1 .\" Copyright (c) 2003-2011 Tim Kientzle
2 .\" All rights reserved.
4 .\" Redistribution and use in source and binary forms, with or without
5 .\" modification, are permitted provided that the following conditions
7 .\" 1. Redistributions of source code must retain the above copyright
8 .\" notice, this list of conditions and the following disclaimer.
9 .\" 2. Redistributions in binary form must reproduce the above copyright
10 .\" notice, this list of conditions and the following disclaimer in the
11 .\" documentation and/or other materials provided with the distribution.
13 .\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
14 .\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
15 .\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
16 .\" ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
17 .\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
18 .\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
19 .\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
20 .\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
21 .\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
22 .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
28 .Dt ARCHIVE_WRITE_OPEN 3
31 .Nm archive_write_open ,
32 .Nm archive_write_open_fd ,
33 .Nm archive_write_open_FILE ,
34 .Nm archive_write_open_filename ,
35 .Nm archive_write_open_memory
36 .Nd functions for creating archives
38 Streaming Archive Library (libarchive, -larchive)
42 .Fo archive_write_open
43 .Fa "struct archive *"
44 .Fa "void *client_data"
45 .Fa "archive_open_callback *"
46 .Fa "archive_write_callback *"
47 .Fa "archive_close_callback *"
50 .Fn archive_write_open_fd "struct archive *" "int fd"
52 .Fn archive_write_open_FILE "struct archive *" "FILE *file"
54 .Fn archive_write_open_filename "struct archive *" "const char *filename"
56 .Fo archive_write_open_memory
57 .Fa "struct archive *"
59 .Fa "size_t bufferSize"
63 .Bl -tag -width indent
64 .It Fn archive_write_open
65 Freeze the settings, open the archive, and prepare for writing entries.
66 This is the most generic form of this function, which accepts
67 pointers to three callback functions which will be invoked by
68 the compression layer to write the constructed archive.
69 This does not alter the default archive padding.
70 .It Fn archive_write_open_fd
72 .Fn archive_write_open
73 that accepts a file descriptor.
75 .Fn archive_write_open_fd
76 function is safe for use with tape drives or other
77 block-oriented devices.
78 .It Fn archive_write_open_FILE
80 .Fn archive_write_open
85 .Fn archive_write_open_FILE
86 is not safe for writing to tape drives or other devices
87 that require correct blocking.
88 .It Fn archive_write_open_file
89 A deprecated synonym for
90 .Fn archive_write_open_filename .
91 .It Fn archive_write_open_filename
93 .Fn archive_write_open
94 that accepts a filename.
95 A NULL argument indicates that the output should be written to standard output;
98 will open a file with that name.
99 If you have not invoked
100 .Fn archive_write_set_bytes_in_last_block ,
102 .Fn archive_write_open_filename
103 will adjust the last-block padding depending on the file:
104 it will enable padding when writing to standard output or
105 to a character or block device node, it will disable padding otherwise.
106 You can override this by manually invoking
107 .Fn archive_write_set_bytes_in_last_block
109 .Fn archive_write_open .
111 .Fn archive_write_open_filename
112 function is safe for use with tape drives or other
113 block-oriented devices.
114 .It Fn archive_write_open_memory
115 A convenience form of
116 .Fn archive_write_open
117 that accepts a pointer to a block of memory that will receive
121 argument points to a variable that will be updated
122 after each write to reflect how much of the buffer
124 You should be careful to ensure that this variable
125 remains allocated until after the archive is
127 This function will disable padding unless you
128 have specifically set the block size.
130 More information about the
132 object and the overall design of the library can be found in the
136 Note that the convenience forms above vary in how
137 they block the output.
139 .Xr archive_write_blocksize 3
140 if you need to control the block size used for writes
141 or the end-of-file padding behavior.
144 To use this library, you will need to define and register
145 callback functions that will be invoked to write data to the
147 These functions are registered by calling
148 .Fn archive_write_open :
149 .Bl -item -offset indent
152 .Fn archive_open_callback "struct archive *" "void *client_data"
155 The open callback is invoked by
156 .Fn archive_write_open .
159 if the underlying file or data source is successfully
161 If the open fails, it should call
162 .Fn archive_set_error
163 to register an error code and message and return
165 .Bl -item -offset indent
167 .Ft typedef la_ssize_t
168 .Fo archive_write_callback
169 .Fa "struct archive *"
170 .Fa "void *client_data"
171 .Fa "const void *buffer"
176 The write callback is invoked whenever the library
177 needs to write raw bytes to the archive.
178 For correct blocking, each call to the write callback function
179 should translate into a single
182 This is especially critical when writing archives to tape drives.
183 On success, the write callback should return the
184 number of bytes actually written.
185 On error, the callback should invoke
186 .Fn archive_set_error
187 to register an error code and message and return -1.
188 .Bl -item -offset indent
191 .Fn archive_close_callback "struct archive *" "void *client_data"
194 The close callback is invoked by archive_close when
195 the archive processing is complete.
196 The callback should return
199 On failure, the callback should invoke
200 .Fn archive_set_error
201 to register an error code and message and
205 Note that if the client-provided write callback function
206 returns a non-zero value, that error will be propagated back to the caller
207 through whatever API function resulted in that call, which
209 .Fn archive_write_header ,
210 .Fn archive_write_data ,
211 .Fn archive_write_close ,
212 .Fn archive_write_finish ,
214 .Fn archive_write_free .
215 The client callback can call
216 .Fn archive_set_error
217 to provide values that can then be retrieved by
220 .Fn archive_error_string .
223 These functions return
229 Detailed error codes and textual descriptions are available from the
232 .Fn archive_error_string
238 .Xr archive_write 3 ,
239 .Xr archive_write_blocksize 3 ,
240 .Xr archive_write_filter 3 ,
241 .Xr archive_write_format 3 ,
242 .Xr archive_write_new 3 ,
243 .Xr archive_write_set_options 3 ,