1AR(1) GNU Development Tools AR(1)
2
6 ar - create, modify, and extract from archives
7
9 ar [-X32_64] [-]p[mod] [--plugin name] [--target bfdname] [--output
10 dirname] [relpos] [count] archive [member...]
11
13 The GNU ar program creates, modifies, and extracts from archives. An
14 archive is a single file holding a collection of other files in a
15 structure that makes it possible to retrieve the original individual
16 files (called members of the archive).
17 The original files' contents, mode (permissions), timestamp, owner, and
19 group are preserved in the archive, and can be restored on extraction.
20 GNU ar can maintain archives whose members have names of any length;
22 however, depending on how ar is configured on your system, a limit on
23 member-name length may be imposed for compatibility with archive
24 formats maintained with other tools. If it exists, the limit is often
25 15 characters (typical of formats related to a.out) or 16 characters
26 (typical of formats related to coff).
27 ar is considered a binary utility because archives of this sort are
29 most often used as libraries holding commonly needed subroutines.
30 ar creates an index to the symbols defined in relocatable object
32 modules in the archive when you specify the modifier s. Once created,
33 this index is updated in the archive whenever ar makes a change to its
34 contents (save for the q update operation). An archive with such an
35 index speeds up linking to the library, and allows routines in the
36 library to call each other without regard to their placement in the
37 archive.
38 You may use nm -s or nm --print-armap to list this index table. If an
40 archive lacks the table, another form of ar called ranlib can be used
41 to add just the table.
42 GNU ar can optionally create a thin archive, which contains a symbol
44 index and references to the original copies of the member files of the
45 archive. This is useful for building libraries for use within a local
46 build tree, where the relocatable objects are expected to remain
47 available, and copying the contents of each object would only waste
48 time and space.
49 An archive can either be thin or it can be normal. It cannot be both
51 at the same time. Once an archive is created its format cannot be
52 changed without first deleting it and then creating a new archive in
53 its place.
54 Thin archives are also flattened, so that adding one thin archive to
56 another thin archive does not nest it, as would happen with a normal
57 archive. Instead the elements of the first archive are added
58 individually to the second archive.
59 The paths to the elements of the archive are stored relative to the
61 archive itself.
62 GNU ar is designed to be compatible with two different facilities. You
64 can control its activity using command-line options, like the different
65 varieties of ar on Unix systems; or, if you specify the single command-
66 line option -M, you can control it with a script supplied via standard
67 input, like the MRI "librarian" program.
68
70 GNU ar allows you to mix the operation code p and modifier flags mod in
71 any order, within the first command-line argument.
72 If you wish, you may begin the first command-line argument with a dash.
74 The p keyletter specifies what operation to execute; it may be any of
76 the following, but you must specify only one of them:
77 d Delete modules from the archive. Specify the names of modules to
79 be deleted as member...; the archive is untouched if you specify no
80 files to delete.
81 If you specify the v modifier, ar lists each module as it is
83 deleted.
84 m Use this operation to move members in an archive.
86 The ordering of members in an archive can make a difference in how
88 programs are linked using the library, if a symbol is defined in
89 more than one member.
90 If no modifiers are used with "m", any members you name in the
92 member arguments are moved to the end of the archive; you can use
93 the a, b, or i modifiers to move them to a specified place instead.
94 p Print the specified members of the archive, to the standard output
96 file. If the v modifier is specified, show the member name before
97 copying its contents to standard output.
98 If you specify no member arguments, all the files in the archive
100 are printed.
101 q Quick append; Historically, add the files member... to the end of
103 archive, without checking for replacement.
104 The modifiers a, b, and i do not affect this operation; new members
106 are always placed at the end of the archive.
107 The modifier v makes ar list each file as it is appended.
109 Since the point of this operation is speed, implementations of ar
111 have the option of not updating the archive's symbol table if one
112 exists. Too many different systems however assume that symbol
113 tables are always up-to-date, so GNU ar will rebuild the table even
114 with a quick append.
115 Note - GNU ar treats the command qs as a synonym for r - replacing
117 already existing files in the archive and appending new ones at the
118 end.
119 r Insert the files member... into archive (with replacement). This
121 operation differs from q in that any previously existing members
122 are deleted if their names match those being added.
123 If one of the files named in member... does not exist, ar displays
125 an error message, and leaves undisturbed any existing members of
126 the archive matching that name.
127 By default, new members are added at the end of the file; but you
129 may use one of the modifiers a, b, or i to request placement
130 relative to some existing member.
131 The modifier v used with this operation elicits a line of output
133 for each file inserted, along with one of the letters a or r to
134 indicate whether the file was appended (no old member deleted) or
135 replaced.
136 s Add an index to the archive, or update it if it already exists.
138 Note this command is an exception to the rule that there can only
139 be one command letter, as it is possible to use it as either a
140 command or a modifier. In either case it does the same thing.
141 t Display a table listing the contents of archive, or those of the
143 files listed in member... that are present in the archive.
144 Normally only the member name is shown, but if the modifier O is
145 specified, then the corresponding offset of the member is also
146 displayed. Finally, in order to see the modes (permissions),
147 timestamp, owner, group, and size the v modifier should be
148 included.
149 If you do not specify a member, all files in the archive are
151 listed.
152 If there is more than one file with the same name (say, fie) in an
154 archive (say b.a), ar t b.a fie lists only the first instance; to
155 see them all, you must ask for a complete listing---in our example,
156 ar t b.a.
157 x Extract members (named member) from the archive. You can use the v
159 modifier with this operation, to request that ar list each name as
160 it extracts it.
161 If you do not specify a member, all files in the archive are
163 extracted.
164 Files cannot be extracted from a thin archive, and there are
166 restrictions on extracting from archives created with P: The paths
167 must not be absolute, may not contain "..", and any subdirectories
168 in the paths must exist. If it is desired to avoid these
169 restrictions then used the --output option to specify an output
170 directory.
171 A number of modifiers (mod) may immediately follow the p keyletter, to
173 specify variations on an operation's behavior:
174 a Add new files after an existing member of the archive. If you use
176 the modifier a, the name of an existing archive member must be
177 present as the relpos argument, before the archive specification.
178 b Add new files before an existing member of the archive. If you use
180 the modifier b, the name of an existing archive member must be
181 present as the relpos argument, before the archive specification.
182 (same as i).
183 c Create the archive. The specified archive is always created if it
185 did not exist, when you request an update. But a warning is issued
186 unless you specify in advance that you expect to create it, by
187 using this modifier.
188 D Operate in deterministic mode. When adding files and the archive
190 index use zero for UIDs, GIDs, timestamps, and use consistent file
191 modes for all files. When this option is used, if ar is used with
192 identical options and identical input files, multiple runs will
193 create identical output files regardless of the input files'
194 owners, groups, file modes, or modification times.
195 If binutils was configured with --enable-deterministic-archives,
197 then this mode is on by default. It can be disabled with the U
198 modifier, below.
199 f Truncate names in the archive. GNU ar will normally permit file
201 names of any length. This will cause it to create archives which
202 are not compatible with the native ar program on some systems. If
203 this is a concern, the f modifier may be used to truncate file
204 names when putting them in the archive.
205 i Insert new files before an existing member of the archive. If you
207 use the modifier i, the name of an existing archive member must be
208 present as the relpos argument, before the archive specification.
209 (same as b).
210 l This modifier is accepted but not used.
212 N Uses the count parameter. This is used if there are multiple
214 entries in the archive with the same name. Extract or delete
215 instance count of the given name from the archive.
216 o Preserve the original dates of members when extracting them. If
218 you do not specify this modifier, files extracted from the archive
219 are stamped with the time of extraction.
220 O Display member offsets inside the archive. Use together with the t
222 option.
223 P Use the full path name when matching or storing names in the
225 archive. Archives created with full path names are not POSIX
226 compliant, and thus may not work with tools other than up to date
227 GNU tools. Modifying such archives with GNU ar without using P
228 will remove the full path names unless the archive is a thin
229 archive. Note that P may be useful when adding files to a thin
230 archive since r without P ignores the path when choosing which
231 element to replace. Thus
232 ar rcST archive.a subdir/file1 subdir/file2 file1
234 will result in the first "subdir/file1" being replaced with "file1"
236 from the current directory. Adding P will prevent this
237 replacement.
238 s Write an object-file index into the archive, or update an existing
240 one, even if no other change is made to the archive. You may use
241 this modifier flag either with any operation, or alone. Running ar
242 s on an archive is equivalent to running ranlib on it.
243 S Do not generate an archive symbol table. This can speed up
245 building a large library in several steps. The resulting archive
246 can not be used with the linker. In order to build a symbol table,
247 you must omit the S modifier on the last execution of ar, or you
248 must run ranlib on the archive.
249 T Make the specified archive a thin archive. If it already exists
251 and is a regular archive, the existing members must be present in
252 the same directory as archive.
253 u Normally, ar r... inserts all files listed into the archive. If
255 you would like to insert only those of the files you list that are
256 newer than existing members of the same names, use this modifier.
257 The u modifier is allowed only for the operation r (replace). In
258 particular, the combination qu is not allowed, since checking the
259 timestamps would lose any speed advantage from the operation q.
260 U Do not operate in deterministic mode. This is the inverse of the D
262 modifier, above: added files and the archive index will get their
263 actual UID, GID, timestamp, and file mode values.
264 This is the default unless binutils was configured with
266 --enable-deterministic-archives.
267 v This modifier requests the verbose version of an operation. Many
269 operations display additional information, such as filenames
270 processed, when the modifier v is appended.
271 V This modifier shows the version number of ar.
273 The ar program also supports some command-line options which are
275 neither modifiers nor actions, but which do change its behaviour in
276 specific ways:
277 --help
279 Displays the list of command-line options supported by ar and then
280 exits.
281 --version
283 Displays the version information of ar and then exits.
284 -X32_64
286 ar ignores an initial option spelled -X32_64, for compatibility
287 with AIX. The behaviour produced by this option is the default for
288 GNU ar. ar does not support any of the other -X options; in
289 particular, it does not support -X32 which is the default for AIX
290 ar.
291 --plugin name
293 The optional command-line switch --plugin name causes ar to load
294 the plugin called name which adds support for more file formats,
295 including object files with link-time optimization information.
296 This option is only available if the toolchain has been built with
298 plugin support enabled.
299 If --plugin is not provided, but plugin support has been enabled
301 then ar iterates over the files in ${libdir}/bfd-plugins in
302 alphabetic order and the first plugin that claims the object in
303 question is used.
304 Please note that this plugin search directory is not the one used
306 by ld's -plugin option. In order to make ar use the linker plugin
307 it must be copied into the ${libdir}/bfd-plugins directory. For
308 GCC based compilations the linker plugin is called
309 liblto_plugin.so.0.0.0. For Clang based compilations it is called
310 LLVMgold.so. The GCC plugin is always backwards compatible with
311 earlier versions, so it is sufficient to just copy the newest one.
312 --target target
314 The optional command-line switch --target bfdname specifies that
315 the archive members are in an object code format different from
316 your system's default format. See
317 --output dirname
319 The --output option can be used to specify a path to a directory
320 into which archive members should be extracted. If this option is
321 not specified then the current directory will be used.
322 Note - although the presence of this option does imply a x
324 extraction operation that option must still be included on the
325 command line.
326 @file
328 Read command-line options from file. The options read are inserted
329 in place of the original @file option. If file does not exist, or
330 cannot be read, then the option will be treated literally, and not
331 removed.
332 Options in file are separated by whitespace. A whitespace
334 character may be included in an option by surrounding the entire
335 option in either single or double quotes. Any character (including
336 a backslash) may be included by prefixing the character to be
337 included with a backslash. The file may itself contain additional
338 @file options; any such options will be processed recursively.
339
341 nm(1), ranlib(1), and the Info entries for binutils.
342
344 Copyright (c) 1991-2020 Free Software Foundation, Inc.
345 Permission is granted to copy, distribute and/or modify this document
347 under the terms of the GNU Free Documentation License, Version 1.3 or
348 any later version published by the Free Software Foundation; with no
349 Invariant Sections, with no Front-Cover Texts, and with no Back-Cover
350 Texts. A copy of the license is included in the section entitled "GNU
351 Free Documentation License".
352binutils-2.34 2021-01-28 AR(1)