archive_read_open - archive_read_open, archive_read_open2, archive_read_open_fd, archive_read_open_FILE, archive_read_open_filename, functions for reading streaming archives
#include <archive.h> 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 *, const void *buff, size_t size);
ARCHIVE_READ_OPEN(3archive)
NAME
archive_read_open, archive_read_open2, archive_read_open_fd,
archive_read_open_FILE, archive_read_open_filename,
archive_read_open_memory - functions for reading streaming archives
LIBRARY
Streaming Archive Library (libarchive, -larchive)
SYNOPSIS
#include <archive.h>
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 *, const void *buff,
size_t size);
DESCRIPTION
archive_read_open()
The same as archive_read_open2(), except that the skip
callback is assumed to be NULL.
archive_read_open2()
Freeze the settings, open the archive, and prepare for
reading entries. This is the most generic version of this
call, which accepts four callback functions. Most clients
will want to use archive_read_open_filename(),
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.
archive_read_open_FILE()
Like archive_read_open(), 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.
archive_read_open_fd()
Like archive_read_open(), 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 auto-
matically closed at end-of-archive. This function is safe
for use with tape drives or other blocked devices.
archive_read_open_file()
This is a deprecated synonym for
archive_read_open_filename().
archive_read_open_filename()
Like archive_read_open(), 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.
archive_read_open_memory()
Like archive_read_open(), except that it accepts a pointer
and size of a block of memory containing the archive data.
A complete description of the Tn struct archive and Tn struct ar-
chive_entry objects can be found in the overview manual page for
libarchive(3).
CLIENT CALLBACKS
The callback functions must match the following prototypes:
typedef la_ssize_t archive_read_callback(struct archive *,
void *client_data, const void **buffer)
typedef la_int64_t archive_skip_callback(struct archive *,
void *client_data, off_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 AR-
CHIVE_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 num-
ber 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 func-
tion 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 pro-
cessing 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.
RETURN VALUES
These functions return ARCHIVE_OK on success, or ARCHIVE_FATAL.
ERRORS
Detailed error codes and textual descriptions are available from the
archive_errno() and archive_error_string() functions.
ATTRIBUTES
See attributes(7) for descriptions of the following attributes:
+---------------+--------------------+
|ATTRIBUTE TYPE | ATTRIBUTE VALUE |
+---------------+--------------------+
|Availability | library/libarchive |
+---------------+--------------------+
|Stability | Uncommitted |
+---------------+--------------------+
SEE ALSO
tar(1), archive_read(3), archive_read_data(3), archive_read_filter(3),
archive_read_format(3), archive_read_set_options(3), archive_util(3),
libarchive(3)
NOTES
Source code for open source software components in Oracle Solaris can
be found at https://www.oracle.com/downloads/opensource/solaris-source-
code-downloads.html.
This software was built from source available at
https://github.com/oracle/solaris-userland. The original community
source was downloaded from
https://github.com/libarchive/libarchive/releases/down-
load/v3.6.1/libarchive-3.6.1.tar.gz.
Further information about this software can be found on the open source
community website at http://www.libarchive.org/.
February 2, 2012
ARCHIVE_READ_OPEN(3archive)