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] [--record-libdeps libdeps] [--thin] [relpos] [count] archive
11 [member...]
12
14 The GNU ar program creates, modifies, and extracts from archives. An
15 archive is a single file holding a collection of other files in a
16 structure that makes it possible to retrieve the original individual
17 files (called members of the archive).
18 The original files' contents, mode (permissions), timestamp, owner, and
20 group are preserved in the archive, and can be restored on extraction.
21 GNU ar can maintain archives whose members have names of any length;
23 however, depending on how ar is configured on your system, a limit on
24 member-name length may be imposed for compatibility with archive
25 formats maintained with other tools. If it exists, the limit is often
26 15 characters (typical of formats related to a.out) or 16 characters
27 (typical of formats related to coff).
28 ar is considered a binary utility because archives of this sort are
30 most often used as libraries holding commonly needed subroutines.
31 Since libraries often will depend on other libraries, ar can also
32 record the dependencies of a library when the --record-libdeps option
33 is specified.
34 ar creates an index to the symbols defined in relocatable object
36 modules in the archive when you specify the modifier s. Once created,
37 this index is updated in the archive whenever ar makes a change to its
38 contents (save for the q update operation). An archive with such an
39 index speeds up linking to the library, and allows routines in the
40 library to call each other without regard to their placement in the
41 archive.
42 You may use nm -s or nm --print-armap to list this index table. If an
44 archive lacks the table, another form of ar called ranlib can be used
45 to add just the table.
46 GNU ar can optionally create a thin archive, which contains a symbol
48 index and references to the original copies of the member files of the
49 archive. This is useful for building libraries for use within a local
50 build tree, where the relocatable objects are expected to remain
51 available, and copying the contents of each object would only waste
52 time and space.
53 An archive can either be thin or it can be normal. It cannot be both
55 at the same time. Once an archive is created its format cannot be
56 changed without first deleting it and then creating a new archive in
57 its place.
58 Thin archives are also flattened, so that adding one thin archive to
60 another thin archive does not nest it, as would happen with a normal
61 archive. Instead the elements of the first archive are added
62 individually to the second archive.
63 The paths to the elements of the archive are stored relative to the
65 archive itself.
66 GNU ar is designed to be compatible with two different facilities. You
68 can control its activity using command-line options, like the different
69 varieties of ar on Unix systems; or, if you specify the single command-
70 line option -M, you can control it with a script supplied via standard
71 input, like the MRI "librarian" program.
72
74 GNU ar allows you to mix the operation code p and modifier flags mod in
75 any order, within the first command-line argument.
76 If you wish, you may begin the first command-line argument with a dash.
78 The p keyletter specifies what operation to execute; it may be any of
80 the following, but you must specify only one of them:
81 d Delete modules from the archive. Specify the names of modules to
83 be deleted as member...; the archive is untouched if you specify no
84 files to delete.
85 If you specify the v modifier, ar lists each module as it is
87 deleted.
88 m Use this operation to move members in an archive.
90 The ordering of members in an archive can make a difference in how
92 programs are linked using the library, if a symbol is defined in
93 more than one member.
94 If no modifiers are used with "m", any members you name in the
96 member arguments are moved to the end of the archive; you can use
97 the a, b, or i modifiers to move them to a specified place instead.
98 p Print the specified members of the archive, to the standard output
100 file. If the v modifier is specified, show the member name before
101 copying its contents to standard output.
102 If you specify no member arguments, all the files in the archive
104 are printed.
105 q Quick append; Historically, add the files member... to the end of
107 archive, without checking for replacement.
108 The modifiers a, b, and i do not affect this operation; new members
110 are always placed at the end of the archive.
111 The modifier v makes ar list each file as it is appended.
113 Since the point of this operation is speed, implementations of ar
115 have the option of not updating the archive's symbol table if one
116 exists. Too many different systems however assume that symbol
117 tables are always up-to-date, so GNU ar will rebuild the table even
118 with a quick append.
119 Note - GNU ar treats the command qs as a synonym for r - replacing
121 already existing files in the archive and appending new ones at the
122 end.
123 r Insert the files member... into archive (with replacement). This
125 operation differs from q in that any previously existing members
126 are deleted if their names match those being added.
127 If one of the files named in member... does not exist, ar displays
129 an error message, and leaves undisturbed any existing members of
130 the archive matching that name.
131 By default, new members are added at the end of the file; but you
133 may use one of the modifiers a, b, or i to request placement
134 relative to some existing member.
135 The modifier v used with this operation elicits a line of output
137 for each file inserted, along with one of the letters a or r to
138 indicate whether the file was appended (no old member deleted) or
139 replaced.
140 s Add an index to the archive, or update it if it already exists.
142 Note this command is an exception to the rule that there can only
143 be one command letter, as it is possible to use it as either a
144 command or a modifier. In either case it does the same thing.
145 t Display a table listing the contents of archive, or those of the
147 files listed in member... that are present in the archive.
148 Normally only the member name is shown, but if the modifier O is
149 specified, then the corresponding offset of the member is also
150 displayed. Finally, in order to see the modes (permissions),
151 timestamp, owner, group, and size the v modifier should be
152 included.
153 If you do not specify a member, all files in the archive are
155 listed.
156 If there is more than one file with the same name (say, fie) in an
158 archive (say b.a), ar t b.a fie lists only the first instance; to
159 see them all, you must ask for a complete listing---in our example,
160 ar t b.a.
161 x Extract members (named member) from the archive. You can use the v
163 modifier with this operation, to request that ar list each name as
164 it extracts it.
165 If you do not specify a member, all files in the archive are
167 extracted.
168 Files cannot be extracted from a thin archive, and there are
170 restrictions on extracting from archives created with P: The paths
171 must not be absolute, may not contain "..", and any subdirectories
172 in the paths must exist. If it is desired to avoid these
173 restrictions then used the --output option to specify an output
174 directory.
175 A number of modifiers (mod) may immediately follow the p keyletter, to
177 specify variations on an operation's behavior:
178 a Add new files after an existing member of the archive. If you use
180 the modifier a, the name of an existing archive member must be
181 present as the relpos argument, before the archive specification.
182 b Add new files before an existing member of the archive. If you use
184 the modifier b, the name of an existing archive member must be
185 present as the relpos argument, before the archive specification.
186 (same as i).
187 c Create the archive. The specified archive is always created if it
189 did not exist, when you request an update. But a warning is issued
190 unless you specify in advance that you expect to create it, by
191 using this modifier.
192 D Operate in deterministic mode. When adding files and the archive
194 index use zero for UIDs, GIDs, timestamps, and use consistent file
195 modes for all files. When this option is used, if ar is used with
196 identical options and identical input files, multiple runs will
197 create identical output files regardless of the input files'
198 owners, groups, file modes, or modification times.
199 If binutils was configured with --enable-deterministic-archives,
201 then this mode is on by default. It can be disabled with the U
202 modifier, below.
203 f Truncate names in the archive. GNU ar will normally permit file
205 names of any length. This will cause it to create archives which
206 are not compatible with the native ar program on some systems. If
207 this is a concern, the f modifier may be used to truncate file
208 names when putting them in the archive.
209 i Insert new files before an existing member of the archive. If you
211 use the modifier i, the name of an existing archive member must be
212 present as the relpos argument, before the archive specification.
213 (same as b).
214 l Specify dependencies of this library. The dependencies must
216 immediately follow this option character, must use the same syntax
217 as the linker command line, and must be specified within a single
218 argument. I.e., if multiple items are needed, they must be quoted
219 to form a single command line argument. For example L
220 "-L/usr/local/lib -lmydep1 -lmydep2"
221 N Uses the count parameter. This is used if there are multiple
223 entries in the archive with the same name. Extract or delete
224 instance count of the given name from the archive.
225 o Preserve the original dates of members when extracting them. If
227 you do not specify this modifier, files extracted from the archive
228 are stamped with the time of extraction.
229 O Display member offsets inside the archive. Use together with the t
231 option.
232 P Use the full path name when matching or storing names in the
234 archive. Archives created with full path names are not POSIX
235 compliant, and thus may not work with tools other than up to date
236 GNU tools. Modifying such archives with GNU ar without using P
237 will remove the full path names unless the archive is a thin
238 archive. Note that P may be useful when adding files to a thin
239 archive since r without P ignores the path when choosing which
240 element to replace. Thus
241 ar rcST archive.a subdir/file1 subdir/file2 file1
243 will result in the first "subdir/file1" being replaced with "file1"
245 from the current directory. Adding P will prevent this
246 replacement.
247 s Write an object-file index into the archive, or update an existing
249 one, even if no other change is made to the archive. You may use
250 this modifier flag either with any operation, or alone. Running ar
251 s on an archive is equivalent to running ranlib on it.
252 S Do not generate an archive symbol table. This can speed up
254 building a large library in several steps. The resulting archive
255 can not be used with the linker. In order to build a symbol table,
256 you must omit the S modifier on the last execution of ar, or you
257 must run ranlib on the archive.
258 T Deprecated alias for --thin. T is not recommended because in many
260 ar implementations T has a different meaning, as specified by
261 X/Open System Interface.
262 u Normally, ar r... inserts all files listed into the archive. If
264 you would like to insert only those of the files you list that are
265 newer than existing members of the same names, use this modifier.
266 The u modifier is allowed only for the operation r (replace). In
267 particular, the combination qu is not allowed, since checking the
268 timestamps would lose any speed advantage from the operation q.
269 U Do not operate in deterministic mode. This is the inverse of the D
271 modifier, above: added files and the archive index will get their
272 actual UID, GID, timestamp, and file mode values.
273 This is the default unless binutils was configured with
275 --enable-deterministic-archives.
276 v This modifier requests the verbose version of an operation. Many
278 operations display additional information, such as filenames
279 processed, when the modifier v is appended.
280 V This modifier shows the version number of ar.
282 The ar program also supports some command-line options which are
284 neither modifiers nor actions, but which do change its behaviour in
285 specific ways:
286 --help
288 Displays the list of command-line options supported by ar and then
289 exits.
290 --version
292 Displays the version information of ar and then exits.
293 -X32_64
295 ar ignores an initial option spelled -X32_64, for compatibility
296 with AIX. The behaviour produced by this option is the default for
297 GNU ar. ar does not support any of the other -X options; in
298 particular, it does not support -X32 which is the default for AIX
299 ar.
300 --plugin name
302 The optional command-line switch --plugin name causes ar to load
303 the plugin called name which adds support for more file formats,
304 including object files with link-time optimization information.
305 This option is only available if the toolchain has been built with
307 plugin support enabled.
308 If --plugin is not provided, but plugin support has been enabled
310 then ar iterates over the files in ${libdir}/bfd-plugins in
311 alphabetic order and the first plugin that claims the object in
312 question is used.
313 Please note that this plugin search directory is not the one used
315 by ld's -plugin option. In order to make ar use the linker plugin
316 it must be copied into the ${libdir}/bfd-plugins directory. For
317 GCC based compilations the linker plugin is called
318 liblto_plugin.so.0.0.0. For Clang based compilations it is called
319 LLVMgold.so. The GCC plugin is always backwards compatible with
320 earlier versions, so it is sufficient to just copy the newest one.
321 --target target
323 The optional command-line switch --target bfdname specifies that
324 the archive members are in an object code format different from
325 your system's default format. See
326 --output dirname
328 The --output option can be used to specify a path to a directory
329 into which archive members should be extracted. If this option is
330 not specified then the current directory will be used.
331 Note - although the presence of this option does imply a x
333 extraction operation that option must still be included on the
334 command line.
335 --record-libdeps libdeps
337 The --record-libdeps option is identical to the l modifier, just
338 handled in long form.
339 --thin
341 Make the specified archive a thin archive. If it already exists
342 and is a regular archive, the existing members must be present in
343 the same directory as archive.
344 @file
346 Read command-line options from file. The options read are inserted
347 in place of the original @file option. If file does not exist, or
348 cannot be read, then the option will be treated literally, and not
349 removed.
350 Options in file are separated by whitespace. A whitespace
352 character may be included in an option by surrounding the entire
353 option in either single or double quotes. Any character (including
354 a backslash) may be included by prefixing the character to be
355 included with a backslash. The file may itself contain additional
356 @file options; any such options will be processed recursively.
357
359 nm(1), ranlib(1), and the Info entries for binutils.
360
362 Copyright (c) 1991-2022 Free Software Foundation, Inc.
363 Permission is granted to copy, distribute and/or modify this document
365 under the terms of the GNU Free Documentation License, Version 1.3 or
366 any later version published by the Free Software Foundation; with no
367 Invariant Sections, with no Front-Cover Texts, and with no Back-Cover
368 Texts. A copy of the license is included in the section entitled "GNU
369 Free Documentation License".
370binutils-2.38 2022-07-20 AR(1)