.\" Copyright (c) 2003-2011 Tim Kientzle

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.\" $FreeBSD$

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.Dd February 2, 2012

.Dt ARCHIVE_READ_EXTRACT 3

.Os

.Sh NAME

.Nm archive_read_extract ,

.Nm archive_read_extract2 ,

.Nm archive_read_extract_set_progress_callback

.Nd functions for reading streaming archives

.Sh LIBRARY

Streaming Archive Library (libarchive, -larchive)

.Sh SYNOPSIS

.In archive.h

.Ft int

.Fo archive_read_extract

.Fa "struct archive *"

.Fa "struct archive_entry *"

.Fa "int flags"

.Fc

.Ft int

.Fo archive_read_extract2

.Fa "struct archive *src"

.Fa "struct archive_entry *"

.Fa "struct archive *dest"

.Fc

.Ft void

.Fo archive_read_extract_set_progress_callback

.Fa "struct archive *"

.Fa "void (*func)(void *)"

.Fa "void *user_data"

.Fc

.Sh DESCRIPTION

.Bl -tag -compact -width indent

.It Fn archive_read_extract , Fn archive_read_extract_set_skip_file

A convenience function that wraps the corresponding

.Xr archive_write_disk 3

interfaces.

The first call to

.Fn archive_read_extract

creates a restore object using

.Xr archive_write_disk_new 3

and

.Xr archive_write_disk_set_standard_lookup 3 ,

then transparently invokes

.Xr archive_write_disk_set_options 3 ,

.Xr archive_write_header 3 ,

.Xr archive_write_data 3 ,

and

.Xr archive_write_finish_entry 3

to create the entry on disk and copy data into it.

The

.Va flags

argument is passed unmodified to

.Xr archive_write_disk_set_options 3 .

.It Fn archive_read_extract2

This is another version of

.Fn archive_read_extract

that allows you to provide your own restore object.

In particular, this allows you to override the standard lookup functions

using

.Xr archive_write_disk_set_group_lookup 3 ,

and

.Xr archive_write_disk_set_user_lookup 3 .

Note that

.Fn archive_read_extract2

does not accept a

.Va flags

argument; you should use

.Fn archive_write_disk_set_options

to set the restore options yourself.

.It Fn archive_read_extract_set_progress_callback

Sets a pointer to a user-defined callback that can be used

for updating progress displays during extraction.

The progress function will be invoked during the extraction of large

regular files.

The progress function will be invoked with the pointer provided to this call.

Generally, the data pointed to should include a reference to the archive

object and the archive_entry object so that various statistics

can be retrieved for the progress display.

.El

.\"

.Sh RETURN VALUES

Most functions return zero on success, non-zero on error.

The possible return codes include:

.Cm ARCHIVE_OK

(the operation succeeded),

.Cm ARCHIVE_WARN

(the operation succeeded but a non-critical error was encountered),

.Cm ARCHIVE_EOF

(end-of-archive was encountered),

.Cm ARCHIVE_RETRY

(the operation failed but can be retried),

and

.Cm ARCHIVE_FATAL

(there was a fatal error; the archive should be closed immediately).

.Sh ERRORS

Detailed error codes and textual descriptions are available from the

.Fn archive_errno

and

.Fn archive_error_string

functions.

.Sh SEE ALSO

.Xr tar 1 ,

.Xr libarchive 3 ,

.Xr archive_read 3 ,

.Xr archive_read_data 3 ,

.Xr archive_read_filter 3 ,

.Xr archive_read_format 3 ,

.Xr archive_read_open 3 ,

.Xr archive_read_set_options 3 ,

.Xr archive_util 3 ,

.Xr tar 5