };

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


/*
 * Print a header record, based on tar options.
 */
void
list_archive ()
{
  extern char *save_name;
  int isextended = 0;           /* Flag to remember if head is extended */

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

  /* Print the header record */
  if (f_verbose)
    {
      if (f_verbose > 1)
        decode_header (head, &hstat, &head_standard, 0);
      print_header ();
    }

  if (f_gnudump && head->header.linkflag == LF_DUMPDIR)
    {
      size_t size, written, check;
      char *data;
      extern long save_totsize;
      extern long save_sizeleft;

      userec (head);
      if (f_multivol)
        {
          save_name = current_file_name;
          save_totsize = hstat.st_size;
        }
      for (size = hstat.st_size; size > 0; size -= written)
        {
          if (f_multivol)
            save_sizeleft = size;
          data = findrec ()->charptr;
          if (data == NULL)
            {
              msg ("EOF in archive file?");
              break;
            }
          written = endofrecs ()->charptr - data;
          if (written > size)
            written = size;
          errno = 0;
          check = fwrite (data, sizeof (char), written, msg_file);
          userec ((union record *) (data + written - 1));
          if (check != written)
            {
              msg_perror ("only wrote %ld of %ld bytes to file %s", check, written, current_file_name);
              skip_file ((long) (size) - written);
              break;
            }
        }
      if (f_multivol)
        save_name = 0;
      saverec ((union record **) 0);    /* Unsave it */
      fputc ('\n', msg_file);
      fflush (msg_file);
      return;

    }
  saverec ((union record **) 0);/* Unsave it */
  /* Check to see if we have an extended header to skip over also */
  if (head->header.isextended)
    isextended = 1;

  /* Skip past the header in the archive */
  userec (head);

  /*
         * If we needed to skip any extended headers, do so now, by
         * reading extended headers and skipping past them in the
         * archive.
         */
  if (isextended)
    {
      /*                register union record *exhdr;

                for (;;) {
                        exhdr = findrec();

                        if (!exhdr->ext_hdr.isextended) {
                                userec(exhdr);
                                break;
                        }
                        userec(exhdr);
                }*/
      skip_extended_headers ();
    }

  if (f_multivol)
    save_name = current_file_name;
  /* Skip to the next header on the archive */

  skip_file ((long) hstat.st_size);

  if (f_multivol)
    save_name = 0;
}


/*
 * 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 record 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, signed_sum, recsum;
  register char *p;
  register union record *header;
  long from_oct ();
  char **longp;
  char *bp, *data;
  int size, written;
  static char *next_long_name, *next_long_link;
  char *name;

recurse:

  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.
                 */
      signed_sum += *p;
      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];
      signed_sum -= (char) header->header.chksum[i];
    }
  sum += ' ' * sizeof header->header.chksum;
  signed_sum += ' ' * sizeof header->header.chksum;

  if (sum == 8 * ' ')
    {
      /*
                 * This is a zeroed record...whole record is 0's except
                 * for the 8 blanks we faked for the checksum field.
                 */
      return 2;
    }

  if (sum != recsum && signed_sum != recsum)
    return 0;

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

  header->header.arch_name[NAMSIZ - 1] = '\0';
  if (header->header.linkflag == LF_LONGNAME
      || header->header.linkflag == LF_LONGLINK)
    {
      longp = ((header->header.linkflag == LF_LONGNAME)
               ? &next_long_name
               : &next_long_link);

      userec (header);
      if (*longp)
        free (*longp);
      bp = *longp = (char *) ck_malloc (hstat.st_size);

      for (size = hstat.st_size;
           size > 0;
           size -= written)
        {
          data = findrec ()->charptr;
          if (data == NULL)
            {
              msg ("Unexpected EOF on archive file");
              break;
            }
          written = endofrecs ()->charptr - data;
          if (written > size)
            written = size;

          bcopy (data, bp, written);
          bp += written;
          userec ((union record *) (data + written - 1));
        }
      goto recurse;
    }
  else
    {
      name = (next_long_name
              ? next_long_name
              : head->header.arch_name);
      if (current_file_name)
        free (current_file_name);
      current_file_name = malloc (strlen (name) + 1);
      strcpy (current_file_name, name);

      name = (next_long_link
              ? next_long_link
              : head->header.arch_linkname);
      if (current_link_name)
        free (current_link_name);
      current_link_name = malloc (strlen (name) + 1);
      strcpy (current_link_name, name);

      next_long_link = next_long_name = 0;
      return 1;
    }
}


/*
 * 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 should NOT be called twice for the same record, since the
 * two calls might use different "wantug" values and thus might end up with
 * different uid/gid for the two calls.  If anybody wants the uid/gid they
 * should decode it first, and other callers should decode it without uid/gid
 * before calling a routine, e.g. print_header, that assumes decoded data.
 */
void
decode_header (header, st, stdp, wantug)
     register union record *header;
     register struct stat *st;
     int *stdp;
     int wantug;
{
  long from_oct ();
  char **longp;
  char *bp, *data;
  int size, written;

  st->st_mode = from_oct (8, header->header.mode);
  st->st_mtime = from_oct (1 + 12, header->header.mtime);
  if (f_gnudump)
    {
      st->st_atime = from_oct (1 + 12, header->header.atime);
      st->st_ctime = from_oct (1 + 12, header->header.ctime);
    }

  if (0 == strcmp (header->header.magic, TMAGIC))
    {
      /* Unix Standard tar archive */
      *stdp = 1;
      if (wantug)
        {
#ifdef NONAMES
          st->st_uid = from_oct (8, header->header.uid);
          st->st_gid = from_oct (8, header->header.gid);
#else
          st->st_uid =
            (*header->header.uname
             ? finduid (header->header.uname)
             : from_oct (8, header->header.uid));
          st->st_gid =
            (*header->header.gname
             ? findgid (header->header.gname)
             : from_oct (8, header->header.gid));
#endif
        }
#if defined(S_IFBLK) || defined(S_IFCHR)
      switch (header->header.linkflag)
        {
        case LF_BLK:
        case LF_CHR:
          st->st_rdev = 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_rdev = 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.
 *
 * Plain and fancy file header block logging.
 * Non-verbose just prints the name, e.g. for "tar t" or "tar x".
 * This should just contain file names, so it can be fed back into tar
 * with xargs or the "-T" option.  The verbose option can give a bunch
 * of info, one line per file.  I doubt anybody tries to parse its
 * format, or if they do, they shouldn't.  Unix tar is pretty random here
 * anyway.
 *
 * Note that print_header uses the globals <head>, <hstat>, and
 * <head_standard>, which must be set up in advance.  This is not very clean
 * and should be cleaned up.  FIXME.
 */
#define UGSWIDTH        18      /* min width of User, group, size */
/* UGSWIDTH of 18 means that with user and group names <= 8 chars the columns
   never shift during the listing.  */
#define DATEWIDTH       19      /* Last mod date */
static int ugswidth = UGSWIDTH; /* Max width encountered so far */

void
print_header ()
{
  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 */
  time_t longie;                /* To make ctime() call portable */
  int pad;
  char *name;
  extern long baserec;
  static char *longname;
  static char *longlink;
  int bumplongs;

  if (f_sayblock)
    fprintf (msg_file, "rec %10d: ", baserec + (ar_record - ar_block));
  /* annofile(msg_file, (char *)NULL); */

  if (f_verbose <= 1)
    {
      /* Just the fax, mam. */
      char *name;

      name = quote_copy_string (current_file_name);
      if (name == 0)
        name = current_file_name;
      fprintf (msg_file, "%s\n", name);
      if (name != current_file_name)
        free (name);
    }
  else
    {
      /* File type and modes */
      modes[0] = '?';
      switch (head->header.linkflag)
        {
        case LF_VOLHDR:
          modes[0] = 'V';
          break;

        case LF_MULTIVOL:
          modes[0] = 'M';
          break;

        case LF_NAMES:
          modes[0] = 'N';
          break;

        case LF_LONGNAME:
        case LF_LONGLINK:
          msg ("Visible longname error\n");
          break;

        case LF_SPARSE:
        case LF_NORMAL:
        case LF_OLDNORMAL:
        case LF_LINK:
          modes[0] = '-';
          if ('/' == current_file_name[strlen (current_file_name) - 1])
            modes[0] = 'd';
          break;
        case LF_DUMPDIR:
          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] = 'p';
          break;
        case LF_CONTIG:
          modes[0] = 'C';
          break;
        }

      demode ((unsigned) hstat.st_mode, modes + 1);

      /* Timestamp */
      longie = hstat.st_mtime;
      timestamp = ctime (&longie);
      timestamp[16] = '\0';
      timestamp[24] = '\0';

      /* User and group names */
      if (*head->header.uname && head_standard)
        {
          user = head->header.uname;
        }
      else
        {
          user = uform;
          (void) sprintf (uform, "%d",
                          from_oct (8, head->header.uid));
        }
      if (*head->header.gname && head_standard)
        {
          group = head->header.gname;
        }
      else
        {
          group = gform;
          (void) sprintf (gform, "%d",
                          from_oct (8, head->header.gid));
        }

      /* Format the file size or major/minor device numbers */
      switch (head->header.linkflag)
        {
#if defined(S_IFBLK) || defined(S_IFCHR)
        case LF_CHR:
        case LF_BLK:
          (void) sprintf (size, "%d,%d",
                          major (hstat.st_rdev),
                          minor (hstat.st_rdev));
          break;
#endif
        case LF_SPARSE:
          (void) sprintf (size, "%ld",
                          from_oct (1 + 12, head->header.realsize));
          break;
        default:
          (void) sprintf (size, "%ld", (long) hstat.st_size);
        }

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

      name = quote_copy_string (current_file_name);
      if (!name)
        name = current_file_name;
      fprintf (msg_file, "%s %s/%s %*s%s %s %s %s",
               modes,
               user,
               group,
               ugswidth - pad,
               "",
               size,
               timestamp + 4, timestamp + 20,
               name);

      if (name != current_file_name)
        free (name);
      switch (head->header.linkflag)
        {
        case LF_SYMLINK:
          name = quote_copy_string (current_link_name);
          if (!name)
            name = current_link_name;
          fprintf (msg_file, " -> %s\n", name);
          if (name != current_link_name)
            free (name);
          break;

        case LF_LINK:
          name = quote_copy_string (current_link_name);
          if (!name)
            name = current_link_name;
          fprintf (msg_file, " link to %s\n", current_link_name);
          if (name != current_link_name)
            free (name);
          break;

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

        case LF_OLDNORMAL:
        case LF_NORMAL:
        case LF_SPARSE:
        case LF_CHR:
        case LF_BLK:
        case LF_DIR:
        case LF_FIFO:
        case LF_CONTIG:
        case LF_DUMPDIR:
          putc ('\n', msg_file);
          break;

        case LF_VOLHDR:
          fprintf (msg_file, "--Volume Header--\n");
          break;

        case LF_MULTIVOL:
          fprintf (msg_file, "--Continued at byte %ld--\n", from_oct (1 + 12, head->header.offset));
          break;

        case LF_NAMES:
          fprintf (msg_file, "--Mangled file names--\n");
          break;
        }
    }
  fflush (msg_file);
}

/*
 * 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];
  char *name;
  extern long baserec;

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

      if (f_sayblock)
        fprintf (msg_file, "rec %10d: ", baserec + (ar_record - ar_block));
      /* annofile(msg_file, (char *)NULL); */
      name = quote_copy_string (pathname);
      if (!name)
        name = pathname;
      fprintf (msg_file, "%s %*s %.*s\n",
               modes,
               ugswidth + DATEWIDTH,
               "Creating directory:",
               length,
               pathname);
      if (name != pathname)
        free (name);
    }
}


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

  if (f_multivol)
    {
      save_totsize = size;
      save_sizeleft = size;
    }

  while (size > 0)
    {
      x = findrec ();
      if (x == NULL)
        {                       /* Check it... */
          msg ("Unexpected EOF on archive file");
          exit (EX_BADARCH);
        }
      userec (x);
      size -= RECORDSIZE;
      if (f_multivol)
        save_sizeleft -= RECORDSIZE;
    }
}

void
skip_extended_headers ()
{
  register union record *exhdr;

  for (;;)
    {
      exhdr = findrec ();
      if (!exhdr->ext_hdr.isextended)
        {
          userec (exhdr);
          break;
        }
      userec (exhdr);
    }
}

/*
 * Decode the mode string from a stat entry into a 9-char string and a null.
 */
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++;
        }
    }

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