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| <span id="command:unset"></span><h1>unset<a class="headerlink" href="#unset" title="Permalink to this headline">¶</a></h1> |
| <p>Unset a variable, cache variable, or environment variable.</p> |
| <div class="section" id="unset-normal-variable-or-cache-entry"> |
| <h2>Unset Normal Variable or Cache Entry<a class="headerlink" href="#unset-normal-variable-or-cache-entry" title="Permalink to this headline">¶</a></h2> |
| <div class="highlight-cmake notranslate"><div class="highlight"><pre><span></span><span class="nf">unset(</span><span class="nv"><variable></span><span class="w"> </span><span class="p">[</span><span class="no">CACHE</span><span class="w"> </span><span class="p">|</span><span class="w"> </span><span class="no">PARENT_SCOPE</span><span class="p">]</span><span class="nf">)</span><span class="w"></span> |
| </pre></div> |
| </div> |
| <p>Removes a normal variable from the current scope, causing it |
| to become undefined. If <code class="docutils literal notranslate"><span class="pre">CACHE</span></code> is present, then a cache variable |
| is removed instead of a normal variable. Note that when evaluating |
| <a class="reference internal" href="../manual/cmake-language.7.html#variable-references"><span class="std std-ref">Variable References</span></a> of the form <code class="docutils literal notranslate"><span class="pre">${VAR}</span></code>, CMake first searches |
| for a normal variable with that name. If no such normal variable exists, |
| CMake will then search for a cache entry with that name. Because of this |
| unsetting a normal variable can expose a cache variable that was previously |
| hidden. To force a variable reference of the form <code class="docutils literal notranslate"><span class="pre">${VAR}</span></code> to return an |
| empty string, use <code class="docutils literal notranslate"><span class="pre">set(<variable></span> <span class="pre">"")</span></code>, which clears the normal variable |
| but leaves it defined.</p> |
| <p>If <code class="docutils literal notranslate"><span class="pre">PARENT_SCOPE</span></code> is present then the variable is removed from the scope |
| above the current scope. See the same option in the <span class="target" id="index-0-command:set"></span><a class="reference internal" href="set.html#command:set" title="set"><code class="xref cmake cmake-command docutils literal notranslate"><span class="pre">set()</span></code></a> command |
| for further details.</p> |
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| <div class="section" id="unset-environment-variable"> |
| <h2>Unset Environment Variable<a class="headerlink" href="#unset-environment-variable" title="Permalink to this headline">¶</a></h2> |
| <div class="highlight-cmake notranslate"><div class="highlight"><pre><span></span><span class="nf">unset(</span><span class="o">ENV{</span><span class="nt"><variable></span><span class="o">}</span><span class="nf">)</span><span class="w"></span> |
| </pre></div> |
| </div> |
| <p>Removes <code class="docutils literal notranslate"><span class="pre"><variable></span></code> from the currently available |
| <span class="target" id="index-0-manual:cmake-env-variables(7)"></span><a class="reference internal" href="../manual/cmake-env-variables.7.html#manual:cmake-env-variables(7)" title="cmake-env-variables(7)"><code class="xref cmake cmake-manual docutils literal notranslate"><span class="pre">Environment</span> <span class="pre">Variables</span></code></a>. |
| Subsequent calls of <code class="docutils literal notranslate"><span class="pre">$ENV{<variable>}</span></code> will return the empty string.</p> |
| <p>This command affects only the current CMake process, not the process |
| from which CMake was called, nor the system environment at large, |
| nor the environment of subsequent build or test processes.</p> |
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| <li><a class="reference internal" href="#">unset</a><ul> |
| <li><a class="reference internal" href="#unset-normal-variable-or-cache-entry">Unset Normal Variable or Cache Entry</a></li> |
| <li><a class="reference internal" href="#unset-environment-variable">Unset Environment Variable</a></li> |
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