1pkg-config(1) General Commands Manual pkg-config(1)
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6 pkg-config - Return metainformation about installed libraries
7
9 pkg-config [--modversion] [--version] [--help] [--atleast-pkgconfig-
10 version=VERSION] [--print-errors] [--short-errors] [--silence-errors]
11 [--errors-to-stdout] [--debug] [--cflags] [--libs] [--libs-only-L]
12 [--libs-only-l] [--cflags-only-I] [--libs-only-other] [--cflags-only-
13 other] [--variable=VARIABLENAME] [--define-variable=VARIABLENAME=VARI‐
14 ABLEVALUE] [--print-variables] [--uninstalled] [--exists] [--atleast-
15 version=VERSION] [--exact-version=VERSION] [--max-version=VERSION]
16 [--list-all] [LIBRARIES...] [--print-provides] [--print-requires]
17 [--print-requires-private] [LIBRARIES...]
18
20 The pkg-config program is used to retrieve information about installed
21 libraries in the system. It is typically used to compile and link
22 against one or more libraries. Here is a typical usage scenario in a
23 Makefile:
24 program: program.c
26 cc program.c $(pkg-config --cflags --libs gnomeui)
27 pkg-config retrieves information about packages from special metadata
29 files. These files are named after the package, and has a .pc exten‐
30 sion. On most systems, pkg-config looks in /usr/lib/pkgconfig,
31 /usr/share/pkgconfig, /usr/local/lib/pkgconfig and
32 /usr/local/share/pkgconfig for these files. It will additionally look
33 in the colon-separated (on Windows, semicolon-separated) list of direc‐
34 tories specified by the PKG_CONFIG_PATH environment variable.
35 The package name specified on the pkg-config command line is defined to
37 be the name of the metadata file, minus the .pc extension. If a library
38 can install multiple versions simultaneously, it must give each version
39 its own name (for example, GTK 1.2 might have the package name "gtk+"
40 while GTK 2.0 has "gtk+-2.0").
41 In addition to specifying a package name on the command line, the full
43 path to a given .pc file may be given instead. This allows a user to
44 directly query a particular .pc file.
45
47 The following options are supported:
48 --modversion
50 Requests that the version information of the libraries specified
51 on the command line be displayed. If pkg-config can find all
52 the libraries on the command line, each library's version string
53 is printed to stdout, one version per line. In this case pkg-
54 config exits successfully. If one or more libraries is unknown,
55 pkg-config exits with a nonzero code, and the contents of stdout
56 are undefined.
57 --version
59 Displays the version of pkg-config and terminates.
60 --atleast-pkgconfig-version=VERSION
62 Requires at least the given version of pkg-config.
63 --help Displays a help message and terminates.
65 --print-errors
67 If one or more of the modules on the command line, or their
68 dependencies, are not found, or if an error occurs in parsing a
69 .pc file, then this option will cause errors explaining the
70 problem to be printed. With "predicate" options such as
71 "--exists" pkg-config runs silently by default, because it's
72 usually used in scripts that want to control what's output. This
73 option can be used alone (to just print errors encountered
74 locating modules on the command line) or with other options. The
75 PKG_CONFIG_DEBUG_SPEW environment variable overrides this
76 option.
77 --short-errors
79 Print short error messages.
80 --silence-errors
82 If one or more of the modules on the command line, or their
83 dependencies, are not found, or if an error occurs in parsing a
84 a .pc file, then this option will keep errors explaining the
85 problem from being printed. With "predicate" options such as
86 "--exists" pkg-config runs silently by default, because it's
87 usually used in scripts that want to control what's output. So
88 this option is only useful with options such as "--cflags" or
89 "--modversion" that print errors by default. The PKG_CON‐
90 FIG_DEBUG_SPEW environment variable overrides this option.
91 --errors-to-stdout
93 If printing errors, print them to stdout rather than the default
94 stderr
95 --debug
97 Print debugging information. This is slightly different than the
98 PKG_CONFIG_DEBUG_SPEW environment variable, which also enable
99 "--print-errors".
100 The following options are used to compile and link programs:
103 --cflags
105 This prints pre-processor and compile flags required to compile
106 the packages on the command line, including flags for all their
107 dependencies. Flags are "compressed" so that each identical flag
108 appears only once. pkg-config exits with a nonzero code if it
109 can't find metadata for one or more of the packages on the com‐
110 mand line.
111 --cflags-only-I
113 This prints the -I part of "--cflags". That is, it defines the
114 header search path but doesn't specify anything else.
115 --cflags-only-other
117 This prints parts of "--cflags" not covered by "--cflags-only-
118 I".
119 --libs This option is identical to "--cflags", only it prints the link
121 flags. As with "--cflags", duplicate flags are merged (maintain‐
122 ing proper ordering), and flags for dependencies are included in
123 the output.
124 --libs-only-L
126 This prints the -L/-R part of "--libs". That is, it defines the
127 library search path but doesn't specify which libraries to link
128 with.
129 --libs-only-l
131 This prints the -l part of "--libs" for the libraries specified
132 on the command line. Note that the union of "--libs-only-l" and
133 "--libs-only-L" may be smaller than "--libs", due to flags such
134 as -rdynamic.
135 --libs-only-other
137 This prints the parts of "--libs" not covered by "--libs-only-L"
138 and "--libs-only-l", such as "--pthread".
139 --variable=VARIABLENAME
141 This returns the value of a variable defined in a package's .pc
142 file. Most packages define the variable "prefix", for example,
143 so you can say:
144 $ pkg-config --variable=prefix glib-2.0
145 /usr/
146 --define-variable=VARIABLENAME=VARIABLEVALUE
148 This sets a global value for a variable, overriding the value in
149 any .pc files. Most packages define the variable "prefix", for
150 example, so you can say:
151 $ pkg-config --print-errors --define-variable=prefix=/foo \
152 --variable=prefix glib-2.0
153 /foo
154 --print-variables
156 Returns a list of all variables defined in the package.
157 --uninstalled
160 Normally if you request the package "foo" and the package "foo-
161 uninstalled" exists, pkg-config will prefer the "-uninstalled"
162 variant. This allows compilation/linking against uninstalled
163 packages. If you specify the "--uninstalled" option, pkg-config
164 will return successfully if any "-uninstalled" packages are
165 being used, and return failure (false) otherwise. (The PKG_CON‐
166 FIG_DISABLE_UNINSTALLED environment variable keeps pkg-config
167 from implicitly choosing "-uninstalled" packages, so if that
168 variable is set, they will only have been used if you pass a
169 name like "foo-uninstalled" on the command line explicitly.)
170 --exists
172 --atleast-version=VERSION
174 --exact-version=VERSION
176 --max-version=VERSION
178 These options test whether the package or list of packages on
179 the command line are known to pkg-config, and optionally whether
180 the version number of a package meets certain constraints. If
181 all packages exist and meet the specified version constraints,
182 pkg-config exits successfully. Otherwise it exits unsuccess‐
183 fully.
184 Rather than using the version-test options, you can simply give
186 a version constraint after each package name, for example:
187 $ pkg-config --exists 'glib-2.0 >= 1.3.4 libxml = 1.8.3'
188 Remember to use --print-errors if you want error messages.
189 --msvc-syntax
191 This option is available only on Windows. It causes pkg-config
192 to output -l and -L flags in the form recognized by the Micro‐
193 soft Visual C++ command-line compiler, cl. Specifically, instead
194 of -Lx:/some/path it prints /libpath:x/some/path, and instead of
195 -lfoo it prints foo.lib. Note that the --libs output consists of
196 flags for the linker, and should be placed on the cl command
197 line after a /link switch.
198 --dont-define-prefix
200 This option is available only on Windows. It prevents pkg-config
201 from automatically trying to override the value of the variable
202 "prefix" in each .pc file.
203 --prefix-variable=PREFIX
205 Also this option is available only on Windows. It sets the name
206 of the variable that pkg-config automatically sets as described
207 above.
208 --static
210 Output libraries suitable for static linking. That means
211 including any private libraries in the output. This relies on
212 proper tagging in the .pc files, else a too large number of
213 libraries will ordinarily be output.
214 --list-all
216 List all modules found in the pkg-config path.
217 --print-provides
219 List all modules the given packages provides.
220 --print-requires
222 List all modules the given packages requires.
223 --print-requires-private
225 List all modules the given packages requires for static linking
226 (see --static).
227
229 PKG_CONFIG_PATH
230 A colon-separated (on Windows, semicolon-separated) list of
231 directories to search for .pc files. The default directory will
232 always be searched after searching the path; the default is
233 libdir/pkgconfig:datadir/pkgconfig where libdir is the libdir
234 for pkg-config and datadir is the datadir for pkg-config when it
235 was installed.
236 PKG_CONFIG_DEBUG_SPEW
238 If set, causes pkg-config to print all kinds of debugging infor‐
239 mation and report all errors.
240 PKG_CONFIG_TOP_BUILD_DIR
242 A value to set for the magic variable pc_top_builddir which may
243 appear in .pc files. If the environment variable is not set, the
244 default value '$(top_builddir)' will be used. This variable
245 should refer to the top builddir of the Makefile where the com‐
246 pile/link flags reported by pkg-config will be used. This only
247 matters when compiling/linking against a package that hasn't yet
248 been installed.
249 PKG_CONFIG_DISABLE_UNINSTALLED
251 Normally if you request the package "foo" and the package "foo-
252 uninstalled" exists, pkg-config will prefer the "-uninstalled"
253 variant. This allows compilation/linking against uninstalled
254 packages. If this environment variable is set, it disables said
255 behavior.
256 PKG_CONFIG_ALLOW_SYSTEM_CFLAGS
258 Don't strip -I/usr/include out of cflags.
259 PKG_CONFIG_ALLOW_SYSTEM_LIBS
261 Don't strip -L/usr/lib out of libs
262 PKG_CONFIG_SYSROOT_DIR
264 Modify -I and -L to use the directories located in target sys‐
265 root. this option is useful when cross-compiling packages that
266 use pkg-config to determine CFLAGS and LDFLAGS. -I and -L are
267 modified to point to the new system root. this means that a
268 -I/usr/include/libfoo will become -I/var/target/usr/include/lib‐
269 foo with a PKG_CONFIG_SYSROOT_DIR equal to /var/target (same
270 rule apply to -L)
271 PKG_CONFIG_LIBDIR
273 Replaces the default pkg-config search directory, usually
274 /usr/lib/pkgconfig
275
277 pkg-config can be used to query itself for the default search path,
278 version number and other information, for instance using:
279 $ pkg-config --variable pc_path pkg-config
280 or
281 $ pkg-config --modversion pkg-config
282
284 If a .pc file is found in a directory that matches the usual conven‐
285 tions (i.e., ends with \lib\pkgconfig or \share\pkgconfig), the prefix
286 for that package is assumed to be the grandparent of the directory
287 where the file was found, and the prefix variable is overridden for
288 that file accordingly.
289 If the value of a variable in a .pc file begins with the original, non-
291 overridden, value of the prefix variable, then the overridden value of
292 prefix is used instead.
293
295 PKG_CHECK_MODULES(VARIABLE-PREFIX, MODULES [,ACTION-IF-FOUND [,ACTION-
296 IF-NOT-FOUND]])
297 The macro PKG_CHECK_MODULES can be used in configure.ac to check
299 whether modules exist. A typical usage would be:
300 PKG_CHECK_MODULES([MYSTUFF], [gtk+-2.0 >= 1.3.5 libxml = 1.8.4])
301 This would result in MYSTUFF_LIBS and MYSTUFF_CFLAGS substitu‐
303 tion variables, set to the libs and cflags for the given module
304 list. If a module is missing or has the wrong version, by
305 default configure will abort with a message. To replace the
306 default action, specify an ACTION-IF-NOT-FOUND.
307 PKG_CHECK_MODULES will not print any error messages if you spec‐
308 ify your own ACTION-IF-NOT-FOUND. However, it will set the
309 variable MYSTUFF_PKG_ERRORS, which you can use to display what
310 went wrong.
311 Note that if there is a possibility the first call to
313 PKG_CHECK_MODULES might not happen, you should be sure to
314 include an explicit call to PKG_PROG_PKG_CONFIG in your config‐
315 ure.ac.
316 Also note that repeated usage of VARIABLE-PREFIX is not recom‐
318 mended. After the first successful usage, subsequent calls with
319 the same VARIABLE-PREFIX will simply use the _LIBS and _CFLAGS
320 variables set from the previous usage without calling pkg-config
321 again.
322 PKG_PROG_PKG_CONFIG([MIN-VERSION])
324 Defines the PKG_CONFIG variable to the best pkg-config avail‐
326 able, useful if you need pkg-config but don't want to use
327 PKG_CHECK_MODULES.
328 PKG_CHECK_EXISTS(MODULES, [ACTION-IF-FOUND], [ACTION-IF-NOT-FOUND])
330 Check to see whether a particular set of modules exists. Simi‐
332 lar to PKG_CHECK_MODULES(), but does not set variables or print
333 errors.
334 Similar to PKG_CHECK_MODULES, make sure that the first instance
336 of this or PKG_CHECK_MODULES is called, or make sure to call
337 PKG_CHECK_EXISTS manually.
338
341 To add a library to the set of packages pkg-config knows about, simply
342 install a .pc file. You should install this file to libdir/pkgconfig.
343 Here is an example file:
345 # This is a comment
346 prefix=/home/hp/unst # this defines a variable
347 exec_prefix=${prefix} # defining another variable in terms of the first
348 libdir=${exec_prefix}/lib
349 includedir=${prefix}/include
350 Name: GObject # human-readable name
352 Description: Object/type system for GLib # human-readable description
353 Version: 1.3.1
354 URL: http://www.gtk.org
355 Requires: glib-2.0 = 1.3.1
356 Conflicts: foobar <= 4.5
357 Libs: -L${libdir} -lgobject-1.3
358 Libs.private: -lm
359 Cflags: -I${includedir}/glib-2.0 -I${libdir}/glib/include
360 You would normally generate the file using configure, so that the pre‐
362 fix, etc. are set to the proper values. The GNU Autoconf manual recom‐
363 mends generating files like .pc files at build time rather than config‐
364 ure time, so when you build the .pc file is a matter of taste and pref‐
365 erence.
366 Files have two kinds of line: keyword lines start with a keyword plus a
368 colon, and variable definitions start with an alphanumeric string plus
369 an equals sign. Keywords are defined in advance and have special mean‐
370 ing to pkg-config; variables do not, you can have any variables that
371 you wish (however, users may expect to retrieve the usual directory
372 name variables).
373 Note that variable references are written "${foo}"; you can escape lit‐
375 eral "${" as "$${".
376 Name: This field should be a human-readable name for the package. Note
378 that it is not the name passed as an argument to pkg-config.
379 Description:
381 This should be a brief description of the package
382 URL: An URL where people can get more information about and download
384 the package
385 Version:
387 This should be the most-specific-possible package version
388 string.
389 Requires:
391 This is a comma-separated list of packages that are required by
392 your package. Flags from dependent packages will be merged in to
393 the flags reported for your package. Optionally, you can specify
394 the version of the required package (using the operators =, <,
395 >, >=, <=); specifying a version allows pkg-config to perform
396 extra sanity checks. You may only mention the same package one
397 time on the Requires: line. If the version of a package is
398 unspecified, any version will be used with no checking.
399 Requires.private:
401 A list of packages required by this package. The difference from
402 Requires is that the packages listed under Requires.private are
403 not taken into account when a flag list is computed for dynami‐
404 cally linked executable (i.e., when --static was not specified).
405 In the situation where each .pc file corresponds to a library,
406 Requires.private shall be used exclusively to specify the depen‐
407 dencies between the libraries.
408 Conflicts:
410 This optional line allows pkg-config to perform additional san‐
411 ity checks, primarily to detect broken user installations. The
412 syntax is the same as Requires: except that you can list the
413 same package more than once here, for example "foobar = 1.2.3,
414 foobar = 1.2.5, foobar >= 1.3", if you have reason to do so. If
415 a version isn't specified, then your package conflicts with all
416 versions of the mentioned package. If a user tries to use your
417 package and a conflicting package at the same time, then pkg-
418 config will complain.
419 Libs: This line should give the link flags specific to your package.
421 Don't add any flags for required packages; pkg-config will add
422 those automatically.
423 Libs.private:
425 This line should list any private libraries in use. Private
426 libraries are libraries which are not exposed through your
427 library, but are needed in the case of static linking. This dif‐
428 fers from Requires.private in that it references libraries that
429 do not have package files installed.
430 Cflags:
432 This line should list the compile flags specific to your pack‐
433 age. Don't add any flags for required packages; pkg-config will
434 add those automatically.
435
437 pkg-config was written by James Henstridge, rewritten by Martijn van
438 Beers, and rewritten again by Havoc Pennington. Tim Janik, Owen Taylor,
439 and Raja Harinath submitted suggestions and some code. gnome-config
440 was written by Miguel de Icaza, Raja Harinath and various hackers in
441 the GNOME team. It was inspired by Owen Taylor's gtk-config program.
442
444 pkg-config does not handle mixing of parameters with and without =
445 well. Stick with one.
446 Bugs can be reported at http://bugs.freedesktop.org/ under the pkg-con‐
448 fig component.
449 pkg-config(1)