1pkg-config(1) General Commands Manual pkg-config(1)
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6 pkg-config - Return metainformation about installed libraries
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9 pkg-config [--modversion] [--help] [--print-errors] [--silence-errors]
10 [--cflags] [--libs] [--libs-only-L] [--libs-only-l] [--cflags-only-I]
11 [--variable=VARIABLENAME] [--define-variable=VARIABLENAME=VARIABLE‐
12 VALUE] [--uninstalled] [--exists] [--atleast-version=VERSION] [--exact-
13 version=VERSION] [--max-version=VERSION] [LIBRARIES...]
14
16 The pkg-config program is used to retrieve information about installed
17 libraries in the system. It is typically used to compile and link
18 against one or more libraries. Here is a typical usage scenario in a
19 Makefile:
20 program: program.c
22 cc program.c `pkg-config --cflags --libs gnomeui`
23 pkg-config retrieves information about packages from special metadata
25 files. These files are named after the package, with the extension .pc.
26 By default, pkg-config looks in the directory prefix/lib/pkgconfig for
27 these files; it will also look in the colon-separated (on Windows,
28 semicolon-separated) list of directories specified by the PKG_CON‐
29 FIG_PATH environment variable.
30 The package name specified on the pkg-config command line is defined to
33 be the name of the metadata file, minus the .pc extension. If a library
34 can install multiple versions simultaneously, it must give each version
35 its own name (for example, GTK 1.2 might have the package name "gtk+"
36 while GTK 2.0 has "gtk+-2.0").
37
40 The following options are supported:
41 --modversion
43 Requests that the version information of the libraries specified
44 on the command line be displayed. If pkg-config can find all
45 the libraries on the command line, each library's version string
46 is printed to stdout, one version per line. In this case pkg-
47 config exits successfully. If one or more libraries is unknown,
48 pkg-config exits with a nonzero code, and the contents of stdout
49 are undefined.
50 --help Displays a help message and terminates.
52 --print-errors
55 If one or more of the modules on the command line, or their
56 dependencies, are not found, or if an error occurs in parsing a
57 .pc file, then this option will cause errors explaining the
58 problem to be printed. With "predicate" options such as
59 "--exists" pkg-config runs silently by default, because it's
60 usually used in scripts that want to control what's output. This
61 option can be used alone (to just print errors encountered
62 locating modules on the command line) or with other options. The
63 PKG_CONFIG_DEBUG_SPEW environment variable overrides this
64 option.
65 --silence-errors
68 If one or more of the modules on the command line, or their
69 dependencies, are not found, or if an error occurs in parsing a
70 a .pc file, then this option will keep errors explaining the
71 problem from being printed. With "predicate" options such as
72 "--exists" pkg-config runs silently by default, because it's
73 usually used in scripts that want to control what's output. So
74 this option is only useful with options such as "--cflags" or
75 "--modversion" that print errors by default. The PKG_CON‐
76 FIG_DEBUG_SPEW environment variable overrides this option.
77 --errors-to-stdout
80 If printing errors, print them to stdout rather than the default
81 stderr
82 The following options are used to compile and link programs:
85 --cflags
87 This prints pre-processor and compile flags required to compile
88 the packages on the command line, including flags for all their
89 dependencies. Flags are "compressed" so that each identical flag
90 appears only once. pkg-config exits with a nonzero code if it
91 can't find metadata for one or more of the packages on the com‐
92 mand line.
93 --libs This option is identical to "--cflags", only it prints the link
95 flags. As with "--cflags", duplicate flags are merged (maintain‐
96 ing proper ordering), and flags for dependencies are included in
97 the output.
98 --libs-only-L
100 This prints the -L/-R part of "--libs". That is, it defines the
101 library search path but doesn't specify which libraries to link
102 with.
103 --libs-only-l
105 This prints the -l part of "--libs" for the libraries specified
106 on the command line. Note that the union of "--libs-only-l" and
107 "--libs-only-L" may be smaller than "--libs", due to flags such
108 as -rdynamic.
109 --variable=VARIABLENAME
112 This returns the value of a variable defined in a package's .pc
113 file. Most packages define the variable "prefix", for example,
114 so you can say:
115 $ pkg-config --variable=prefix glib-2.0
116 /usr/
117 --define-variable=VARIABLENAME=VARIABLEVALUE
119 This sets a global value for a variable, overriding the value in
120 any .pc files. Most packages define the variable "prefix", for
121 example, so you can say:
122 $ pkg-config --print-errors --define-variable=prefix=/foo \
123 --variable=prefix glib-2.0
124 /foo
125 --uninstalled
128 Normally if you request the package "foo" and the package "foo-
129 uninstalled" exists, pkg-config will prefer the "-uninstalled"
130 variant. This allows compilation/linking against uninstalled
131 packages. If you specify the "--uninstalled" option, pkg-config
132 will return successfully if any "-uninstalled" packages are
133 being used, and return failure (false) otherwise. (The
134 "PKG_CONFIG_DISABLE_UNINSTALLED" environment variable keeps pkg-
135 config from implicitly choosing "-uninstalled" packages, so if
136 that variable is set, they will only have been used if you pass
137 a name like "foo-uninstalled" on the command line explicitly.)
138 --exists
141 --atleast-version=VERSION
143 --exact-version=VERSION
145 --max-version=VERSION
147 These options test whether the package or list of packages on
148 the command line are known to pkg-config, and optionally whether
149 the version number of a package meets certain contraints. If
150 all packages exist and meet the specified version constraints,
151 pkg-config exits successfully. Otherwise it exits unsuccess‐
152 fully.
153 Rather than using the version-test options, you can simply give
155 a version constraint after each package name, for example:
156 $ pkg-config --exists 'glib-2.0 >= 1.3.4 libxml = 1.8.3'
157 Remember to use --print-errors if you want error messages.
158 --msvc-syntax
161 This option is available only on Windows. It causes pkg-config
162 to output -l and -L flags in the form recognized by the Micro‐
163 soft Visual C++ command-line compiler, cl. Specifically, instead
164 of -Lx:/some/path it prints /libpath:x/some/path, and instead of
165 -lfoo it prints foo.lib. Note that the --libs output consists of
166 flags for the linker, and should be placed on the cl command
167 line after a /link switch.
168 --dont-define-prefix
171 This option is available only on Windows. It prevents pkg-config
172 from automatically trying to override the value of the variable
173 "prefix" in each .pc file.
174 --prefix-variable=PREFIX
177 Also this option is available only on Windows. It sets the name
178 of the variable that pkg-config automatically sets as described
179 above.
180 --static
183 Output libraries suitable for static linking. That means
184 including any private libraries in the output. This relies on
185 proper tagging in the .pc files, else a too large number of
186 libraries will ordinarily be output.
187
190 PKG_CONFIG_PATH
191 A colon-separated (on Windows, semicolon-separated) list of
192 directories to search for .pc files. The default directory will
193 always be searched after searching the path; the default is lib‐
194 dir/pkgconfig:datadir/pkgconfig where libdir is the libdir where
195 pkg-config and datadir is the datadir where pkg-config was
196 installed.
197 PKG_CONFIG_DEBUG_SPEW
200 If set, causes pkg-config to print all kinds of debugging infor‐
201 mation and report all errors.
202 PKG_CONFIG_TOP_BUILD_DIR
205 A value to set for the magic variable pc_top_builddir which may
206 appear in .pc files. If the environment variable is not set, the
207 default value '$(top_builddir)' will be used. This variable
208 should refer to the top builddir of the Makefile where the com‐
209 pile/link flags reported by pkg-config will be used. This only
210 matters when compiling/linking against a package that hasn't yet
211 been installed.
212 PKG_CONFIG_DISABLE_UNINSTALLED
215 Normally if you request the package "foo" and the package "foo-
216 uninstalled" exists, pkg-config will prefer the "-uninstalled"
217 variant. This allows compilation/linking against uninstalled
218 packages. If this environment variable is set, it disables said
219 behavior.
220 PKG_CONFIG_ALLOW_SYSTEM_CFLAGS
223 Don't strip -I/usr/include out of cflags.
224 PKG_CONFIG_ALLOW_SYSTEM_LIBS
227 Don't strip -L/usr/lib out of libs
228 PKG_CONFIG_SYSROOT_DIR
231 Modify -I and -L to use the directories located in target sys‐
232 root. this option is usefull when crosscompiling package that
233 use pkg-config to determine CFLAGS anf LDFLAGS. -I and -L are
234 modified to point to the new system root. this means that a
235 -I/usr/include/libfoo will become -I/var/target/usr/include/lib‐
236 foo with a PKG_CONFIG_SYSROOT_DIR equal to /var/target (same
237 rule apply to -L)
238 PKG_CONFIG_LIBDIR
241 Replaces the default pkg-config search directory.
242
245 If a .pc file is found in a directory that matches the usual conven‐
246 tions (i.e., ends with \lib\pkgconfig), the prefix for that package is
247 assumed to be the grandparent of the directory where the file was
248 found, and the prefix variable is overridden for that file accordingly.
249 In addition to the PKG_CONFIG_PATH environment variable, the Registry
251 keys HKEY_CURRENT_USER\Software\pkgconfig\PKG_CONFIG_PATH and
252 HKEY_LOCAL_MACHINE\Software\pkgconfig\PKG_CONFIG_PATH can be used to
253 specify directories to search for .pc files. Each (string) value in
254 these keys is treated as a directory where to look for .pc files.
255
258 PKG_CHECK_MODULES(VARIABLE-PREFIX,MODULES[,ACTION-IF-FOUND,[ACTION-IF-
259 NOT-FOUND]])
260 The macro PKG_CHECK_MODULES can be used in configure.ac to check
262 whether modules exist. A typical usage would be:
263 PKG_CHECK_MODULES([MYSTUFF], [gtk+-2.0 >= 1.3.5 libxml = 1.8.4])
264 This would result in MYSTUFF_LIBS and MYSTUFF_CFLAGS substitu‐
266 tion variables, set to the libs and cflags for the given module
267 list. If a module is missing or has the wrong version, by
268 default configure will abort with a message. To replace the
269 default action, specify an ACTION-IF-NOT-FOUND. PKG_CHECK_MOD‐
270 ULES will not print any error messages if you specify your own
271 ACTION-IF-NOT-FOUND. However, it will set the variable
272 MYSTUFF_PKG_ERRORS, which you can use to display what went
273 wrong.
274 Note that if there is a possibility the first call to
276 PKG_CHECK_MODULES might not happen, you should be sure to
277 include an explicit call to PKG_PROG_PKG_CONFIG in your config‐
278 ure.ac
279 PKG_PROG_PKG_CONFIG([MIN-VERSION])
281 Defines the PKG_CONFIG variable to the best pkg-config avail‐
283 able, useful if you need pkg-config but don't want to use
284 PKG_CHECK_MODULES.
285 PKG_CHECK_EXISTS(MODULES, [ACTION-IF-FOUND], [ACTION-IF-NOT-
287 FOUND])
288 Check to see whether a particular set of modules exists. Simi‐
290 lar to PKG_CHECK_MODULES(), but does not set variables or print
291 errors.
292 Similar to PKG_CHECK_MODULES, make sure that the first instance
294 of this or PKG_CHECK_MODULES is called, or make sure to call
295 PKG_CHECK_EXISTS manually
296
299 To add a library to the set of packages pkg-config knows about, simply
300 install a .pc file. You should install this file to libdir/pkgconfig.
301 Here is an example file:
304 # This is a comment
305 prefix=/home/hp/unst # this defines a variable
306 exec_prefix=${prefix} # defining another variable in terms of the first
307 libdir=${exec_prefix}/lib
308 includedir=${prefix}/include
309 Name: GObject # human-readable name
311 Description: Object/type system for GLib # human-readable description
312 Version: 1.3.1
313 URL: http://www.gtk.org
314 Requires: glib-2.0 = 1.3.1
315 Conflicts: foobar <= 4.5
316 Libs: -L${libdir} -lgobject-1.3
317 Libs.private: -lm
318 Cflags: -I${includedir}/glib-2.0 -I${libdir}/glib/include
319 You would normally generate the file using configure, of course, so
322 that the prefix, etc. are set to the proper values.
323 Files have two kinds of line: keyword lines start with a keyword plus a
326 colon, and variable definitions start with an alphanumeric string plus
327 an equals sign. Keywords are defined in advance and have special mean‐
328 ing to pkg-config; variables do not, you can have any variables that
329 you wish (however, users may expect to retrieve the usual directory
330 name variables).
331 Note that variable references are written "${foo}"; you can escape lit‐
334 eral "${" as "$${".
335 Name: This field should be a human-readable name for the package. Note
338 that it is not the name passed as an argument to pkg-config.
339 Description:
341 This should be a brief description of the package
342 URL: An URL where people can get more information about and download
344 the package
345 Version:
347 This should be the most-specific-possible package version
348 string.
349 Requires:
351 This is a comma-separated list of packages that are required by
352 your package. Flags from dependent packages will be merged in to
353 the flags reported for your package. Optionally, you can specify
354 the version of the required package (using the operators =, <,
355 >, >=, <=); specifying a version allows pkg-config to perform
356 extra sanity checks. You may only mention the same package one
357 time on the Requires: line. If the version of a package is
358 unspecified, any version will be used with no checking.
359 Conflicts:
361 This optional line allows pkg-config to perform additional san‐
362 ity checks, primarily to detect broken user installations. The
363 syntax is the same as Requires: except that you can list the
364 same package more than once here, for example "foobar = 1.2.3,
365 foobar = 1.2.5, foobar >= 1.3", if you have reason to do so. If
366 a version isn't specified, then your package conflicts with all
367 versions of the mentioned package. If a user tries to use your
368 package and a conflicting package at the same time, then pkg-
369 config will complain.
370 Libs: This line should give the link flags specific to your package.
372 Don't add any flags for required packages; pkg-config will add
373 those automatically.
374 Libs.private:
377 This line should list any private libraries in use. Private
378 libraries are libraries which are not exposed through your
379 library, but are needed in the case of static linking.
380 Cflags:
383 This line should list the compile flags specific to your pack‐
384 age. Don't add any flags for required packages; pkg-config will
385 add those automatically.
386
389 pkg-config was written by James Henstridge, rewritten by Martijn van
390 Beers, and rewritten again by Havoc Pennington. Tim Janik, Owen Taylor,
391 and Raja Harinath submitted suggestions and some code. gnome-config
392 was written by Miguel de Icaza, Raja Harinath and various hackers in
393 the GNOME team. It was inspired by Owen Taylor's gtk-config program.
394
397 pkg-config does not handle mixing of parameters with and without =
398 well. Stick with one.
399 pkg-config(1)