mirror of
https://github.com/freebsd/freebsd-src.git
synced 2024-11-28 09:02:44 +00:00
Merge from libarchive.googlecode.com r756,r761:
Document the new archive_read_disk API.
This commit is contained in:
Tim Kientzle
parent
f8c35626c4
commit
e1089c1e0c
Notes:
svn2git
2020-12-20 02:59:44 +00:00
svn path=/head/; revision=190957
@ -77,6 +77,7 @@ SRCS= archive_check_magic.c \
|
||||
# Man pages to be installed.
|
||||
MAN= archive_entry.3 \
|
||||
archive_read.3 \
|
||||
archive_read_disk.3 \
|
||||
archive_util.3 \
|
||||
archive_write.3 \
|
||||
archive_write_disk.3 \
|
||||
@ -186,6 +187,16 @@ MLINKS+= archive_read.3 archive_read_support_format_cpio.3
|
||||
MLINKS+= archive_read.3 archive_read_support_format_iso9660.3
|
||||
MLINKS+= archive_read.3 archive_read_support_format_tar.3
|
||||
MLINKS+= archive_read.3 archive_read_support_format_zip.3
|
||||
MLINKS+= archive_read_disk.3 archive_read_disk_entry_from_file.3
|
||||
MLINKS+= archive_read_disk.3 archive_read_disk_gname.3
|
||||
MLINKS+= archive_read_disk.3 archive_read_disk_new.3
|
||||
MLINKS+= archive_read_disk.3 archive_read_disk_set_gname_lookup.3
|
||||
MLINKS+= archive_read_disk.3 archive_read_disk_set_standard_lookup.3
|
||||
MLINKS+= archive_read_disk.3 archive_read_disk_set_symlink_hybrid.3
|
||||
MLINKS+= archive_read_disk.3 archive_read_disk_set_symlink_logical.3
|
||||
MLINKS+= archive_read_disk.3 archive_read_disk_set_symlink_physical.3
|
||||
MLINKS+= archive_read_disk.3 archive_read_disk_set_uname_lookup.3
|
||||
MLINKS+= archive_read_disk.3 archive_read_disk_uname.3
|
||||
MLINKS+= archive_util.3 archive_clear_error.3
|
||||
MLINKS+= archive_util.3 archive_compression.3
|
||||
MLINKS+= archive_util.3 archive_compression_name.3
|
||||
|
||||
308
lib/libarchive/archive_read_disk.3
Normal file
308
lib/libarchive/archive_read_disk.3
Normal file
@ -0,0 +1,308 @@
|
||||
.\" Copyright (c) 2003-2009 Tim Kientzle
|
||||
.\" All rights reserved.
|
||||
.\"
|
||||
.\" Redistribution and use in source and binary forms, with or without
|
||||
.\" modification, are permitted provided that the following conditions
|
||||
.\" are met:
|
||||
.\" 1. Redistributions of source code must retain the above copyright
|
||||
.\" notice, this list of conditions and the following disclaimer.
|
||||
.\" 2. Redistributions in binary form must reproduce the above copyright
|
||||
.\" notice, this list of conditions and the following disclaimer in the
|
||||
.\" documentation and/or other materials provided with the distribution.
|
||||
.\"
|
||||
.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
|
||||
.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
|
||||
.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
|
||||
.\" ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
|
||||
.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
|
||||
.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
|
||||
.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
|
||||
.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
|
||||
.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
|
||||
.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
|
||||
.\" SUCH DAMAGE.
|
||||
.\"
|
||||
.\" $FreeBSD$
|
||||
.\"
|
||||
.Dd March 10, 2009
|
||||
.Dt archive_read_disk 3
|
||||
.Os
|
||||
.Sh NAME
|
||||
.Nm archive_read_disk_new ,
|
||||
.Nm archive_read_disk_set_symlink_logical ,
|
||||
.Nm archive_read_disk_set_symlink_physical ,
|
||||
.Nm archive_read_disk_set_symlink_hybrid ,
|
||||
.Nm archive_read_disk_entry_from_file ,
|
||||
.Nm archive_read_disk_gname ,
|
||||
.Nm archive_read_disk_uname ,
|
||||
.Nm archive_read_disk_set_uname_lookup ,
|
||||
.Nm archive_read_disk_set_gname_lookup ,
|
||||
.Nm archive_read_disk_set_standard_lookup ,
|
||||
.Nm archive_read_close ,
|
||||
.Nm archive_read_finish
|
||||
.Nd functions for reading objects from disk
|
||||
.Sh SYNOPSIS
|
||||
.In archive.h
|
||||
.Ft struct archive *
|
||||
.Fn archive_read_disk_new "void"
|
||||
.Ft int
|
||||
.Fn archive_read_disk_set_symlink_logical "struct archive *"
|
||||
.Ft int
|
||||
.Fn archive_read_disk_set_symlink_physical "struct archive *"
|
||||
.Ft int
|
||||
.Fn archive_read_disk_set_symlink_hybrid "struct archive *"
|
||||
.Ft int
|
||||
.Fn archive_read_disk_gname "struct archive *" "gid_t"
|
||||
.Ft int
|
||||
.Fn archive_read_disk_uname "struct archive *" "uid_t"
|
||||
.Ft int
|
||||
.Fo archive_read_disk_set_gname_lookup
|
||||
.Fa "struct archive *"
|
||||
.Fa "void *"
|
||||
.Fa "const char *(*lookup)(void *, gid_t)"
|
||||
.Fa "void (*cleanup)(void *)"
|
||||
.Fc
|
||||
.Ft int
|
||||
.Fo archive_read_disk_set_uname_lookup
|
||||
.Fa "struct archive *"
|
||||
.Fa "void *"
|
||||
.Fa "const char *(*lookup)(void *, uid_t)"
|
||||
.Fa "void (*cleanup)(void *)"
|
||||
.Fc
|
||||
.Ft int
|
||||
.Fn archive_read_disk_set_standard_lookup "struct archive *"
|
||||
.Ft int
|
||||
.Fo archive_read_disk_entry_from_file
|
||||
.Fa "struct archive *"
|
||||
.Fa "struct archive_entry *"
|
||||
.Fa "int fd"
|
||||
.Fa "const struct stat *"
|
||||
.Fc
|
||||
.Ft int
|
||||
.Fn archive_read_close "struct archive *"
|
||||
.Ft int
|
||||
.Fn archive_read_finish "struct archive *"
|
||||
.Sh DESCRIPTION
|
||||
These functions provide an API for reading information about
|
||||
objects on disk.
|
||||
In particular, they provide an interface for populating
|
||||
.Tn struct archive_entry
|
||||
objects.
|
||||
.Bl -tag -width indent
|
||||
.It Fn archive_read_disk_new
|
||||
Allocates and initializes a
|
||||
.Tn struct archive
|
||||
object suitable for reading object information from disk.
|
||||
.It Xo
|
||||
.Fn archive_read_disk_set_symlink_logical ,
|
||||
.Fn archive_read_disk_set_symlink_physical ,
|
||||
.Fn archive_read_disk_set_symlink_hybrid
|
||||
.Xc
|
||||
This sets the mode used for handling symbolic links.
|
||||
The
|
||||
.Dq logical
|
||||
mode follows all symbolic links.
|
||||
The
|
||||
.Dq physical
|
||||
mode does not follow any symbolic links.
|
||||
The
|
||||
.Dq hybrid
|
||||
mode currently behaves identically to the
|
||||
.Dq logical
|
||||
mode.
|
||||
.It Xo
|
||||
.Fn archive_read_disk_gname ,
|
||||
.Fn archive_read_disk_uname
|
||||
.Xc
|
||||
Returns a user or group name given a gid or uid value.
|
||||
By default, these always return a NULL string.
|
||||
.It Xo
|
||||
.Fn archive_read_disk_set_gname_lookup ,
|
||||
.Fn archive_read_disk_set_uname_lookup
|
||||
.Xc
|
||||
These allow you to override the functions used for
|
||||
user and group name lookups.
|
||||
You may also provide a
|
||||
.Tn void *
|
||||
pointer to a private data structure and a cleanup function for
|
||||
that data.
|
||||
The cleanup function will be invoked when the
|
||||
.Tn struct archive
|
||||
object is destroyed or when new lookup functions are registered.
|
||||
.It Fn archive_read_disk_set_standard_lookup
|
||||
This convenience function installs a standard set of user
|
||||
and group name lookup functions.
|
||||
These functions use
|
||||
.Xr getpwid 3
|
||||
and
|
||||
.Xr getgrid 3
|
||||
to convert ids to names, defaulting to NULL if the names cannot
|
||||
be looked up.
|
||||
These functions also implement a simple memory cache to reduce
|
||||
the number of calls to
|
||||
.Xr getpwid 3
|
||||
and
|
||||
.Xr getgrid 3 .
|
||||
.It Fn archive_read_disk_entry_from_file
|
||||
Populates a
|
||||
.Tn struct archive_entry
|
||||
object with information about a particular file.
|
||||
The
|
||||
.Tn archive_entry
|
||||
object must have already been created with
|
||||
.Xr archive_entry_new 3
|
||||
and at least one of the source path or path fields must already be set.
|
||||
(If both are set, the source path will be used.)
|
||||
.Pp
|
||||
Information is read from disk using the path name from the
|
||||
.Tn struct archive_entry
|
||||
object.
|
||||
If a file descriptor is provided, some information will be obtained using
|
||||
that file descriptor, on platforms that support the appropriate
|
||||
system calls.
|
||||
.Pp
|
||||
If a pointer to a
|
||||
.Tn struct stat
|
||||
is provided, information from that structure will be used instead
|
||||
of reading from the disk where appropriate.
|
||||
This can provide performance benefits in scenarios where
|
||||
.Tn struct stat
|
||||
information has already been read from the disk as a side effect
|
||||
of some other operation.
|
||||
(For example, directory traversal libraries often provide this information.)
|
||||
.Pp
|
||||
Where necessary, user and group ids are converted to user and group names
|
||||
using the currently registered lookup functions above.
|
||||
This affects the file ownership fields and ACL values in the
|
||||
.Tn struct archive_entry
|
||||
object.
|
||||
.It Fn archive_read_close
|
||||
This currently does nothing.
|
||||
.It Fn archive_write_finish
|
||||
Invokes
|
||||
.Fn archive_write_close
|
||||
if it was not invoked manually, then releases all resources.
|
||||
.El
|
||||
More information about the
|
||||
.Va struct archive
|
||||
object and the overall design of the library can be found in the
|
||||
.Xr libarchive 3
|
||||
overview.
|
||||
.Sh EXAMPLE
|
||||
The following illustrates basic usage of the library by
|
||||
showing how to use it to copy an item on disk into an archive.
|
||||
.Bd -literal -offset indent
|
||||
void
|
||||
file_to_archive(struct archive *a, const char *name)
|
||||
{
|
||||
char buff[8192];
|
||||
size_t bytes_read;
|
||||
struct archive *ard;
|
||||
struct archive_entry *entry;
|
||||
int fd;
|
||||
|
||||
ard = archive_read_disk_new();
|
||||
archive_read_disk_set_standard_lookup(ard);
|
||||
entry = archive_entry_new();
|
||||
fd = open(name, O_RDONLY);
|
||||
if (fd < 0)
|
||||
return;
|
||||
archive_entry_copy_sourcepath(entry, name);
|
||||
archive_read_disk_entry_from_file(ard, entry, fd, NULL);
|
||||
archive_write_header(a, entry);
|
||||
while ((bytes_read = read(fd, buff, sizeof(buff))) > 0)
|
||||
archive_write_data(a, buff, bytes_read);
|
||||
archive_write_finish_entry(a);
|
||||
archive_read_finish(ard);
|
||||
archive_entry_free(entry);
|
||||
}
|
||||
.Ed
|
||||
.Sh RETURN VALUES
|
||||
Most functions return
|
||||
.Cm ARCHIVE_OK
|
||||
(zero) on success, or one of several negative
|
||||
error codes for errors.
|
||||
Specific error codes include:
|
||||
.Cm ARCHIVE_RETRY
|
||||
for operations that might succeed if retried,
|
||||
.Cm ARCHIVE_WARN
|
||||
for unusual conditions that do not prevent further operations, and
|
||||
.Cm ARCHIVE_FATAL
|
||||
for serious errors that make remaining operations impossible.
|
||||
The
|
||||
.Xr archive_errno 3
|
||||
and
|
||||
.Xr archive_error_string 3
|
||||
functions can be used to retrieve an appropriate error code and a
|
||||
textual error message.
|
||||
(See
|
||||
.Xr archive_util 3
|
||||
for details.)
|
||||
.Pp
|
||||
.Fn archive_read_disk_new
|
||||
returns a pointer to a newly-allocated
|
||||
.Tn struct archive
|
||||
object or NULL if the allocation failed for any reason.
|
||||
.Pp
|
||||
.Fn archive_read_disk_gname
|
||||
and
|
||||
.Fn archive_read_disk_uname
|
||||
return
|
||||
.Tn const char *
|
||||
pointers to the textual name or NULL if the lookup failed for any reason.
|
||||
The returned pointer points to internal storage that
|
||||
may be reused on the next call to either of these functions;
|
||||
callers should copy the string if they need to continue accessing it.
|
||||
.Pp
|
||||
.Sh SEE ALSO
|
||||
.Xr archive_read 3 ,
|
||||
.Xr archive_write 3 ,
|
||||
.Xr archive_write_disk 3 ,
|
||||
.Xr tar 1 ,
|
||||
.Xr libarchive 3
|
||||
.Sh HISTORY
|
||||
The
|
||||
.Nm libarchive
|
||||
library first appeared in
|
||||
.Fx 5.3 .
|
||||
The
|
||||
.Nm archive_read_disk
|
||||
interface was added to
|
||||
.Nm libarchive 2.6
|
||||
and first appeared in
|
||||
.Fx 8.0 .
|
||||
.Sh AUTHORS
|
||||
.An -nosplit
|
||||
The
|
||||
.Nm libarchive
|
||||
library was written by
|
||||
.An Tim Kientzle Aq kientzle@freebsd.org .
|
||||
.Sh BUGS
|
||||
The
|
||||
.Dq standard
|
||||
user name and group name lookup functions are not the defaults because
|
||||
.Xr getgrid 3
|
||||
and
|
||||
.Xr getpwid 3
|
||||
are sometimes too large for particular applications.
|
||||
The current design allows the application author to use a more
|
||||
compact implementation when appropriate.
|
||||
.Pp
|
||||
The full list of metadata read from disk by
|
||||
.Fn archive_read_disk_entry_from_file
|
||||
is necessarily system-dependent.
|
||||
.Pp
|
||||
The
|
||||
.Fn archive_read_disk_entry_from_file
|
||||
function reads as much information as it can from disk.
|
||||
Some method should be provided to limit this so that clients who
|
||||
do not need ACLs, for instance, can avoid the extra work needed
|
||||
to look up such information.
|
||||
.Pp
|
||||
This API should provide a set of methods for walking a directory tree.
|
||||
That would make it a direct parallel of the
|
||||
.Xr archive_read 3
|
||||
API.
|
||||
When such methods are implemented, the
|
||||
.Dq hybrid
|
||||
symbolic link mode will make sense.
|
||||
Loading…
Reference in New Issue
Block a user