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NetBSD/gnu/usr.bin/tar/create.c
hubertf abda8d9447 Allow hardlinks to symlinks. 
Reviewed by: Bill Studenmund, Klaus Klein
1999-09-05 23:34:39 +00:00

1463 lines
33 KiB
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/* Create a tar archive.
Copyright (C) 1985, 1992, 1993 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. */
#ifndef lint
static char rcsid[] = "$Id: create.c,v 1.8 1999/09/05 23:34:40 hubertf Exp $";
#endif /* not lint */
/*
* Create a tar archive.
*
* Written 25 Aug 1985 by John Gilmore, ihnp4!hoptoad!gnu.
*/
#ifdef _AIX
#pragma alloca
#endif
#include <sys/types.h>
#include <stdio.h>
#include <errno.h>
#ifndef STDC_HEADERS
extern int errno;
#endif
#ifdef BSD42
#include <sys/file.h>
#else
#ifndef V7
#include <fcntl.h>
#endif
#endif
#include "tar.h"
#include "port.h"
#ifndef __MSDOS__
#include <pwd.h>
#include <grp.h>
#endif
#if defined (_POSIX_VERSION)
#include <utime.h>
#else
struct utimbuf
{
long actime;
long modtime;
};
#endif
extern struct stat hstat; /* Stat struct corresponding */
#ifndef __MSDOS__
extern dev_t ar_dev;
extern ino_t ar_ino;
#endif
/* JF */
extern struct name *gnu_list_name;
/*
* If there are no symbolic links, there is no lstat(). Use stat().
*/
#ifndef S_ISLNK
#define lstat stat
#endif
extern void print_header ();
union record *start_header ();
void blank_name_list ();
int check_exclude ();
PTR ck_malloc ();
PTR ck_realloc ();
void clear_buffer ();
void close_archive ();
void collect_and_sort_names ();
int confirm ();
int deal_with_sparse ();
void find_new_file_size ();
void finish_header ();
int finish_sparse_file ();
void finduname ();
void findgname ();
int is_dot_or_dotdot ();
void open_archive ();
char *name_next ();
void name_close ();
void to_oct ();
void dump_file ();
void write_dir_file ();
void write_eot ();
void write_long ();
int zero_record ();
/* This code moved from tar.h since create.c is the only file that cares
about 'struct link's. This means that other files might not have to
include sys/types.h any more. */
struct link
{
struct link *next;
dev_t dev;
ino_t ino;
short linkcount;
char name[1];
};
struct link *linklist; /* Points to first link in list */
static nolinks; /* Gets set if we run out of RAM */
/*
* "Scratch" space to store the information about a sparse file before
* writing the info into the header or extended header
*/
/* struct sp_array *sparsearray;*/
/* number of elts storable in the sparsearray */
/*int sparse_array_size = 10;*/
void
create_archive ()
{
register char *p;
char *name_from_list ();
open_archive (0); /* Open for writing */
if (f_gnudump)
{
char *buf = ck_malloc (PATH_MAX);
char *q, *bufp;
collect_and_sort_names ();
while (p = name_from_list ())
dump_file (p, -1, 1);
/* if(!f_dironly) { */
blank_name_list ();
while (p = name_from_list ())
{
strcpy (buf, p);
if (p[strlen (p) - 1] != '/')
strcat (buf, "/");
bufp = buf + strlen (buf);
for (q = gnu_list_name->dir_contents; q && *q; q += strlen (q) + 1)
{
if (*q == 'Y')
{
strcpy (bufp, q + 1);
dump_file (buf, -1, 1);
}
}
}
/* } */
free (buf);
}
else
{
while (p = name_next (1))
dump_file (p, -1, 1);
}
write_eot ();
close_archive ();
if (f_gnudump)
write_dir_file ();
name_close ();
}
/*
* Dump a single file. If it's a directory, recurse.
* Result is 1 for success, 0 for failure.
* Sets global "hstat" to stat() output for this file.
*/
void
dump_file (p, curdev, toplevel)
char *p; /* File name to dump */
int curdev; /* Device our parent dir was on */
int toplevel; /* Whether we are a toplevel call */
{
union record *header;
char type;
extern char *save_name; /* JF for multi-volume support */
extern long save_totsize;
extern long save_sizeleft;
union record *exhdr;
char save_linkflag;
extern time_t new_time;
int critical_error = 0;
struct utimbuf restore_times;
/* int sparse_ind = 0;*/
if (f_confirm && !confirm ("add", p))
return;
/*
* Use stat if following (rather than dumping) 4.2BSD's
* symbolic links. Otherwise, use lstat (which, on non-4.2
* systems, is #define'd to stat anyway.
*/
#ifdef STX_HIDDEN /* AIX */
if (0 != f_follow_links ?
statx (p, &hstat, STATSIZE, STX_HIDDEN) :
statx (p, &hstat, STATSIZE, STX_HIDDEN | STX_LINK))
#else
if (0 != f_follow_links ? stat (p, &hstat) : lstat (p, &hstat))
#endif
{
badperror:
msg_perror ("can't add file %s", p);
badfile:
if (!f_ignore_failed_read || critical_error)
errors++;
return;
}
restore_times.actime = hstat.st_atime;
restore_times.modtime = hstat.st_mtime;
#ifdef S_ISHIDDEN
if (S_ISHIDDEN (hstat.st_mode))
{
char *new = (char *) alloca (strlen (p) + 2);
if (new)
{
strcpy (new, p);
strcat (new, "@");
p = new;
}
}
#endif
/* See if we only want new files, and check if this one is too old to
put in the archive. */
if (f_new_files
&& !f_gnudump
&& new_time > hstat.st_mtime
&& !S_ISDIR (hstat.st_mode)
&& (f_new_files > 1 || new_time > hstat.st_ctime))
{
if (curdev == -1)
{
msg ("%s: is unchanged; not dumped", p);
}
return;
}
#ifndef __MSDOS__
/* See if we are trying to dump the archive */
if (ar_dev && hstat.st_dev == ar_dev && hstat.st_ino == ar_ino)
{
msg ("%s is the archive; not dumped", p);
return;
}
#endif
/*
* Check for multiple links.
*
* We maintain a list of all such files that we've written so
* far. Any time we see another, we check the list and
* avoid dumping the data again if we've done it once already.
*/
if (hstat.st_nlink > 1
&& (S_ISREG (hstat.st_mode)
#ifdef S_ISCTG
|| S_ISCTG (hstat.st_mode)
#endif
#ifdef S_ISCHR
|| S_ISCHR (hstat.st_mode)
#endif
#ifdef S_ISBLK
|| S_ISBLK (hstat.st_mode)
#endif
#ifdef S_ISFIFO
|| S_ISFIFO (hstat.st_mode)
#endif
#ifdef S_ISLNK
|| S_ISLNK (hstat.st_mode)
#endif
))
{
register struct link *lp;
/* First quick and dirty. Hashing, etc later FIXME */
for (lp = linklist; lp; lp = lp->next)
{
if (lp->ino == hstat.st_ino &&
lp->dev == hstat.st_dev)
{
char *link_name = lp->name;
/* We found a link. */
while (!f_absolute_paths && *link_name == '/')
{
static int link_warn = 0;
if (!link_warn)
{
msg ("Removing leading / from absolute links");
link_warn++;
}
link_name++;
}
if (link_name - lp->name >= NAMSIZ)
write_long (link_name, LF_LONGLINK);
current_link_name = link_name;
hstat.st_size = 0;
header = start_header (p, &hstat);
if (header == NULL)
{
critical_error = 1;
goto badfile;
}
strncpy (header->header.arch_linkname,
link_name, NAMSIZ);
/* Force null truncated */
header->header.arch_linkname[NAMSIZ - 1] = 0;
header->header.linkflag = LF_LINK;
finish_header (header);
/* FIXME: Maybe remove from list after all links found? */
if (f_remove_files)
{
if (unlink (p) == -1)
msg_perror ("cannot remove %s", p);
}
return; /* We dumped it */
}
}
/* Not found. Add it to the list of possible links. */
lp = (struct link *) ck_malloc ((unsigned) (sizeof (struct link) + strlen (p)));
if (!lp)
{
if (!nolinks)
{
msg (
"no memory for links, they will be dumped as separate files");
nolinks++;
}
}
lp->ino = hstat.st_ino;
lp->dev = hstat.st_dev;
strcpy (lp->name, p);
lp->next = linklist;
linklist = lp;
}
/*
* This is not a link to a previously dumped file, so dump it.
*/
if (S_ISREG (hstat.st_mode)
#ifdef S_ISCTG
|| S_ISCTG (hstat.st_mode)
#endif
)
{
int f; /* File descriptor */
long bufsize, count;
long sizeleft;
register union record *start;
int header_moved;
char isextended = 0;
int upperbound;
/* int end_nulls = 0; */
header_moved = 0;
#if defined(BSD42) || defined(ENABLE_SPARSE)
if (f_sparse_files)
{
/*
* JK - This is the test for sparseness: whether the
* "size" of the file matches the number of blocks
* allocated for it. If there is a smaller number
* of blocks that would be necessary to accommodate
* a file of this size, we have a sparse file, i.e.,
* at least one of those records in the file is just
* a useless hole.
*/
#ifdef hpux /* Nice of HPUX to gratuitiously change it, huh? - mib */
if (hstat.st_size - (hstat.st_blocks * 1024) > 1024)
#else
if (hstat.st_size - (hstat.st_blocks * RECORDSIZE) > RECORDSIZE)
#endif
{
int filesize = hstat.st_size;
register int i;
header = start_header (p, &hstat);
if (header == NULL)
{
critical_error = 1;
goto badfile;
}
header->header.linkflag = LF_SPARSE;
header_moved++;
/*
* Call the routine that figures out the
* layout of the sparse file in question.
* UPPERBOUND is the index of the last
* element of the "sparsearray," i.e.,
* the number of elements it needed to
* describe the file.
*/
upperbound = deal_with_sparse (p, header);
/*
* See if we'll need an extended header
* later
*/
if (upperbound > SPARSE_IN_HDR - 1)
header->header.isextended++;
/*
* We store the "real" file size so
* we can show that in case someone wants
* to list the archive, i.e., tar tvf <file>.
* It might be kind of disconcerting if the
* shrunken file size was the one that showed
* up.
*/
to_oct ((long) hstat.st_size, 1 + 12,
header->header.realsize);
/*
* This will be the new "size" of the
* file, i.e., the size of the file
* minus the records of holes that we're
* skipping over.
*/
find_new_file_size (&filesize, upperbound);
hstat.st_size = filesize;
to_oct ((long) filesize, 1 + 12,
header->header.size);
/* to_oct((long) end_nulls, 1+12,
header->header.ending_blanks);*/
for (i = 0; i < SPARSE_IN_HDR; i++)
{
if (!sparsearray[i].numbytes)
break;
to_oct (sparsearray[i].offset, 1 + 12,
header->header.sp[i].offset);
to_oct (sparsearray[i].numbytes, 1 + 12,
header->header.sp[i].numbytes);
}
}
}
#else
upperbound = SPARSE_IN_HDR - 1;
#endif
sizeleft = hstat.st_size;
/* Don't bother opening empty, world readable files. */
if (sizeleft > 0 || 0444 != (0444 & hstat.st_mode))
{
f = open (p, O_RDONLY | O_BINARY);
if (f < 0)
goto badperror;
}
else
{
f = -1;
}
/* If the file is sparse, we've already taken care of this */
if (!header_moved)
{
header = start_header (p, &hstat);
if (header == NULL)
{
if (f >= 0)
(void) close (f);
critical_error = 1;
goto badfile;
}
}
#ifdef S_ISCTG
/* Mark contiguous files, if we support them */
if (f_standard && S_ISCTG (hstat.st_mode))
{
header->header.linkflag = LF_CONTIG;
}
#endif
isextended = header->header.isextended;
save_linkflag = header->header.linkflag;
finish_header (header);
if (isextended)
{
/* int sum = 0;*/
register int i;
/* register union record *exhdr;*/
/* int arraybound = SPARSE_EXT_HDR;*/
/* static */ int index_offset = SPARSE_IN_HDR;
extend:exhdr = findrec ();
if (exhdr == NULL)
{
critical_error = 1;
goto badfile;
}
bzero (exhdr->charptr, RECORDSIZE);
for (i = 0; i < SPARSE_EXT_HDR; i++)
{
if (i + index_offset > upperbound)
break;
to_oct ((long) sparsearray[i + index_offset].numbytes,
1 + 12,
exhdr->ext_hdr.sp[i].numbytes);
to_oct ((long) sparsearray[i + index_offset].offset,
1 + 12,
exhdr->ext_hdr.sp[i].offset);
}
userec (exhdr);
/* sum += i;
if (sum < upperbound)
goto extend;*/
if (index_offset + i <= upperbound)
{
index_offset += i;
exhdr->ext_hdr.isextended++;
goto extend;
}
}
if (save_linkflag == LF_SPARSE)
{
if (finish_sparse_file (f, &sizeleft, hstat.st_size, p))
goto padit;
}
else
while (sizeleft > 0)
{
if (f_multivol)
{
save_name = p;
save_sizeleft = sizeleft;
save_totsize = hstat.st_size;
}
start = findrec ();
bufsize = endofrecs ()->charptr - start->charptr;
if (sizeleft < bufsize)
{
/* Last read -- zero out area beyond */
bufsize = (int) sizeleft;
count = bufsize % RECORDSIZE;
if (count)
bzero (start->charptr + sizeleft,
(int) (RECORDSIZE - count));
}
count = read (f, start->charptr, bufsize);
if (count < 0)
{
msg_perror ("read error at byte %ld, reading\
%qd bytes, in file %s", hstat.st_size - sizeleft, bufsize, p);
goto padit;
}
sizeleft -= count;
/* This is nonportable (the type of userec's arg). */
userec (start + (count - 1) / RECORDSIZE);
if (count == bufsize)
continue;
msg ("file %s shrunk by %d bytes, padding with zeros.", p, sizeleft);
goto padit; /* Short read */
}
if (f_multivol)
save_name = 0;
if (f >= 0)
(void) close (f);
if (f_remove_files)
{
if (unlink (p) == -1)
msg_perror ("cannot remove %s", p);
}
if (f_atime_preserve)
utime (p, &restore_times);
return;
/*
* File shrunk or gave error, pad out tape to match
* the size we specified in the header.
*/
padit:
while (sizeleft > 0)
{
save_sizeleft = sizeleft;
start = findrec ();
bzero (start->charptr, RECORDSIZE);
userec (start);
sizeleft -= RECORDSIZE;
}
if (f_multivol)
save_name = 0;
if (f >= 0)
(void) close (f);
if (f_atime_preserve)
utime (p, &restore_times);
return;
}
#ifdef S_ISLNK
else if (S_ISLNK (hstat.st_mode))
{
int size;
char *buf = alloca (PATH_MAX + 1);
size = readlink (p, buf, PATH_MAX + 1);
if (size < 0)
goto badperror;
buf[size] = '\0';
if (size >= NAMSIZ)
write_long (buf, LF_LONGLINK);
current_link_name = buf;
hstat.st_size = 0; /* Force 0 size on symlink */
header = start_header (p, &hstat);
if (header == NULL)
{
critical_error = 1;
goto badfile;
}
strncpy (header->header.arch_linkname, buf, NAMSIZ);
header->header.arch_linkname[NAMSIZ - 1] = '\0';
header->header.linkflag = LF_SYMLINK;
finish_header (header); /* Nothing more to do to it */
if (f_remove_files)
{
if (unlink (p) == -1)
msg_perror ("cannot remove %s", p);
}
return;
}
#endif
else if (S_ISDIR (hstat.st_mode))
{
register DIR *dirp;
register struct dirent *d;
char *namebuf;
int buflen;
register int len;
int our_device = hstat.st_dev;
/* Build new prototype name */
len = strlen (p);
buflen = len + NAMSIZ;
namebuf = ck_malloc (buflen + 1);
strncpy (namebuf, p, buflen);
while (len >= 1 && '/' == namebuf[len - 1])
len--; /* Delete trailing slashes */
namebuf[len++] = '/'; /* Now add exactly one back */
namebuf[len] = '\0'; /* Make sure null-terminated */
/*
* Output directory header record with permissions
* FIXME, do this AFTER files, to avoid R/O dir problems?
* If old archive format, don't write record at all.
*/
if (!f_oldarch)
{
hstat.st_size = 0; /* Force 0 size on dir */
/*
* If people could really read standard archives,
* this should be: (FIXME)
header = start_header(f_standard? p: namebuf, &hstat);
* but since they'd interpret LF_DIR records as
* regular files, we'd better put the / on the name.
*/
header = start_header (namebuf, &hstat);
if (header == NULL)
{
critical_error = 1;
goto badfile; /* eg name too long */
}
if (f_gnudump)
header->header.linkflag = LF_DUMPDIR;
else if (f_standard)
header->header.linkflag = LF_DIR;
/* If we're gnudumping, we aren't done yet so don't close it. */
if (!f_gnudump)
finish_header (header); /* Done with directory header */
}
if (f_gnudump)
{
int sizeleft;
int totsize;
int bufsize;
union record *start;
int count;
char *buf, *p_buf;
buf = gnu_list_name->dir_contents; /* FOO */
totsize = 0;
for (p_buf = buf; p_buf && *p_buf;)
{
int tmp;
tmp = strlen (p_buf) + 1;
totsize += tmp;
p_buf += tmp;
}
totsize++;
to_oct ((long) totsize, 1 + 12, header->header.size);
finish_header (header);
p_buf = buf;
sizeleft = totsize;
while (sizeleft > 0)
{
if (f_multivol)
{
save_name = p;
save_sizeleft = sizeleft;
save_totsize = totsize;
}
start = findrec ();
bufsize = endofrecs ()->charptr - start->charptr;
if (sizeleft < bufsize)
{
bufsize = sizeleft;
count = bufsize % RECORDSIZE;
if (count)
bzero (start->charptr + sizeleft, RECORDSIZE - count);
}
bcopy (p_buf, start->charptr, bufsize);
sizeleft -= bufsize;
p_buf += bufsize;
userec (start + (bufsize - 1) / RECORDSIZE);
}
if (f_multivol)
save_name = 0;
if (f_atime_preserve)
utime (p, &restore_times);
return;
}
/* Now output all the files in the directory */
#if 0
if (f_dironly)
return; /* Unless the cmdline said not to */
#endif
/*
* See if we are crossing from one file system to another,
* and avoid doing so if the user only wants to dump one file system.
*/
if (f_local_filesys && !toplevel && curdev != hstat.st_dev)
{
if (f_verbose)
msg ("%s: is on a different filesystem; not dumped", p);
return;
}
errno = 0;
dirp = opendir (p);
if (!dirp)
{
if (errno)
{
msg_perror ("can't open directory %s", p);
}
else
{
msg ("error opening directory %s",
p);
}
return;
}
/* Hack to remove "./" from the front of all the file names */
if (len == 2 && namebuf[0] == '.' && namebuf[1] == '/')
len = 0;
/* Should speed this up by cd-ing into the dir, FIXME */
while (NULL != (d = readdir (dirp)))
{
/* Skip . and .. */
if (is_dot_or_dotdot (d->d_name))
continue;
if (NLENGTH (d) + len >= buflen)
{
buflen = len + NLENGTH (d);
namebuf = ck_realloc (namebuf, buflen + 1);
/* namebuf[len]='\0';
msg("file name %s%s too long",
namebuf, d->d_name);
continue; */
}
strcpy (namebuf + len, d->d_name);
if (f_exclude && check_exclude (namebuf))
continue;
if (!f_norecurse)
dump_file (namebuf, our_device, 0);
}
closedir (dirp);
free (namebuf);
if (f_atime_preserve)
utime (p, &restore_times);
return;
}
#ifdef S_ISCHR
else if (S_ISCHR (hstat.st_mode))
{
type = LF_CHR;
}
#endif
#ifdef S_ISBLK
else if (S_ISBLK (hstat.st_mode))
{
type = LF_BLK;
}
#endif
/* Avoid screwy apollo lossage where S_IFIFO == S_IFSOCK */
#if (_ISP__M68K == 0) && (_ISP__A88K == 0) && defined(S_ISFIFO)
else if (S_ISFIFO (hstat.st_mode))
{
type = LF_FIFO;
}
#endif
#ifdef S_ISSOCK
else if (S_ISSOCK (hstat.st_mode))
{
type = LF_FIFO;
}
#endif
else
goto unknown;
if (!f_standard)
goto unknown;
hstat.st_size = 0; /* Force 0 size */
header = start_header (p, &hstat);
if (header == NULL)
{
critical_error = 1;
goto badfile; /* eg name too long */
}
header->header.linkflag = type;
#if defined(S_IFBLK) || defined(S_IFCHR)
if (type != LF_FIFO)
{
to_oct ((long) major (hstat.st_rdev), 8,
header->header.devmajor);
to_oct ((long) minor (hstat.st_rdev), 8,
header->header.devminor);
}
#endif
finish_header (header);
if (f_remove_files)
{
if (unlink (p) == -1)
msg_perror ("cannot remove %s", p);
}
return;
unknown:
msg ("%s: Unknown file type; file ignored.", p);
}
int
finish_sparse_file (fd, sizeleft, fullsize, name)
int fd;
long *sizeleft, fullsize;
char *name;
{
union record *start;
char tempbuf[RECORDSIZE];
int bufsize, sparse_ind = 0, count;
long pos;
long nwritten = 0;
while (*sizeleft > 0)
{
start = findrec ();
bzero (start->charptr, RECORDSIZE);
bufsize = sparsearray[sparse_ind].numbytes;
if (!bufsize)
{ /* we blew it, maybe */
msg ("Wrote %ld of %ld bytes to file %s",
fullsize - *sizeleft, fullsize, name);
break;
}
pos = lseek (fd, sparsearray[sparse_ind++].offset, 0);
/*
* If the number of bytes to be written here exceeds
* the size of the temporary buffer, do it in steps.
*/
while (bufsize > RECORDSIZE)
{
/* if (amt_read) {
count = read(fd, start->charptr+amt_read, RECORDSIZE-amt_read);
bufsize -= RECORDSIZE - amt_read;
amt_read = 0;
userec(start);
start = findrec();
bzero(start->charptr, RECORDSIZE);
}*/
/* store the data */
count = read (fd, start->charptr, RECORDSIZE);
if (count < 0)
{
msg_perror ("read error at byte %ld, reading %d bytes, in file %s",
fullsize - *sizeleft, bufsize, name);
return 1;
}
bufsize -= count;
*sizeleft -= count;
userec (start);
nwritten += RECORDSIZE; /* XXX */
start = findrec ();
bzero (start->charptr, RECORDSIZE);
}
clear_buffer (tempbuf);
count = read (fd, tempbuf, bufsize);
bcopy (tempbuf, start->charptr, RECORDSIZE);
if (count < 0)
{
msg_perror ("read error at byte %ld, reading %d bytes, in file %s",
fullsize - *sizeleft, bufsize, name);
return 1;
}
/* if (amt_read >= RECORDSIZE) {
amt_read = 0;
userec(start+(count-1)/RECORDSIZE);
if (count != bufsize) {
msg("file %s shrunk by %d bytes, padding with zeros.", name, sizeleft);
return 1;
}
start = findrec();
} else
amt_read += bufsize;*/
nwritten += count; /* XXX */
*sizeleft -= count;
userec (start);
}
free (sparsearray);
/* printf ("Amount actually written is (I hope) %d.\n", nwritten); */
/* userec(start+(count-1)/RECORDSIZE);*/
return 0;
}
void
init_sparsearray ()
{
register int i;
sp_array_size = 10;
/*
* Make room for our scratch space -- initially is 10 elts long
*/
sparsearray = (struct sp_array *) ck_malloc (sp_array_size * sizeof (struct sp_array));
for (i = 0; i < sp_array_size; i++)
{
sparsearray[i].offset = 0;
sparsearray[i].numbytes = 0;
}
}
/*
* Okay, we've got a sparse file on our hands -- now, what we need to do is
* make a pass through the file and carefully note where any data is, i.e.,
* we want to find how far into the file each instance of data is, and how
* many bytes are there. We store this information in the sparsearray,
* which will later be translated into header information. For now, we use
* the sparsearray as convenient storage.
*
* As a side note, this routine is a mess. If I could have found a cleaner
* way to do it, I would have. If anyone wants to find a nicer way to do
* this, feel free.
*/
/* There is little point in trimming small amounts of null data at the */
/* head and tail of blocks -- it's ok if we only avoid dumping blocks */
/* of complete null data */
int
deal_with_sparse (name, header, nulls_at_end)
char *name;
union record *header;
int nulls_at_end;
{
long numbytes = 0;
long offset = 0;
/* long save_offset;*/
int fd;
/* int current_size = hstat.st_size;*/
int sparse_ind = 0, cc;
char buf[RECORDSIZE];
#if 0
int read_last_data = 0; /* did we just read the last record? */
#endif
int amidst_data = 0;
header->header.isextended = 0;
/*
* Can't open the file -- this problem will be caught later on,
* so just return.
*/
if ((fd = open (name, O_RDONLY)) < 0)
return 0;
init_sparsearray ();
clear_buffer (buf);
while ((cc = read (fd, buf, sizeof buf)) != 0)
{
if (sparse_ind > sp_array_size - 1)
{
/*
* realloc the scratch area, since we've run out of room --
*/
sparsearray = (struct sp_array *)
ck_realloc (sparsearray,
2 * sp_array_size * (sizeof (struct sp_array)));
sp_array_size *= 2;
}
if (cc == sizeof buf)
{
if (zero_record (buf))
{
if (amidst_data)
{
sparsearray[sparse_ind++].numbytes
= numbytes;
amidst_data = 0;
}
}
else
{ /* !zero_record(buf) */
if (amidst_data)
numbytes += cc;
else
{
amidst_data = 1;
numbytes = cc;
sparsearray[sparse_ind].offset
= offset;
}
}
}
else if (cc < sizeof buf)
{
/* This has to be the last bit of the file, so this */
/* is somewhat shorter than the above. */
if (!zero_record (buf))
{
if (!amidst_data)
{
amidst_data = 1;
numbytes = cc;
sparsearray[sparse_ind].offset
= offset;
}
else
numbytes += cc;
}
}
offset += cc;
clear_buffer (buf);
}
if (amidst_data)
sparsearray[sparse_ind++].numbytes = numbytes;
else
{
sparsearray[sparse_ind].offset = offset-1;
sparsearray[sparse_ind++].numbytes = 1;
}
close (fd);
return sparse_ind - 1;
}
/*
* Just zeroes out the buffer so we don't confuse ourselves with leftover
* data.
*/
void
clear_buffer (buf)
char *buf;
{
register int i;
for (i = 0; i < RECORDSIZE; i++)
buf[i] = '\0';
}
#if 0 /* I'm leaving this as a monument to Joy Kendall, who wrote it -mib */
/*
* JK -
* This routine takes a character array, and tells where within that array
* the data can be found. It skips over any zeros, and sets the first
* non-zero point in the array to be the "start", and continues until it
* finds non-data again, which is marked as the "end." This routine is
* mainly for 1) seeing how far into a file we must lseek to data, given
* that we have a sparse file, and 2) determining the "real size" of the
* file, i.e., the number of bytes in the sparse file that are data, as
* opposed to the zeros we are trying to skip.
*/
where_is_data (from, to, buffer)
int *from, *to;
char *buffer;
{
register int i = 0;
register int save_to = *to;
int amidst_data = 0;
while (!buffer[i])
i++;
*from = i;
if (*from < 16) /* don't bother */
*from = 0;
/* keep going to make sure there isn't more real
data in this record */
while (i < RECORDSIZE)
{
if (!buffer[i])
{
if (amidst_data)
{
save_to = i;
amidst_data = 0;
}
i++;
}
else if (buffer[i])
{
if (!amidst_data)
amidst_data = 1;
i++;
}
}
if (i == RECORDSIZE)
*to = i;
else
*to = save_to;
}
#endif
/* Note that this routine is only called if zero_record returned true */
#if 0 /* But we actually don't need it at all. */
where_is_data (from, to, buffer)
int *from, *to;
char *buffer;
{
char *fp, *tp;
for (fp = buffer; !*fp; fp++)
;
for (tp = buffer + RECORDSIZE - 1; !*tp; tp--)
;
*from = fp - buffer;
*to = tp - buffer + 1;
}
#endif
/*
* Takes a recordful of data and basically cruises through it to see if
* it's made *entirely* of zeros, returning a 0 the instant it finds
* something that is a non-zero, i.e., useful data.
*/
int
zero_record (buffer)
char *buffer;
{
register int i;
for (i = 0; i < RECORDSIZE; i++)
if (buffer[i] != '\000')
return 0;
return 1;
}
void
find_new_file_size (filesize, highest_index)
int *filesize;
int highest_index;
{
register int i;
*filesize = 0;
for (i = 0; sparsearray[i].numbytes && i <= highest_index; i++)
*filesize += sparsearray[i].numbytes;
}
/*
* Make a header block for the file name whose stat info is st .
* Return header pointer for success, NULL if the name is too long.
*/
union record *
start_header (name, st)
char *name;
register struct stat *st;
{
register union record *header;
if (strlen (name) >= NAMSIZ)
write_long (name, LF_LONGNAME);
header = (union record *) findrec ();
bzero (header->charptr, sizeof (*header)); /* XXX speed up */
/*
* Check the file name and put it in the record.
*/
if (!f_absolute_paths)
{
static int warned_once = 0;
#ifdef __MSDOS__
if (name[1] == ':')
{
name += 2;
if (!warned_once++)
msg ("Removing drive spec from names in the archive");
}
#endif
while ('/' == *name)
{
name++; /* Force relative path */
if (!warned_once++)
msg ("Removing leading / from absolute path names in the archive.");
}
}
current_file_name = name;
strncpy (header->header.arch_name, name, NAMSIZ);
header->header.arch_name[NAMSIZ - 1] = '\0';
to_oct ((long) (f_oldarch ? (st->st_mode & 07777) : st->st_mode),
8, header->header.mode);
to_oct ((long) st->st_uid, 8, header->header.uid);
to_oct ((long) st->st_gid, 8, header->header.gid);
to_oct ((long) st->st_size, 1 + 12, header->header.size);
to_oct ((long) st->st_mtime, 1 + 12, header->header.mtime);
/* header->header.linkflag is left as null */
if (f_gnudump)
{
to_oct ((long) st->st_atime, 1 + 12, header->header.atime);
to_oct ((long) st->st_ctime, 1 + 12, header->header.ctime);
}
#ifndef NONAMES
/* Fill in new Unix Standard fields if desired. */
if (f_standard)
{
header->header.linkflag = LF_NORMAL; /* New default */
strcpy (header->header.magic, TMAGIC); /* Mark as Unix Std */
finduname (header->header.uname, st->st_uid);
findgname (header->header.gname, st->st_gid);
}
#endif
return header;
}
/*
* Finish off a filled-in header block and write it out.
* We also print the file name and/or full info if verbose is on.
*/
void
finish_header (header)
register union record *header;
{
register int i, sum;
register char *p;
bcopy (CHKBLANKS, header->header.chksum, sizeof (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++;
}
/*
* Fill in the checksum field. It's formatted differently
* from the other fields: it has [6] digits, a null, then a
* space -- rather than digits, a space, then a null.
* We use to_oct then write the null in over to_oct's space.
* The final space is already there, from checksumming, and
* to_oct doesn't modify it.
*
* This is a fast way to do:
* (void) sprintf(header->header.chksum, "%6o", sum);
*/
to_oct ((long) sum, 8, header->header.chksum);
header->header.chksum[6] = '\0'; /* Zap the space */
userec (header);
if (f_verbose)
{
extern union record *head;/* Points to current tape header */
extern int head_standard; /* Tape header is in ANSI format */
/* These globals are parameters to print_header, sigh */
head = header;
/* hstat is already set up */
head_standard = f_standard;
print_header ();
}
return;
}
/*
* Quick and dirty octal conversion.
* Converts long "value" into a "digs"-digit field at "where",
* including a trailing space and room for a null. "digs"==3 means
* 1 digit, a space, and room for a null.
*
* We assume the trailing null is already there and don't fill it in.
* This fact is used by start_header and finish_header, so don't change it!
*
* This should be equivalent to:
* (void) sprintf(where, "%*lo ", digs-2, value);
* except that sprintf fills in the trailing null and we don't.
*/
void
to_oct (value, digs, where)
register long value;
register int digs;
register char *where;
{
--digs; /* Trailing null slot is left alone */
where[--digs] = ' '; /* Put in the space, though */
/* Produce the digits -- at least one */
do
{
where[--digs] = '0' + (char) (value & 7); /* one octal digit */
value >>= 3;
}
while (digs > 0 && value != 0);
/* Leading spaces, if necessary */
while (digs > 0)
where[--digs] = ' ';
}
/*
* Write the EOT record(s).
* We actually zero at least one record, through the end of the block.
* Old tar writes garbage after two zeroed records -- and PDtar used to.
*/
void
write_eot ()
{
union record *p;
int bufsize;
p = findrec ();
if (p)
{
bufsize = endofrecs ()->charptr - p->charptr;
bzero (p->charptr, bufsize);
userec (p);
}
}
/* Write a LF_LONGLINK or LF_LONGNAME record. */
void
write_long (p, type)
char *p;
char type;
{
int size = strlen (p) + 1;
int bufsize;
union record *header;
struct stat foo;
bzero (&foo, sizeof foo);
foo.st_size = size;
header = start_header ("././@LongLink", &foo);
header->header.linkflag = type;
finish_header (header);
header = findrec ();
bufsize = endofrecs ()->charptr - header->charptr;
while (bufsize < size)
{
bcopy (p, header->charptr, bufsize);
p += bufsize;
size -= bufsize;
userec (header + (bufsize - 1) / RECORDSIZE);
header = findrec ();
bufsize = endofrecs ()->charptr - header->charptr;
}
bcopy (p, header->charptr, size);
bzero (header->charptr + size, bufsize - size);
userec (header + (size - 1) / RECORDSIZE);
}
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