1Devel::CheckLib(3) User Contributed Perl Documentation Devel::CheckLib(3)
2
6 Devel::CheckLib - check that a library is available
7
9 Devel::CheckLib is a perl module that checks whether a particular C
10 library and its headers are available.
11
13 use Devel::CheckLib;
14 check_lib_or_exit( lib => 'jpeg', header => 'jpeglib.h' );
16 check_lib_or_exit( lib => [ 'iconv', 'jpeg' ] );
17 # or prompt for path to library and then do this:
19 check_lib_or_exit( lib => 'jpeg', libpath => $additional_path );
20
22 If you want to use this from Makefile.PL or Build.PL, do not simply
23 copy the module into your distribution as this may cause problems when
24 PAUSE and search.cpan.org index the distro. Instead, use the use-
25 devel-checklib script.
26
28 You pass named parameters to a function, describing to it how to build
29 and link to the libraries.
30 It works by trying to compile some code - which defaults to this:
32 int main(int argc, char *argv[]) { return 0; }
34 and linking it to the specified libraries. If something pops out the
36 end which looks executable, it gets executed, and if main() returns 0
37 we know that it worked. That tiny program is built once for each
38 library that you specify, and (without linking) once for each header
39 file.
40 If you want to check for the presence of particular functions in a
42 library, or even that those functions return particular results, then
43 you can pass your own function body for main() thus:
44 check_lib_or_exit(
46 function => 'foo();if(libversion() > 5) return 0; else return 1;'
47 incpath => ...
48 libpath => ...
49 lib => ...
50 header => ...
51 );
52 In that case, it will fail to build if either foo() or libversion()
54 don't exist, and main() will return the wrong value if libversion()'s
55 return value isn't what you want.
56
58 All of these take the same named parameters and are exported by
59 default. To avoid exporting them, "use Devel::CheckLib ()".
60 assert_lib
62 This takes several named parameters, all of which are optional, and
63 dies with an error message if any of the libraries listed can not be
64 found. Note: dying in a Makefile.PL or Build.PL may provoke a 'FAIL'
65 report from CPAN Testers' automated smoke testers. Use
66 "check_lib_or_exit" instead.
67 The named parameters are:
69 lib Must be either a string with the name of a single library or a
71 reference to an array of strings of library names. Depending on
72 the compiler found, library names will be fed to the compiler
73 either as "-l" arguments or as ".lib" file names. (E.g. "-ljpeg"
74 or "jpeg.lib")
75 libpath
77 a string or an array of strings representing additional paths to
78 search for libraries.
79 LIBS
81 a "ExtUtils::MakeMaker"-style space-separated list of libraries
82 (each preceded by '-l') and directories (preceded by '-L').
83 This can also be supplied on the command-line.
85 debug
87 If true - emit information during processing that can be used for
88 debugging.
89 And libraries are no use without header files, so ...
91 header
93 Must be either a string with the name of a single header file or a
94 reference to an array of strings of header file names.
95 incpath
97 a string or an array of strings representing additional paths to
98 search for headers.
99 INC a "ExtUtils::MakeMaker"-style space-separated list of incpaths,
101 each preceded by '-I'.
102 This can also be supplied on the command-line.
104 ccflags
106 Extra flags to pass to the compiler.
107 ldflags
109 Extra flags to pass to the linker.
110 analyze_binary
112 a callback function that will be invoked in order to perform custom
113 analysis of the generated binary. The callback arguments are the
114 library name and the path to the binary just compiled.
115 It is possible to use this callback, for instance, to inspect the
117 binary for further dependencies.
118 not_execute
120 Do not try to execute generated binary. Only check that compilation
121 has not failed.
122 check_lib_or_exit
124 This behaves exactly the same as "assert_lib()" except that instead of
125 dieing, it warns (with exactly the same error message) and exits. This
126 is intended for use in Makefile.PL / Build.PL when you might want to
127 prompt the user for various paths and things before checking that what
128 they've told you is sane.
129 If any library or header is missing, it exits with an exit value of 0
131 to avoid causing a CPAN Testers 'FAIL' report. CPAN Testers should
132 ignore this result -- which is what you want if an external library
133 dependency is not available.
134 check_lib
136 This behaves exactly the same as "assert_lib()" except that it is
137 silent, returning false instead of dieing, or true otherwise.
138
140 You must have a C compiler installed. We check for $Config{cc}, both
141 literally as it is in Config.pm and also in the $PATH.
142 It has been tested with varying degrees of rigorousness on:
144 gcc (on Linux, *BSD, Mac OS X, Solaris, Cygwin)
146 Sun's compiler tools on Solaris
147 IBM's tools on AIX
148 SGI's tools on Irix 6.5
149 Microsoft's tools on Windows
150 MinGW on Windows (with Strawberry Perl)
151 Borland's tools on Windows
152 QNX
153
155 This is a very early release intended primarily for feedback from
156 people who have discussed it. The interface may change and it has not
157 been adequately tested.
158 Feedback is most welcome, including constructive criticism. Bug
160 reports should be made using <http://rt.cpan.org/> or by email.
161 When submitting a bug report, please include the output from running:
163 perl -V
165 perl -MDevel::CheckLib -e0
166
168 Devel::CheckOS
169 Probe::Perl
171
173 David Cantrell <david@cantrell.org.uk>
174 David Golden <dagolden@cpan.org>
176 Yasuhiro Matsumoto <mattn@cpan.org>
178 Thanks to the cpan-testers-discuss mailing list for prompting us to
180 write it in the first place;
181 to Chris Williams for help with Borland support;
183 to Tony Cook for help with Microsoft compiler command-line options
185
187 Copyright 2007 David Cantrell. Portions copyright 2007 David Golden.
188 This module is free-as-in-speech software, and may be used,
190 distributed, and modified under the same conditions as perl itself.
191
193 This module is also free-as-in-mason software.
194perl v5.32.0 2020-07-28 Devel::CheckLib(3)