/* Read incremental snapshot file (directory file).
If the file has older incremental version, make sure that it is processed
correctly and that tar will use the most conservative backup method among
possible alternatives (i.e. prefer ALL_CHILDREN over CHANGED_CHILDREN,
etc.) This ensures that the snapshots are updated to the recent version
without any loss of data. */
void
read_directory_file (void)
{
int fd;
char *buf = NULL;
size_t bufsize = 0;
int flags = O_RDWR | O_CREAT;
if (incremental_level == 0)
flags |= O_TRUNC;
/* Open the file for both read and write. That way, we can write
it later without having to reopen it, and don't have to worry if
we chdir in the meantime. */
fd = open (listed_incremental_option, flags, MODE_RW);
if (fd < 0)
{
open_error (listed_incremental_option);
return;
}
listed_incremental_stream = fdopen (fd, "r+");
if (! listed_incremental_stream)
{
open_error (listed_incremental_option);
close (fd);
return;
}
/* Consume the first name from the name list and reset the
list afterwards. This is done to change to the new
directory, if the first name is a chdir request (-C dir),
which is necessary to recreate absolute file names. */
name_from_list ();
blank_name_list ();
if (0 < getline (&buf, &bufsize, listed_incremental_stream))
{
char *ebuf;
uintmax_t incremental_version;
if (strncmp (buf, PACKAGE_NAME, sizeof PACKAGE_NAME - 1) == 0)
{
ebuf = buf + sizeof PACKAGE_NAME - 1;
if (*ebuf++ != '-')
ERROR((1, 0, _("Bad incremental file format")));
for (; *ebuf != '-'; ebuf++)
if (!*ebuf)
ERROR((1, 0, _("Bad incremental file format")));
incremental_version = strtoumax (ebuf + 1, NULL, 10);
}
else
incremental_version = 0;
switch (incremental_version)
{
case 0:
case 1:
read_incr_db_01 (incremental_version, buf);
break;
case TAR_INCREMENTAL_VERSION:
read_incr_db_2 ();
break;
default:
ERROR ((1, 0, _("Unsupported incremental format version: %"PRIuMAX),
incremental_version));
}
}
if (ferror (listed_incremental_stream))
read_error (listed_incremental_option);
if (buf)
free (buf);
}
/* Read incremental snapshot file (directory file).
If the file has older incremental version, make sure that it is processed
correctly and that tar will use the most conservative backup method among
possible alternatives (i.e. prefer ALL_CHILDREN over CHANGED_CHILDREN,
etc.) This ensures that the snapshots are updated to the recent version
without any loss of data. */
void
read_directory_file (void)
{
int fd;
char *buf = 0;
size_t bufsize;
/* Open the file for both read and write. That way, we can write
it later without having to reopen it, and don't have to worry if
we chdir in the meantime. */
fd = open (listed_incremental_option, O_RDWR | O_CREAT, MODE_RW);
if (fd < 0)
{
open_error (listed_incremental_option);
return;
}
listed_incremental_stream = fdopen (fd, "r+");
if (! listed_incremental_stream)
{
open_error (listed_incremental_option);
close (fd);
return;
}
if (0 < getline (&buf, &bufsize, listed_incremental_stream))
{
char *ebuf;
uintmax_t incremental_version;
if (strncmp (buf, PACKAGE_NAME, sizeof PACKAGE_NAME - 1) == 0)
{
ebuf = buf + sizeof PACKAGE_NAME - 1;
if (*ebuf++ != '-')
ERROR((1, 0, _("Bad incremental file format")));
for (; *ebuf != '-'; ebuf++)
if (!*ebuf)
ERROR((1, 0, _("Bad incremental file format")));
incremental_version = strtoumax (ebuf + 1, NULL, 10);
}
else
incremental_version = 0;
switch (incremental_version)
{
case 0:
case 1:
read_incr_db_01 (incremental_version, buf);
break;
case TAR_INCREMENTAL_VERSION:
read_incr_db_2 ();
break;
default:
ERROR ((1, 0, _("Unsupported incremental format version: %"PRIuMAX),
incremental_version));
}
}
if (ferror (listed_incremental_stream))
read_error (listed_incremental_option);
if (buf)
free (buf);
}
