.\" Copyright (c) 2003-2011 Tim Kientzle
.\" All rights reserved.
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.\" $FreeBSD$
.\"
.Dd February 2, 2012
.Dt ARCHIVE_READ_FILTER 3
.Os
.Sh NAME
.Nm archive_read_support_filter_all ,
.Nm archive_read_support_filter_bzip2 ,
.Nm archive_read_support_filter_compress ,
.Nm archive_read_support_filter_gzip ,
.Nm archive_read_support_filter_lzma ,
.Nm archive_read_support_filter_none ,
.Nm archive_read_support_filter_xz ,
.Nm archive_read_support_filter_program ,
.Nm archive_read_support_filter_program_signature
.Nd functions for reading streaming archives
.\"
.Sh LIBRARY
Streaming Archive Library (libarchive, -larchive)
.Sh SYNOPSIS
.In archive.h
.Ft int
.Fn archive_read_support_filter_all "struct archive *"
.Ft int
.Fn archive_read_support_filter_bzip2 "struct archive *"
.Ft int
.Fn archive_read_support_filter_compress "struct archive *"
.Ft int
.Fn archive_read_support_filter_gzip "struct archive *"
.Ft int
.Fn archive_read_support_filter_lzma "struct archive *"
.Ft int
.Fn archive_read_support_filter_none "struct archive *"
.Ft int
.Fn archive_read_support_filter_xz "struct archive *"
.Ft int
.Fo archive_read_support_filter_program
.Fa "struct archive *"
.Fa "const char *cmd"
.Fc
.Ft int
.Fo archive_read_support_filter_program_signature
.Fa "struct archive *"
.Fa "const char *cmd"
.Fa "const void *signature"
.Fa "size_t signature_length"
.Fc
.\"
.Sh DESCRIPTION
.Bl -tag -compact -width indent
.It Xo
.Fn archive_read_support_filter_bzip2 ,
.Fn archive_read_support_filter_compress ,
.Fn archive_read_support_filter_gzip ,
.Fn archive_read_support_filter_lzma ,
.Fn archive_read_support_filter_none ,
.Fn archive_read_support_filter_xz
.Xc
Enables auto-detection code and decompression support for the
specified compression.
These functions may fall back on external programs if an appropriate
library was not available at build time.
Decompression using an external program is usually slower than
decompression through built-in libraries.
Note that
.Dq none
is always enabled by default.
.It Fn archive_read_support_filter_all
Enables all available decompression filters.
.It Fn archive_read_support_filter_program
Data is fed through the specified external program before being dearchived.
Note that this disables automatic detection of the compression format,
so it makes no sense to specify this in conjunction with any other
decompression option.
.It Fn archive_read_support_filter_program_signature
This feeds data through the specified external program
but only if the initial bytes of the data match the specified
signature value.
.El
.\"
.\". Sh EXAMPLE
.\"
.Sh RETURN VALUES
These functions return
.Cm ARCHIVE_OK
if the compression is fully supported,
.Cm ARCHIVE_WARN
if the compression is supported only through an external program.
.Pp
.Fn archive_read_support_filter_none
always succeeds.
.\"
.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 libarchive 3 ,
.Xr archive_read 3 ,
.Xr archive_read_data 3 ,
.Xr archive_read_format 3 ,
.Xr archive_read_format 3