codeblocks-ep/help/html/programmerHelp/make/Libraries-Search.html at master · maifeeulasad/codeblocks-ep · GitHub

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Node:<a name="Libraries%2fSearch">Libraries/Search</a>,
Previous:<a rel="previous" accesskey="p" href="Implicit-Search.html#Implicit%2fSearch">Implicit/Search</a>,
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<h4 class="subsection">Directory Search for Link Libraries</h4>

   <p>Directory search applies in a special way to libraries used with the
linker.  This special feature comes into play when you write a prerequisite
whose name is of the form <code>-l</code><var>name</var><code></code>.  (You can tell something
strange is going on here because the prerequisite is normally the name of a
file, and the <em>file name</em> of a library generally looks like
<code>lib</code><var>name</var><code>.a</code>, not like <code>-l</code><var>name</var><code></code>.)

   <p>When a prerequisite's name has the form <code>-l</code><var>name</var><code></code>, <code>make</code>
handles it specially by searching for the file <code>lib</code><var>name</var><code>.so</code> in
the current directory, in directories specified by matching <code>vpath</code>
search paths and the <code>VPATH</code> search path, and then in the
directories <code>/lib</code>, <code>/usr/lib</code>, and <code></code><var>prefix</var><code>/lib</code>
(normally <code>/usr/local/lib</code>, but MS-DOS/MS-Windows versions of
<code>make</code> behave as if <var>prefix</var> is defined to be the root of the
DJGPP installation tree).

   <p>If that file is not found, then the file <code>lib</code><var>name</var><code>.a</code> is
searched for, in the same directories as above.

   <p>For example, if there is a <code>/usr/lib/libcurses.a</code> library on your
system (and no <code>/usr/lib/libcurses.so</code> file), then

<pre class="example">     foo : foo.c -lcurses
             cc $^ -o $@
     </pre>

<p>would cause the command <code>cc foo.c /usr/lib/libcurses.a -o foo</code> to
be executed when <code>foo</code> is older than <code>foo.c</code> or than
<code>/usr/lib/libcurses.a</code>.

   <p>Although the default set of files to be searched for is
<code>lib</code><var>name</var><code>.so</code> and <code>lib</code><var>name</var><code>.a</code>, this is customizable
via the <code>.LIBPATTERNS</code> variable.  Each word in the value of this
variable is a pattern string.  When a prerequisite like
<code>-l</code><var>name</var><code></code> is seen, <code>make</code> will replace the percent in
each pattern in the list with <var>name</var> and perform the above directory
searches using that library filename.  If no library is found, the next
word in the list will be used.

   <p>The default value for <code>.LIBPATTERNS</code> is "<code>lib%.so lib%.a</code>",
which provides the default behavior described above.

   <p>You can turn off link library expansion completely by setting this
variable to an empty value.

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