NAME¶
archive_clear_error
,
archive_compression
,
archive_compression_name
,
archive_copy_error
,
archive_errno
,
archive_error_string
,
archive_file_count
,
archive_filter_code
,
archive_filter_count
,
archive_filter_name
,
archive_format
,
archive_format_name
,
archive_position
,
archive_set_error
—
libarchive utility functions
LIBRARY¶
Streaming Archive Library (libarchive, -larchive)
SYNOPSIS¶
#include
<archive.h>
void
archive_clear_error
(
struct
archive *);
int
archive_compression
(
struct
archive *);
const char *
archive_compression_name
(
struct
archive *);
void
archive_copy_error
(
struct
archive *,
struct archive
*);
int
archive_errno
(
struct
archive *);
const char *
archive_error_string
(
struct
archive *);
int
archive_file_count
(
struct
archive *);
int
archive_filter_code
(
struct
archive *,
int);
int
archive_filter_count
(
struct
archive *,
int);
const char *
archive_filter_name
(
struct
archive *,
int);
int
archive_format
(
struct
archive *);
const char *
archive_format_name
(
struct
archive *);
int64_t
archive_position
(
struct
archive *,
int);
void
archive_set_error
(
struct
archive *,
int error_code,
const char *fmt,
...);
DESCRIPTION¶
These functions provide access to various information about the struct archive
object used in the
libarchive(3) library.
archive_clear_error
()
- Clears any error information left over from a previous call. Not generally
used in client code.
archive_compression
()
- Synonym for
archive_filter_code(a,
(0)).
archive_compression_name
()
- Synonym for
archive_filter_name(a,
(0)).
archive_copy_error
()
- Copies error information from one archive to another.
archive_errno
()
- Returns a numeric error code (see errno(2))
indicating the reason for the most recent error return. Note that this can
not be reliably used to detect whether an error has occurred. It should be
used only after another libarchive function has returned an error
status.
archive_error_string
()
- Returns a textual error message suitable for display. The error message
here is usually more specific than that obtained from passing the result
of
archive_errno
() to
strerror(3).
archive_file_count
()
- Returns a count of the number of files processed by this archive object.
The count is incremented by calls to
archive_write_header(3) or
archive_read_next_header(3).
archive_filter_code
()
- Returns a numeric code identifying the indicated filter. See
archive_filter_count
() for details of
the numbering.
archive_filter_count
()
- Returns the number of filters in the current pipeline. For read archive
handles, these filters are added automatically by the automatic format
detection. For write archive handles, these filters are added by calls to
the various
archive_write_add_filter_XXX
()
functions. Filters in the resulting pipeline are numbered so that filter 0
is the filter closest to the format handler. As a convenience, functions
that expect a filter number will accept -1 as a synonym for the
highest-numbered filter.
For example, when reading a uuencoded gzipped tar archive, there are three
filters: filter 0 is the gunzip filter, filter 1 is the uudecode filter,
and filter 2 is the pseudo-filter that wraps the archive read functions.
In this case, requesting
archive_position(a,
(-1))
would be a synonym for
archive_position(a,
(2))
which would return the number of bytes currently read from the archive,
while
archive_position(a,
(1))
would return the number of bytes after uudecoding, and
archive_position(a,
(0))
would return the number of bytes after decompression.
archive_filter_name
()
- Returns a textual name identifying the indicated filter. See
archive_filter_count
() for details of
the numbering.
archive_format
()
- Returns a numeric code indicating the format of the current archive entry.
This value is set by a successful call to
archive_read_next_header
(). Note that
it is common for this value to change from entry to entry. For example, a
tar archive might have several entries that utilize GNU tar extensions and
several entries that do not. These entries will have different format
codes.
archive_format_name
()
- A textual description of the format of the current entry.
archive_position
()
- Returns the number of bytes read from or written to the indicated filter.
In particular,
archive_position(a,
(0))
returns the number of bytes read or written by the format handler, while
archive_position(a,
(-1))
returns the number of bytes read or written to the archive. See
archive_filter_count
() for details of
the numbering here.
archive_set_error
()
- Sets the numeric error code and error description that will be returned by
archive_errno
() and
archive_error_string
(). This function
should be used within I/O callbacks to set system-specific error codes and
error descriptions. This function accepts a printf-like format string and
arguments. However, you should be careful to use only the following printf
format specifiers: “%c”, “%d”,
“%jd”, “%jo”, “%ju”,
“%jx”, “%ld”, “%lo”,
“%lu”, “%lx”, “%o”,
“%u”, “%s”, “%x”,
“%%”. Field-width specifiers and other printf features are
not uniformly supported and should not be used.
SEE ALSO¶
archive_read(3),
archive_write(3),
libarchive(3),
printf(3)
HISTORY¶
The
libarchive
library first appeared in
FreeBSD 5.3.
AUTHORS¶
The
libarchive
library was written by
Tim Kientzle
⟨kientzle@acm.org⟩.