struct
archive
*
archive_read_new(
void
)
int
archive_read_support_compression_all(
struct archive *
)
int
archive_read_support_compression_bzip2(
struct archive *
)
int
archive_read_support_compression_compress(
struct archive *
)
int
archive_read_support_compression_gzip(
struct archive *
)
int
archive_read_support_compression_none(
struct archive *
)
int
archive_read_support_compression_program(
struct archive *
const char *cmd
)
int
archive_read_support_format_all(
struct archive *
)
int
archive_read_support_format_cpio(
struct archive *
)
int
archive_read_support_format_empty(
struct archive *
)
int
archive_read_support_format_iso9660(
struct archive *
)
int
archive_read_support_format_tar(
struct archive *
)
int
archive_read_support_format_zip(
struct archive *
)
int
archive_read_open(
struct archive *
void *client_data
archive_open_callback *
archive_read_callback *
archive_close_callback *
)
int
archive_read_open2(
struct archive *
void *client_data
archive_open_callback *
archive_read_callback *
archive_skip_callback *
archive_close_callback *
)
int
archive_read_open_FILE(
struct archive *
, FILE *file
)
int
archive_read_open_fd(
struct archive *
, int fd
, size_t block_size
)
int
archive_read_open_filename(
struct archive *
const char *filename
size_t block_size
)
int
archive_read_open_memory(
struct archive *
, void *buff
, size_t size
)
int
archive_read_next_header(
struct archive *
, struct archive_entry **
)
ssize_t
archive_read_data(
struct archive *
, void *buff
, size_t len
)
int
archive_read_data_block(
struct archive *
const void **buff
size_t *len
off_t *offset
)
int
archive_read_data_skip(
struct archive *
)
int
archive_read_data_into_buffer(
struct archive *
, void *
, ssize_t len
)
int
archive_read_data_into_fd(
struct archive *
, int fd
)
int
archive_read_extract(
struct archive *
struct archive_entry *
int flags
)
int
archive_read_extract2(
struct archive *src
struct archive_entry *
struct archive *dest
)
void
archive_read_extract_set_progress_callback(
struct archive *
void (*func)(void *)
void *user_data
)
int
archive_read_close(
struct archive *
)
int
archive_read_finish(
struct archive *
)
)
),
archive_read_support_compression_bzip2(
),
archive_read_support_compression_compress(
),
archive_read_support_compression_gzip(
),
archive_read_support_compression_none(
)
Enables auto-detection code and decompression support for the
specified compression.
Note that
``none''
is always enabled by default.
For convenience,
archive_read_support_compression_all(
)
enables all available decompression code.
)
),
archive_read_support_format_cpio(
),
archive_read_support_format_empty(
),
archive_read_support_format_iso9660(
),
archive_read_support_format_tar(
),
archive_read_support_format_zip(
)
Enables support---including auto-detection code---for the
specified archive format.
For example,
archive_read_support_format_tar(
)
enables support for a variety of standard tar formats, old-style tar,
ustar, pax interchange format, and many common variants.
For convenience,
archive_read_support_format_all(
)
enables support for all available formats.
Only empty archives are supported by default.
)
),
except that the skip callback is assumed to be
NULL
.
)
),
archive_read_open_FILE(
),
archive_read_open_fd(
),
or
archive_read_open_memory(
)
instead.
The library invokes the client-provided functions to obtain
raw bytes from the archive.
)
),
except that it accepts a
FILE *
pointer.
This function should not be used with tape drives or other devices
that require strict I/O blocking.
)
),
except that it accepts a file descriptor and block size rather than
a set of function pointers.
Note that the file descriptor will not be automatically closed at
end-of-archive.
This function is safe for use with tape drives or other blocked devices.
)
).
)
),
except that it accepts a simple filename and a block size.
A NULL filename represents standard input.
This function is safe for use with tape drives or other blocked devices.
)
),
except that it accepts a pointer and size of a block of
memory containing the archive data.
)
)
)
and fills any gaps with nulls so that callers see a single
continuous stream of data.
)
),
the
archive_read_data_block(
)
function avoids copying data and allows you to correctly handle
sparse files, as supported by some archive formats.
The library guarantees that offsets will increase and that blocks
will not overlap.
Note that the blocks returned from this function can be much larger
than the block size read from disk, due to compression
and internal buffer optimizations.
)
)
to skip all of the data for this archive entry.
)
)
instead.
)
)
to copy the entire entry to the provided file descriptor.
archive_read_extract_set_skip_file(
))
)
creates a restore object using
archive_write_disk_new(3)
and
archive_write_disk_set_standard_lookup(3),
then transparently invokes
archive_write_disk_set_options(3),
archive_write_header(3),
archive_write_data(3),
and
archive_write_finish_entry(3)
to create the entry on disk and copy data into it.
The
flags
argument is passed unmodified to
archive_write_disk_set_options(3).
)
)
that allows you to provide your own restore object.
In particular, this allows you to override the standard lookup functions
using
archive_write_disk_set_group_lookup(3),
and
archive_write_disk_set_user_lookup(3).
Note that
archive_read_extract2(
)
does not accept a
flags
argument; you should use
archive_write_disk_set_options(
)
to set the restore options yourself.
)
)
)
)
if it was not invoked manually, then release all resources.
Note: In libarchive 1.x, this function was declared to return
void
,
which made it impossible to detect certain errors when
archive_read_close(
)
was invoked implicitly from this function.
The declaration is corrected beginning with libarchive 2.0.
Note that the library determines most of the relevant information about the archive by inspection. In particular, it automatically detects gzip(1) or bzip2(1) compression and transparently performs the appropriate decompression. It also automatically detects the archive format.
A complete description of the struct archive and struct archive_entry objects can be found in the overview manual page for libarchive(3).
typedef
ssize_t
archive_read_callback(
struct archive *
void *client_data
const void **buffer
)
typedef
int
archive_skip_callback(
struct archive *
void *client_data
size_t request
)
typedef
int
archive_open_callback(
struct archive *
, void *client_data
)
typedef
int
archive_close_callback(
struct archive *
, void *client_data
)
The open callback is invoked by
archive_open().
It should return
ARCHIVE_OK
if the underlying file or data source is successfully
opened.
If the open fails, it should call
archive_set_error(
)
to register an error code and message and return
ARCHIVE_FATAL.
The read callback is invoked whenever the library
requires raw bytes from the archive.
The read callback should read data into a buffer,
set the
const
void
**buffer
argument to point to the available data, and
return a count of the number of bytes available.
The library will invoke the read callback again
only after it has consumed this data.
The library imposes no constraints on the size
of the data blocks returned.
On end-of-file, the read callback should
return zero.
On error, the read callback should invoke
archive_set_error()
to register an error code and message and
return -1.
The skip callback is invoked when the
library wants to ignore a block of data.
The return value is the number of bytes actually
skipped, which may differ from the request.
If the callback cannot skip data, it should return
zero.
If the skip callback is not provided (the
function pointer is
NULL
),
the library will invoke the read function
instead and simply discard the result.
A skip callback can provide significant
performance gains when reading uncompressed
archives from slow disk drives or other media
that can skip quickly.
The close callback is invoked by archive_close when
the archive processing is complete.
The callback should return
ARCHIVE_OK
on success.
On failure, the callback should invoke
archive_set_error()
to register an error code and message and
return
ARCHIVE_FATAL.
void
list_archive(const char *name)
{
struct mydata *mydata;
struct archive *a;
struct archive_entry *entry;
mydata = malloc(sizeof(struct mydata));
a = archive_read_new();
mydata->name = name;
archive_read_support_compression_all(a);
archive_read_support_format_all(a);
archive_read_open(a, mydata, myopen, myread, myclose);
while (archive_read_next_header(a, &entry) == ARCHIVE_OK) {
printf("%s\n",archive_entry_pathname(entry));
archive_read_data_skip(a);
}
archive_read_finish(a);
free(mydata);
}
ssize_t
myread(struct archive *a, void *client_data, const void **buff)
{
struct mydata *mydata = client_data;
*buff = mydata->buff;
return (read(mydata->fd, mydata->buff, 10240));
}
int
myopen(struct archive *a, void *client_data)
{
struct mydata *mydata = client_data;
mydata->fd = open(mydata->name, O_RDONLY);
return (mydata->fd >= 0 ? ARCHIVE_OK : ARCHIVE_FATAL);
}
int
myclose(struct archive *a, void *client_data)
{
struct mydata *mydata = client_data;
if (mydata->fd > 0)
close(mydata->fd);
return (ARCHIVE_OK);
}
)
and
archive_error_string(
)
functions.
archive_read_new()
returns a pointer to a freshly allocated
struct archive
object.
It returns
NULL
on error.
archive_read_data()
returns a count of bytes actually read or zero at the end of the entry.
On error, a value of
ARCHIVE_FATAL,
ARCHIVE_WARN,
or
ARCHIVE_RETRY
is returned and an error code and textual description can be retrieved from the
archive_errno(
)
and
archive_error_string(
)
functions.
The library expects the client callbacks to behave similarly.
If there is an error, you can use
archive_set_error()
to set an appropriate error code and description,
then return one of the non-zero values above.
(Note that the value eventually returned to the client may
not be the same; many errors that are not critical at the level
of basic I/O can prevent the archive from being properly read,
thus most I/O errors eventually cause
ARCHIVE_FATAL
to be returned.)
The libarchive library was written by Tim Kientzle <kientzle@acm.org>.