503 lines
56 KiB
HTML
503 lines
56 KiB
HTML
<!DOCTYPE html>
|
|
<html class="writer-html5" lang="en" >
|
|
<head>
|
|
<meta charset="utf-8" /><meta name="viewport" content="width=device-width, initial-scale=1" />
|
|
|
|
<meta name="viewport" content="width=device-width, initial-scale=1.0" />
|
|
<title>4.8.8. Writing a new command style — LAMMPS documentation</title>
|
|
<link rel="stylesheet" href="_static/pygments.css" type="text/css" />
|
|
<link rel="stylesheet" href="_static/css/theme.css" type="text/css" />
|
|
<link rel="stylesheet" href="_static/sphinx-design.min.css" type="text/css" />
|
|
<link rel="stylesheet" href="_static/css/lammps.css" type="text/css" />
|
|
<link rel="shortcut icon" href="_static/lammps.ico"/>
|
|
<link rel="canonical" href="https://docs.lammps.org/Developer_write_command.html" />
|
|
<!--[if lt IE 9]>
|
|
<script src="_static/js/html5shiv.min.js"></script>
|
|
<![endif]-->
|
|
|
|
<script src="_static/jquery.js?v=5d32c60e"></script>
|
|
<script src="_static/_sphinx_javascript_frameworks_compat.js?v=2cd50e6c"></script>
|
|
<script src="_static/documentation_options.js?v=5929fcd5"></script>
|
|
<script src="_static/doctools.js?v=9bcbadda"></script>
|
|
<script src="_static/sphinx_highlight.js?v=dc90522c"></script>
|
|
<script src="_static/design-tabs.js?v=f930bc37"></script>
|
|
<script async="async" src="_static/mathjax/es5/tex-mml-chtml.js?v=cadf963e"></script>
|
|
<script src="_static/js/theme.js"></script>
|
|
<link rel="index" title="Index" href="genindex.html" />
|
|
<link rel="search" title="Search" href="search.html" />
|
|
<link rel="next" title="4.9. Notes for developers and code maintainers" href="Developer_notes.html" />
|
|
<link rel="prev" title="4.8.7. Writing a new fix style" href="Developer_write_fix.html" />
|
|
</head>
|
|
|
|
<body class="wy-body-for-nav">
|
|
<div class="wy-grid-for-nav">
|
|
<nav data-toggle="wy-nav-shift" class="wy-nav-side">
|
|
<div class="wy-side-scroll">
|
|
<div class="wy-side-nav-search" >
|
|
|
|
|
|
|
|
<a href="Manual.html">
|
|
|
|
<img src="_static/lammps-logo.png" class="logo" alt="Logo"/>
|
|
</a>
|
|
<div class="lammps_version">Version: <b>19 Nov 2024</b></div>
|
|
<div class="lammps_release">git info: </div>
|
|
<div role="search">
|
|
<form id="rtd-search-form" class="wy-form" action="search.html" method="get">
|
|
<input type="text" name="q" placeholder="Search docs" aria-label="Search docs" />
|
|
<input type="hidden" name="check_keywords" value="yes" />
|
|
<input type="hidden" name="area" value="default" />
|
|
</form>
|
|
</div>
|
|
</div><div class="wy-menu wy-menu-vertical" data-spy="affix" role="navigation" aria-label="Navigation menu">
|
|
<p class="caption" role="heading"><span class="caption-text">User Guide</span></p>
|
|
<ul>
|
|
<li class="toctree-l1"><a class="reference internal" href="Intro.html">1. Introduction</a></li>
|
|
<li class="toctree-l1"><a class="reference internal" href="Install.html">2. Install LAMMPS</a></li>
|
|
<li class="toctree-l1"><a class="reference internal" href="Build.html">3. Build LAMMPS</a></li>
|
|
<li class="toctree-l1"><a class="reference internal" href="Run_head.html">4. Run LAMMPS</a></li>
|
|
<li class="toctree-l1"><a class="reference internal" href="Commands.html">5. Commands</a></li>
|
|
<li class="toctree-l1"><a class="reference internal" href="Packages.html">6. Optional packages</a></li>
|
|
<li class="toctree-l1"><a class="reference internal" href="Speed.html">7. Accelerate performance</a></li>
|
|
<li class="toctree-l1"><a class="reference internal" href="Howto.html">8. Howto discussions</a></li>
|
|
<li class="toctree-l1"><a class="reference internal" href="Examples.html">9. Example scripts</a></li>
|
|
<li class="toctree-l1"><a class="reference internal" href="Tools.html">10. Auxiliary tools</a></li>
|
|
<li class="toctree-l1"><a class="reference internal" href="Errors.html">11. Errors</a></li>
|
|
</ul>
|
|
<p class="caption" role="heading"><span class="caption-text">Programmer Guide</span></p>
|
|
<ul class="current">
|
|
<li class="toctree-l1"><a class="reference internal" href="Library.html">1. LAMMPS Library Interfaces</a></li>
|
|
<li class="toctree-l1"><a class="reference internal" href="Python_head.html">2. Use Python with LAMMPS</a></li>
|
|
<li class="toctree-l1"><a class="reference internal" href="Modify.html">3. Modifying & extending LAMMPS</a></li>
|
|
<li class="toctree-l1 current"><a class="reference internal" href="Developer.html">4. Information for Developers</a><ul class="current">
|
|
<li class="toctree-l2"><a class="reference internal" href="Developer_org.html">4.1. Source files</a></li>
|
|
<li class="toctree-l2"><a class="reference internal" href="Developer_org.html#class-topology">4.2. Class topology</a></li>
|
|
<li class="toctree-l2"><a class="reference internal" href="Developer_code_design.html">4.3. Code design</a></li>
|
|
<li class="toctree-l2"><a class="reference internal" href="Developer_parallel.html">4.4. Parallel algorithms</a></li>
|
|
<li class="toctree-l2"><a class="reference internal" href="Developer_atom.html">4.5. Accessing per-atom data</a></li>
|
|
<li class="toctree-l2"><a class="reference internal" href="Developer_comm_ops.html">4.6. Communication patterns</a></li>
|
|
<li class="toctree-l2"><a class="reference internal" href="Developer_flow.html">4.7. How a timestep works</a></li>
|
|
<li class="toctree-l2 current"><a class="reference internal" href="Developer_write.html">4.8. Writing new styles</a><ul class="current">
|
|
<li class="toctree-l3"><a class="reference internal" href="Developer_write_pair.html">4.8.1. Writing new pair styles</a></li>
|
|
<li class="toctree-l3"><a class="reference internal" href="Developer_write_pair.html#package-and-build-system-considerations">4.8.2. Package and build system considerations</a></li>
|
|
<li class="toctree-l3"><a class="reference internal" href="Developer_write_pair.html#case-1-a-pairwise-additive-model">4.8.3. Case 1: a pairwise additive model</a></li>
|
|
<li class="toctree-l3"><a class="reference internal" href="Developer_write_pair.html#case-2-a-many-body-potential">4.8.4. Case 2: a many-body potential</a></li>
|
|
<li class="toctree-l3"><a class="reference internal" href="Developer_write_pair.html#case-3-a-potential-requiring-communication">4.8.5. Case 3: a potential requiring communication</a></li>
|
|
<li class="toctree-l3"><a class="reference internal" href="Developer_write_pair.html#case-4-potentials-without-a-compute-function">4.8.6. Case 4: potentials without a compute() function</a></li>
|
|
<li class="toctree-l3"><a class="reference internal" href="Developer_write_fix.html">4.8.7. Writing a new fix style</a></li>
|
|
<li class="toctree-l3 current"><a class="current reference internal" href="#">4.8.8. Writing a new command style</a></li>
|
|
<li class="toctree-l3"><a class="reference internal" href="#case-1-implementing-the-geturl-command">4.8.9. Case 1: Implementing the geturl command</a></li>
|
|
</ul>
|
|
</li>
|
|
<li class="toctree-l2"><a class="reference internal" href="Developer_notes.html">4.9. Notes for developers and code maintainers</a></li>
|
|
<li class="toctree-l2"><a class="reference internal" href="Developer_updating.html">4.10. Notes for updating code written for older LAMMPS versions</a></li>
|
|
<li class="toctree-l2"><a class="reference internal" href="Developer_plugins.html">4.11. Writing plugins</a></li>
|
|
<li class="toctree-l2"><a class="reference internal" href="Developer_unittest.html">4.12. Adding tests for unit testing</a></li>
|
|
<li class="toctree-l2"><a class="reference internal" href="Classes.html">4.13. C++ base classes</a></li>
|
|
<li class="toctree-l2"><a class="reference internal" href="Developer_platform.html">4.14. Platform abstraction functions</a></li>
|
|
<li class="toctree-l2"><a class="reference internal" href="Developer_utils.html">4.15. Utility functions</a></li>
|
|
<li class="toctree-l2"><a class="reference internal" href="Developer_utils.html#special-math-functions">4.16. Special Math functions</a></li>
|
|
<li class="toctree-l2"><a class="reference internal" href="Developer_utils.html#tokenizer-classes">4.17. Tokenizer classes</a></li>
|
|
<li class="toctree-l2"><a class="reference internal" href="Developer_utils.html#argument-parsing-classes">4.18. Argument parsing classes</a></li>
|
|
<li class="toctree-l2"><a class="reference internal" href="Developer_utils.html#file-reader-classes">4.19. File reader classes</a></li>
|
|
<li class="toctree-l2"><a class="reference internal" href="Developer_utils.html#memory-pool-classes">4.20. Memory pool classes</a></li>
|
|
<li class="toctree-l2"><a class="reference internal" href="Developer_utils.html#eigensolver-functions">4.21. Eigensolver functions</a></li>
|
|
<li class="toctree-l2"><a class="reference internal" href="Developer_utils.html#communication-buffer-coding-with-ubuf">4.22. Communication buffer coding with <em>ubuf</em></a></li>
|
|
<li class="toctree-l2"><a class="reference internal" href="Developer_grid.html">4.23. Use of distributed grids within style classes</a></li>
|
|
</ul>
|
|
</li>
|
|
</ul>
|
|
<p class="caption" role="heading"><span class="caption-text">Command Reference</span></p>
|
|
<ul>
|
|
<li class="toctree-l1"><a class="reference internal" href="commands_list.html">Commands</a></li>
|
|
<li class="toctree-l1"><a class="reference internal" href="fixes.html">Fix Styles</a></li>
|
|
<li class="toctree-l1"><a class="reference internal" href="computes.html">Compute Styles</a></li>
|
|
<li class="toctree-l1"><a class="reference internal" href="pairs.html">Pair Styles</a></li>
|
|
<li class="toctree-l1"><a class="reference internal" href="bonds.html">Bond Styles</a></li>
|
|
<li class="toctree-l1"><a class="reference internal" href="angles.html">Angle Styles</a></li>
|
|
<li class="toctree-l1"><a class="reference internal" href="dihedrals.html">Dihedral Styles</a></li>
|
|
<li class="toctree-l1"><a class="reference internal" href="impropers.html">Improper Styles</a></li>
|
|
<li class="toctree-l1"><a class="reference internal" href="dumps.html">Dump Styles</a></li>
|
|
<li class="toctree-l1"><a class="reference internal" href="fix_modify_atc_commands.html">fix_modify AtC commands</a></li>
|
|
<li class="toctree-l1"><a class="reference internal" href="Bibliography.html">Bibliography</a></li>
|
|
</ul>
|
|
|
|
</div>
|
|
</div>
|
|
</nav>
|
|
|
|
<section data-toggle="wy-nav-shift" class="wy-nav-content-wrap"><nav class="wy-nav-top" aria-label="Mobile navigation menu" >
|
|
<i data-toggle="wy-nav-top" class="fa fa-bars"></i>
|
|
<a href="Manual.html">LAMMPS</a>
|
|
</nav>
|
|
|
|
<div class="wy-nav-content">
|
|
<div class="rst-content style-external-links">
|
|
<div role="navigation" aria-label="Page navigation">
|
|
<ul class="wy-breadcrumbs">
|
|
<li><a href="Manual.html" class="icon icon-home" aria-label="Home"></a></li>
|
|
<li class="breadcrumb-item"><a href="Developer.html"><span class="section-number">4. </span>Information for Developers</a></li>
|
|
<li class="breadcrumb-item"><a href="Developer_write.html"><span class="section-number">4.8. </span>Writing new styles</a></li>
|
|
<li class="breadcrumb-item active"><span class="section-number">4.8.8. </span>Writing a new command style</li>
|
|
<li class="wy-breadcrumbs-aside">
|
|
<a href="https://www.lammps.org"><img src="_static/lammps-logo.png" width="64" height="16" alt="LAMMPS Homepage"></a> | <a href="Commands_all.html">Commands</a>
|
|
</li>
|
|
</ul><div class="rst-breadcrumbs-buttons" role="navigation" aria-label="Sequential page navigation">
|
|
<a href="Developer_write_fix.html" class="btn btn-neutral float-left" title="4.8.7. Writing a new fix style" accesskey="p"><span class="fa fa-arrow-circle-left" aria-hidden="true"></span> Previous</a>
|
|
<a href="Developer_notes.html" class="btn btn-neutral float-right" title="4.9. Notes for developers and code maintainers" accesskey="n">Next <span class="fa fa-arrow-circle-right" aria-hidden="true"></span></a>
|
|
</div>
|
|
<hr/>
|
|
</div>
|
|
<div role="main" class="document" itemscope="itemscope" itemtype="http://schema.org/Article">
|
|
<div itemprop="articleBody">
|
|
|
|
<p><span class="math notranslate nohighlight">\(\renewcommand{\AA}{\text{Å}}\)</span></p>
|
|
<section id="writing-a-new-command-style">
|
|
<h1><span class="section-number">4.8.8. </span>Writing a new command style<a class="headerlink" href="#writing-a-new-command-style" title="Link to this heading"></a></h1>
|
|
<p>Command styles allow to do system manipulations or interfaces to the
|
|
operating system.</p>
|
|
<p>In the text below, we will discuss the implementation of one example. As
|
|
shown on the page for <a class="reference internal" href="Modify_command.html"><span class="doc">writing or extending command styles</span></a>, in order to implement a new command style, a new class
|
|
must be written that is either directly or indirectly derived from the
|
|
<code class="docutils literal notranslate"><span class="pre">Command</span></code> class. There is just one method that must be implemented:
|
|
<code class="docutils literal notranslate"><span class="pre">Command::command()</span></code>. In addition, a custom constructor is needed to get
|
|
access to the members of the <code class="docutils literal notranslate"><span class="pre">LAMMPS</span></code> class like the <code class="docutils literal notranslate"><span class="pre">Error</span></code> class to
|
|
print out error messages. The <code class="docutils literal notranslate"><span class="pre">Command::command()</span></code> method processes the
|
|
arguments passed to the command in the input and executes it. Any other
|
|
methods would be for the convenience of implementation of the new command.</p>
|
|
<p>In general, new command styles should be added to the <a class="reference internal" href="Packages_details.html#pkg-extra-command"><span class="std std-ref">EXTRA-COMMAND
|
|
package</span></a>. If you feel that your contribution should be
|
|
added to a different package, please consult with the <a class="reference internal" href="Intro_authors.html"><span class="doc">LAMMPS
|
|
developers</span></a> first. The contributed code needs to support
|
|
the <a class="reference internal" href="Build_make.html"><span class="doc">traditional GNU make build process</span></a> <strong>and</strong> the
|
|
<a class="reference internal" href="Build_cmake.html"><span class="doc">CMake build process</span></a>.</p>
|
|
</section>
|
|
<hr class="docutils" />
|
|
<section id="case-1-implementing-the-geturl-command">
|
|
<h1><span class="section-number">4.8.9. </span>Case 1: Implementing the geturl command<a class="headerlink" href="#case-1-implementing-the-geturl-command" title="Link to this heading"></a></h1>
|
|
<p>In this section, we will describe the procedure of adding a simple command
|
|
style to LAMMPS: the <a class="reference internal" href="geturl.html"><span class="doc">geturl command</span></a> that allows to download
|
|
files directly without having to rely on an external program like “wget” or
|
|
“curl”. The complete implementation can be found in the files
|
|
<code class="docutils literal notranslate"><span class="pre">src/EXTRA-COMMAND/geturl.cpp</span></code> and <code class="docutils literal notranslate"><span class="pre">src/EXTRA-COMMAND/geturl.h</span></code> of the
|
|
LAMMPS source code.</p>
|
|
<section id="interfacing-the-libcurl-library">
|
|
<h2>Interfacing the <em>libcurl</em> library<a class="headerlink" href="#interfacing-the-libcurl-library" title="Link to this heading"></a></h2>
|
|
<p>Rather than implementing the various protocols for downloading files, we
|
|
rely on an external library: <a class="reference external" href="https:://curl.se/libcurl/">libcurl library</a>.
|
|
This requires that the library and its headers are installed. For the
|
|
traditional GNU make build system, this simply requires edits to the machine
|
|
makefile to add compilation flags like for other libraries. For the CMake
|
|
based build system, we need to add some lines to the file
|
|
<code class="docutils literal notranslate"><span class="pre">cmake/Modules/Packages/EXTRA-COMMAND.cmake</span></code>:</p>
|
|
<div class="highlight-cmake notranslate"><div class="highlight"><pre><span></span><span class="nb">find_package</span><span class="p">(</span><span class="s">CURL</span><span class="w"> </span><span class="s">QUIET</span><span class="w"> </span><span class="s">COMPONENTS</span><span class="w"> </span><span class="s">HTTP</span><span class="w"> </span><span class="s">HTTPS</span><span class="p">)</span>
|
|
<span class="nb">option</span><span class="p">(</span><span class="s">WITH_CURL</span><span class="w"> </span><span class="s2">"Enable libcurl support"</span><span class="w"> </span><span class="o">${</span><span class="nv">CURL_FOUND</span><span class="o">}</span><span class="p">)</span>
|
|
<span class="nb">if</span><span class="p">(</span><span class="s">WITH_CURL</span><span class="p">)</span>
|
|
<span class="w"> </span><span class="nb">find_package</span><span class="p">(</span><span class="s">CURL</span><span class="w"> </span><span class="s">REQUIRED</span><span class="w"> </span><span class="s">COMPONENTS</span><span class="w"> </span><span class="s">HTTP</span><span class="w"> </span><span class="s">HTTPS</span><span class="p">)</span>
|
|
<span class="w"> </span><span class="nb">target_compile_definitions</span><span class="p">(</span><span class="s">lammps</span><span class="w"> </span><span class="s">PRIVATE</span><span class="w"> </span><span class="s">-DLAMMPS_CURL</span><span class="p">)</span>
|
|
<span class="w"> </span><span class="nb">target_link_libraries</span><span class="p">(</span><span class="s">lammps</span><span class="w"> </span><span class="s">PRIVATE</span><span class="w"> </span><span class="s">CURL::libcurl</span><span class="p">)</span>
|
|
<span class="nb">endif</span><span class="p">()</span>
|
|
</pre></div>
|
|
</div>
|
|
<p>The first <code class="docutils literal notranslate"><span class="pre">find_package()</span></code> command uses a built-in CMake module to find
|
|
an existing <em>libcurl</em> installation with development headers and support for
|
|
using the HTTP and HTTPS protocols. The “QUIET” flag ensures that there is
|
|
no screen output and no error if the search fails. The status of the search
|
|
is recorded in the “${CURL_FOUND}” variable. That variable sets the default
|
|
of the WITH_CURL option, which toggles whether support for <em>libcurl</em> is included
|
|
or not.</p>
|
|
<p>The second <code class="docutils literal notranslate"><span class="pre">find_package()</span></code> uses the “REQUIRED” flag to produce an error
|
|
if the WITH_CURL option was set to <code class="docutils literal notranslate"><span class="pre">True</span></code>, but no suitable <em>libcurl</em>
|
|
implementation with development support was found. This construct is used
|
|
so that the CMake script code inside the <code class="docutils literal notranslate"><span class="pre">if(WITH_CURL)</span></code> and <code class="docutils literal notranslate"><span class="pre">endif()</span></code>
|
|
block can be expanded later to download and compile <em>libcurl</em> as part of the
|
|
LAMMPS build process, if it is not found locally. The
|
|
<code class="docutils literal notranslate"><span class="pre">target_compile_definitions()</span></code> function added the define <code class="docutils literal notranslate"><span class="pre">-DLAMMPS_CURL</span></code>
|
|
to the compilation flags when compiling objects for the LAMMPS library.
|
|
This allows to always compile the <a class="reference internal" href="geturl.html"><span class="doc">geturl command</span></a>, but use
|
|
pre-processing to compile in the interface to <em>libcurl</em> only when it is
|
|
present and usable and otherwise stop with an error message about the
|
|
unavailability of <em>libcurl</em> to execute the functionality of the command.</p>
|
|
</section>
|
|
<section id="header-file">
|
|
<h2>Header file<a class="headerlink" href="#header-file" title="Link to this heading"></a></h2>
|
|
<p>The first segment of any LAMMPS source should be the copyright and
|
|
license statement. Note the marker in the first line to indicate to
|
|
editors like emacs that this file is a C++ source, even though the .h
|
|
extension suggests a C source (this is a convention inherited from the
|
|
very beginning of the C++ version of LAMMPS).</p>
|
|
<div class="highlight-c++ notranslate"><div class="highlight"><pre><span></span><span class="cm">/* -*- c++ -*- ----------------------------------------------------------</span>
|
|
<span class="cm"> LAMMPS - Large-scale Atomic/Molecular Massively Parallel Simulator</span>
|
|
<span class="cm"> https://www.lammps.org/, Sandia National Laboratories</span>
|
|
<span class="cm"> LAMMPS development team: developers@lammps.org</span>
|
|
|
|
<span class="cm"> Copyright (2003) Sandia Corporation. Under the terms of Contract</span>
|
|
<span class="cm"> DE-AC04-94AL85000 with Sandia Corporation, the U.S. Government retains</span>
|
|
<span class="cm"> certain rights in this software. This software is distributed under</span>
|
|
<span class="cm"> the GNU General Public License.</span>
|
|
|
|
<span class="cm"> See the README file in the top-level LAMMPS directory.</span>
|
|
<span class="cm">------------------------------------------------------------------------- */</span>
|
|
</pre></div>
|
|
</div>
|
|
<p>Every command style must be registered in LAMMPS by including the following
|
|
lines of code in the second part of the header after the copyright
|
|
message and before the include guards for the class definition:</p>
|
|
<div class="highlight-c++ notranslate"><div class="highlight"><pre><span></span><span class="cp">#ifdef COMMAND_CLASS</span>
|
|
<span class="c1">// clang-format off</span>
|
|
<span class="n">CommandStyle</span><span class="p">(</span><span class="n">geturl</span><span class="p">,</span><span class="n">GetURL</span><span class="p">);</span>
|
|
<span class="c1">// clang-format on</span>
|
|
<span class="cp">#else</span>
|
|
</pre></div>
|
|
</div>
|
|
<p>This block between <code class="docutils literal notranslate"><span class="pre">#ifdef</span> <span class="pre">COMMAND_CLASS</span></code> and <code class="docutils literal notranslate"><span class="pre">#else</span></code> will be
|
|
included by the <code class="docutils literal notranslate"><span class="pre">Input</span></code> class in <code class="docutils literal notranslate"><span class="pre">input.cpp</span></code> to build a map of
|
|
“factory functions” that will create an instance of a Command class
|
|
and call its <code class="docutils literal notranslate"><span class="pre">command()</span></code> method. The map connects the name of the
|
|
command <code class="docutils literal notranslate"><span class="pre">geturl</span></code> with the name of the class <code class="docutils literal notranslate"><span class="pre">GetURL</span></code>. During
|
|
compilation, LAMMPS constructs a file <code class="docutils literal notranslate"><span class="pre">style_command.h</span></code> that contains
|
|
<code class="docutils literal notranslate"><span class="pre">#include</span></code> statements for all “installed” command styles. Before
|
|
including <code class="docutils literal notranslate"><span class="pre">style_command.h</span></code> into <code class="docutils literal notranslate"><span class="pre">input.cpp</span></code>, the <code class="docutils literal notranslate"><span class="pre">COMMAND_CLASS</span></code>
|
|
define is set and the <code class="docutils literal notranslate"><span class="pre">CommandStyle(name,class)</span></code> macro defined. The
|
|
code of the macro adds the installed command styles to the “factory map”
|
|
which enables the <code class="docutils literal notranslate"><span class="pre">Input</span></code> to execute the command.</p>
|
|
<p>The list of header files to include in <code class="docutils literal notranslate"><span class="pre">style_command.h</span></code> is automatically
|
|
updated by the build system if there are new files, so the presence of the
|
|
new header file in the <code class="docutils literal notranslate"><span class="pre">src/EXTRA-COMMAND</span></code> folder and the enabling of the
|
|
EXTRA-COMMAND package will trigger LAMMPS to include the new command style
|
|
when it is (re-)compiled. The “// clang-format” format comments are needed
|
|
so that running <a class="reference internal" href="Build_development.html#clang-format"><span class="std std-ref">clang-format</span></a> on the file will not
|
|
insert unwanted blanks which would break the <code class="docutils literal notranslate"><span class="pre">CommandStyle</span></code> macro.</p>
|
|
<p>The third part of the header file is the actual class definition of the
|
|
<code class="docutils literal notranslate"><span class="pre">GetURL</span></code> class. This has the custom constructor and the <code class="docutils literal notranslate"><span class="pre">command()</span></code>
|
|
method implemented by this command style. For the constructor there is
|
|
nothing to do but to pass the <code class="docutils literal notranslate"><span class="pre">lmp</span></code> pointer to the base class. Since the
|
|
<code class="docutils literal notranslate"><span class="pre">command()</span></code> method is labeled “virtual” in the base class, it must be
|
|
given the “override” property.</p>
|
|
<div class="highlight-c++ notranslate"><div class="highlight"><pre><span></span><span class="cp">#ifndef LMP_GETURL_H</span>
|
|
<span class="cp">#define LMP_GETURL_H</span>
|
|
|
|
<span class="cp">#include</span><span class="w"> </span><span class="cpf">"command.h"</span>
|
|
|
|
<span class="k">namespace</span><span class="w"> </span><span class="nn">LAMMPS_NS</span><span class="w"> </span><span class="p">{</span>
|
|
|
|
<span class="k">class</span><span class="w"> </span><span class="nc">GetURL</span><span class="w"> </span><span class="o">:</span><span class="w"> </span><span class="k">public</span><span class="w"> </span><span class="n">Command</span><span class="w"> </span><span class="p">{</span>
|
|
<span class="w"> </span><span class="k">public</span><span class="o">:</span>
|
|
<span class="w"> </span><span class="n">GetURL</span><span class="p">(</span><span class="k">class</span><span class="w"> </span><span class="nc">LAMMPS</span><span class="w"> </span><span class="o">*</span><span class="n">lmp</span><span class="p">)</span><span class="w"> </span><span class="o">:</span><span class="w"> </span><span class="n">Command</span><span class="p">(</span><span class="n">lmp</span><span class="p">)</span><span class="w"> </span><span class="p">{};</span>
|
|
<span class="w"> </span><span class="kt">void</span><span class="w"> </span><span class="nf">command</span><span class="p">(</span><span class="kt">int</span><span class="p">,</span><span class="w"> </span><span class="kt">char</span><span class="w"> </span><span class="o">**</span><span class="p">)</span><span class="w"> </span><span class="k">override</span><span class="p">;</span>
|
|
<span class="p">};</span>
|
|
<span class="p">}</span><span class="w"> </span><span class="c1">// namespace LAMMPS_NS</span>
|
|
<span class="cp">#endif</span>
|
|
<span class="cp">#endif</span>
|
|
</pre></div>
|
|
</div>
|
|
<p>The “override” property helps to detect unexpected mismatches because
|
|
compilation will stop with an error in case the signature of a function
|
|
is changed in the base class without also changing it in all derived
|
|
classes.</p>
|
|
</section>
|
|
<section id="implementation-file">
|
|
<h2>Implementation file<a class="headerlink" href="#implementation-file" title="Link to this heading"></a></h2>
|
|
<p>We move on to the implementation of the <code class="docutils literal notranslate"><span class="pre">GetURL</span></code> class in the
|
|
<code class="docutils literal notranslate"><span class="pre">geturl.cpp</span></code> file. This file also starts with a LAMMPS copyright and
|
|
license header. Below that notice is typically the space where comments may
|
|
be added with additional information about this specific file, the
|
|
author(s), affiliation(s), and email address(es). This way the contributing
|
|
author(s) can be easily contacted, when there are questions about the
|
|
implementation later. Since the file(s) may be around for a long time, it
|
|
is beneficial to use some kind of “permanent” email address, if possible.</p>
|
|
<div class="highlight-c++ notranslate"><div class="highlight"><pre><span></span><span class="cm">/* ----------------------------------------------------------------------</span>
|
|
<span class="cm"> LAMMPS - Large-scale Atomic/Molecular Massively Parallel Simulator</span>
|
|
<span class="cm"> https://www.lammps.org/, Sandia National Laboratories</span>
|
|
<span class="cm"> LAMMPS development team: developers@lammps.org</span>
|
|
|
|
<span class="cm"> Copyright (2003) Sandia Corporation. Under the terms of Contract</span>
|
|
<span class="cm"> DE-AC04-94AL85000 with Sandia Corporation, the U.S. Government retains</span>
|
|
<span class="cm"> certain rights in this software. This software is distributed under</span>
|
|
<span class="cm"> the GNU General Public License.</span>
|
|
|
|
<span class="cm"> See the README file in the top-level LAMMPS directory.</span>
|
|
<span class="cm">------------------------------------------------------------------------- */</span>
|
|
|
|
<span class="cm">/* ----------------------------------------------------------------------</span>
|
|
<span class="cm"> Contributing authors: Axel Kohlmeyer (Temple U),</span>
|
|
<span class="cm">------------------------------------------------------------------------- */</span>
|
|
|
|
<span class="cp">#include</span><span class="w"> </span><span class="cpf">"geturl.h"</span>
|
|
|
|
<span class="cp">#include</span><span class="w"> </span><span class="cpf">"comm.h"</span>
|
|
<span class="cp">#include</span><span class="w"> </span><span class="cpf">"error.h"</span>
|
|
|
|
<span class="cp">#if defined(LAMMPS_CURL)</span>
|
|
<span class="cp">#include</span><span class="w"> </span><span class="cpf"><curl/curl.h></span>
|
|
<span class="cp">#endif</span>
|
|
|
|
<span class="k">using</span><span class="w"> </span><span class="k">namespace</span><span class="w"> </span><span class="nn">LAMMPS_NS</span><span class="p">;</span>
|
|
</pre></div>
|
|
</div>
|
|
<p>The second section of the implementation file has various include
|
|
statements. The include file for the class header has to come first, then a
|
|
couple of LAMMPS classes (sorted alphabetically) followed by the header for
|
|
the <em>libcurl</em> interface. This is wrapped into an <code class="docutils literal notranslate"><span class="pre">#ifdef</span></code> block so that
|
|
LAMMPS will compile this file without error when the <em>libcurl</em> header is not
|
|
available and thus the define not set. The final statement of this segment
|
|
imports the <code class="docutils literal notranslate"><span class="pre">LAMMPS_NS::</span></code> namespace globally for this file. This way, all
|
|
LAMMPS specific functions and classes do not have to be prefixed with
|
|
<code class="docutils literal notranslate"><span class="pre">LAMMPS_NS::</span></code>.</p>
|
|
</section>
|
|
<section id="the-command-function-required">
|
|
<h2>The command() function (required)<a class="headerlink" href="#the-command-function-required" title="Link to this heading"></a></h2>
|
|
<p>Since the required custom constructor is trivial and implemented in the
|
|
header, there is only one function that must be implemented for a command
|
|
style and that is the <code class="docutils literal notranslate"><span class="pre">command()</span></code> function.</p>
|
|
<div class="highlight-c++ notranslate"><div class="highlight"><pre><span></span><span class="kt">void</span><span class="w"> </span><span class="nf">GetURL::command</span><span class="p">(</span><span class="kt">int</span><span class="w"> </span><span class="n">narg</span><span class="p">,</span><span class="w"> </span><span class="kt">char</span><span class="w"> </span><span class="o">**</span><span class="n">arg</span><span class="p">)</span>
|
|
<span class="p">{</span>
|
|
<span class="cp">#if !defined(LAMMPS_CURL)</span>
|
|
<span class="w"> </span><span class="n">error</span><span class="o">-></span><span class="n">all</span><span class="p">(</span><span class="n">FLERR</span><span class="p">,</span><span class="w"> </span><span class="s">"LAMMPS has not been compiled with libcurl support"</span><span class="p">);</span>
|
|
<span class="cp">#else</span>
|
|
<span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">narg</span><span class="w"> </span><span class="o"><</span><span class="w"> </span><span class="mi">1</span><span class="p">)</span><span class="w"> </span><span class="n">utils</span><span class="o">::</span><span class="n">missing_cmd_args</span><span class="p">(</span><span class="n">FLERR</span><span class="p">,</span><span class="w"> </span><span class="s">"geturl"</span><span class="p">,</span><span class="w"> </span><span class="n">error</span><span class="p">);</span>
|
|
<span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="n">verify</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="mi">1</span><span class="p">;</span>
|
|
<span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="n">overwrite</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="mi">1</span><span class="p">;</span>
|
|
<span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="n">verbose</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="mi">0</span><span class="p">;</span>
|
|
</pre></div>
|
|
</div>
|
|
<p>This first part also has the <code class="docutils literal notranslate"><span class="pre">#ifdef</span></code> block depending on the LAMMPS_CURL
|
|
define. This way the command will simply print an error, if <em>libcurl</em> is
|
|
not available but will not fail to compile. Furthermore, it sets the
|
|
defaults for the following optional arguments.</p>
|
|
<div class="highlight-c++ notranslate"><div class="highlight"><pre><span></span><span class="c1">// process arguments</span>
|
|
|
|
<span class="n">std</span><span class="o">::</span><span class="n">string</span><span class="w"> </span><span class="n">url</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">arg</span><span class="p">[</span><span class="mi">0</span><span class="p">];</span>
|
|
|
|
<span class="c1">// sanity check</span>
|
|
|
|
<span class="k">if</span><span class="w"> </span><span class="p">((</span><span class="n">url</span><span class="p">.</span><span class="n">find</span><span class="p">(</span><span class="sc">':'</span><span class="p">)</span><span class="w"> </span><span class="o">==</span><span class="w"> </span><span class="n">std</span><span class="o">::</span><span class="n">string</span><span class="o">::</span><span class="n">npos</span><span class="p">)</span><span class="w"> </span><span class="o">||</span><span class="w"> </span><span class="p">(</span><span class="n">url</span><span class="p">.</span><span class="n">find</span><span class="p">(</span><span class="sc">'/'</span><span class="p">)</span><span class="w"> </span><span class="o">==</span><span class="w"> </span><span class="n">std</span><span class="o">::</span><span class="n">string</span><span class="o">::</span><span class="n">npos</span><span class="p">))</span>
|
|
<span class="w"> </span><span class="n">error</span><span class="o">-></span><span class="n">all</span><span class="p">(</span><span class="n">FLERR</span><span class="p">,</span><span class="w"> </span><span class="s">"URL '{}' is not a supported URL"</span><span class="p">,</span><span class="w"> </span><span class="n">url</span><span class="p">);</span>
|
|
|
|
<span class="n">std</span><span class="o">::</span><span class="n">string</span><span class="w"> </span><span class="n">output</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">url</span><span class="p">.</span><span class="n">substr</span><span class="p">(</span><span class="n">url</span><span class="p">.</span><span class="n">find_last_of</span><span class="p">(</span><span class="sc">'/'</span><span class="p">)</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="mi">1</span><span class="p">);</span>
|
|
<span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">output</span><span class="p">.</span><span class="n">empty</span><span class="p">())</span><span class="w"> </span><span class="n">error</span><span class="o">-></span><span class="n">all</span><span class="p">(</span><span class="n">FLERR</span><span class="p">,</span><span class="w"> </span><span class="s">"URL '{}' must end in a file string"</span><span class="p">,</span><span class="w"> </span><span class="n">url</span><span class="p">);</span>
|
|
</pre></div>
|
|
</div>
|
|
<p>This block stores the positional, i.e. non-optional argument of the URL to
|
|
be downloaded and adds a couple of sanity checks on the string to make sure it is
|
|
a valid URL. Also it derives the default name of the output file from the URL.</p>
|
|
<div class="highlight-c++ notranslate"><div class="highlight"><pre><span></span><span class="kt">int</span><span class="w"> </span><span class="n">iarg</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="mi">1</span><span class="p">;</span>
|
|
<span class="k">while</span><span class="w"> </span><span class="p">(</span><span class="n">iarg</span><span class="w"> </span><span class="o"><</span><span class="w"> </span><span class="n">narg</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
|
|
<span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">strcmp</span><span class="p">(</span><span class="n">arg</span><span class="p">[</span><span class="n">iarg</span><span class="p">],</span><span class="w"> </span><span class="s">"output"</span><span class="p">)</span><span class="w"> </span><span class="o">==</span><span class="w"> </span><span class="mi">0</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
|
|
<span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">iarg</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="mi">2</span><span class="w"> </span><span class="o">></span><span class="w"> </span><span class="n">narg</span><span class="p">)</span><span class="w"> </span><span class="n">utils</span><span class="o">::</span><span class="n">missing_cmd_args</span><span class="p">(</span><span class="n">FLERR</span><span class="p">,</span><span class="w"> </span><span class="s">"geturl output"</span><span class="p">,</span><span class="w"> </span><span class="n">error</span><span class="p">);</span>
|
|
<span class="w"> </span><span class="n">output</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">arg</span><span class="p">[</span><span class="n">iarg</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="mi">1</span><span class="p">];</span>
|
|
<span class="w"> </span><span class="o">++</span><span class="n">iarg</span><span class="p">;</span>
|
|
<span class="w"> </span><span class="p">}</span><span class="w"> </span><span class="k">else</span><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">strcmp</span><span class="p">(</span><span class="n">arg</span><span class="p">[</span><span class="n">iarg</span><span class="p">],</span><span class="w"> </span><span class="s">"overwrite"</span><span class="p">)</span><span class="w"> </span><span class="o">==</span><span class="w"> </span><span class="mi">0</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
|
|
<span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">iarg</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="mi">2</span><span class="w"> </span><span class="o">></span><span class="w"> </span><span class="n">narg</span><span class="p">)</span><span class="w"> </span><span class="n">utils</span><span class="o">::</span><span class="n">missing_cmd_args</span><span class="p">(</span><span class="n">FLERR</span><span class="p">,</span><span class="w"> </span><span class="s">"geturl overwrite"</span><span class="p">,</span><span class="w"> </span><span class="n">error</span><span class="p">);</span>
|
|
<span class="w"> </span><span class="n">overwrite</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">utils</span><span class="o">::</span><span class="n">logical</span><span class="p">(</span><span class="n">FLERR</span><span class="p">,</span><span class="w"> </span><span class="n">arg</span><span class="p">[</span><span class="n">iarg</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="mi">1</span><span class="p">],</span><span class="w"> </span><span class="nb">false</span><span class="p">,</span><span class="w"> </span><span class="n">lmp</span><span class="p">);</span>
|
|
<span class="w"> </span><span class="o">++</span><span class="n">iarg</span><span class="p">;</span>
|
|
<span class="w"> </span><span class="p">}</span><span class="w"> </span><span class="k">else</span><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">strcmp</span><span class="p">(</span><span class="n">arg</span><span class="p">[</span><span class="n">iarg</span><span class="p">],</span><span class="w"> </span><span class="s">"verify"</span><span class="p">)</span><span class="w"> </span><span class="o">==</span><span class="w"> </span><span class="mi">0</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
|
|
<span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">iarg</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="mi">2</span><span class="w"> </span><span class="o">></span><span class="w"> </span><span class="n">narg</span><span class="p">)</span><span class="w"> </span><span class="n">utils</span><span class="o">::</span><span class="n">missing_cmd_args</span><span class="p">(</span><span class="n">FLERR</span><span class="p">,</span><span class="w"> </span><span class="s">"geturl verify"</span><span class="p">,</span><span class="w"> </span><span class="n">error</span><span class="p">);</span>
|
|
<span class="w"> </span><span class="n">verify</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">utils</span><span class="o">::</span><span class="n">logical</span><span class="p">(</span><span class="n">FLERR</span><span class="p">,</span><span class="w"> </span><span class="n">arg</span><span class="p">[</span><span class="n">iarg</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="mi">1</span><span class="p">],</span><span class="w"> </span><span class="nb">false</span><span class="p">,</span><span class="w"> </span><span class="n">lmp</span><span class="p">);</span>
|
|
<span class="w"> </span><span class="o">++</span><span class="n">iarg</span><span class="p">;</span>
|
|
<span class="w"> </span><span class="p">}</span><span class="w"> </span><span class="k">else</span><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">strcmp</span><span class="p">(</span><span class="n">arg</span><span class="p">[</span><span class="n">iarg</span><span class="p">],</span><span class="w"> </span><span class="s">"verbose"</span><span class="p">)</span><span class="w"> </span><span class="o">==</span><span class="w"> </span><span class="mi">0</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
|
|
<span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">iarg</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="mi">2</span><span class="w"> </span><span class="o">></span><span class="w"> </span><span class="n">narg</span><span class="p">)</span><span class="w"> </span><span class="n">utils</span><span class="o">::</span><span class="n">missing_cmd_args</span><span class="p">(</span><span class="n">FLERR</span><span class="p">,</span><span class="w"> </span><span class="s">"geturl verbose"</span><span class="p">,</span><span class="w"> </span><span class="n">error</span><span class="p">);</span>
|
|
<span class="w"> </span><span class="n">verbose</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">utils</span><span class="o">::</span><span class="n">logical</span><span class="p">(</span><span class="n">FLERR</span><span class="p">,</span><span class="w"> </span><span class="n">arg</span><span class="p">[</span><span class="n">iarg</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="mi">1</span><span class="p">],</span><span class="w"> </span><span class="nb">false</span><span class="p">,</span><span class="w"> </span><span class="n">lmp</span><span class="p">);</span>
|
|
<span class="w"> </span><span class="o">++</span><span class="n">iarg</span><span class="p">;</span>
|
|
<span class="w"> </span><span class="p">}</span><span class="w"> </span><span class="k">else</span><span class="w"> </span><span class="p">{</span>
|
|
<span class="w"> </span><span class="n">error</span><span class="o">-></span><span class="n">all</span><span class="p">(</span><span class="n">FLERR</span><span class="p">,</span><span class="w"> </span><span class="s">"Unknown geturl keyword: {}"</span><span class="p">,</span><span class="w"> </span><span class="n">arg</span><span class="p">[</span><span class="n">iarg</span><span class="p">]);</span>
|
|
<span class="w"> </span><span class="p">}</span>
|
|
<span class="w"> </span><span class="o">++</span><span class="n">iarg</span><span class="p">;</span>
|
|
<span class="p">}</span>
|
|
</pre></div>
|
|
</div>
|
|
<p>This block parses the optional arguments following the URL and stops with an
|
|
error if there are arguments missing or an unknown argument is encountered.</p>
|
|
<div class="highlight-c++ notranslate"><div class="highlight"><pre><span></span><span class="c1">// only download files from rank 0</span>
|
|
|
|
<span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">comm</span><span class="o">-></span><span class="n">me</span><span class="w"> </span><span class="o">!=</span><span class="w"> </span><span class="mi">0</span><span class="p">)</span><span class="w"> </span><span class="k">return</span><span class="p">;</span>
|
|
|
|
<span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="o">!</span><span class="n">overwrite</span><span class="w"> </span><span class="o">&&</span><span class="w"> </span><span class="n">platform</span><span class="o">::</span><span class="n">file_is_readable</span><span class="p">(</span><span class="n">output</span><span class="p">))</span><span class="w"> </span><span class="k">return</span><span class="p">;</span>
|
|
|
|
<span class="c1">// open output file for writing</span>
|
|
|
|
<span class="kt">FILE</span><span class="w"> </span><span class="o">*</span><span class="n">out</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">fopen</span><span class="p">(</span><span class="n">output</span><span class="p">.</span><span class="n">c_str</span><span class="p">(),</span><span class="w"> </span><span class="s">"wb"</span><span class="p">);</span>
|
|
<span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="o">!</span><span class="n">out</span><span class="p">)</span>
|
|
<span class="w"> </span><span class="n">error</span><span class="o">-></span><span class="n">all</span><span class="p">(</span><span class="n">FLERR</span><span class="p">,</span><span class="w"> </span><span class="s">"Cannot open output file {} for writing: {}"</span><span class="p">,</span><span class="w"> </span><span class="n">output</span><span class="p">,</span><span class="w"> </span><span class="n">utils</span><span class="o">::</span><span class="n">getsyserror</span><span class="p">());</span>
|
|
</pre></div>
|
|
</div>
|
|
<p>Here all MPI ranks other than 0 will return, so that the URL download will
|
|
only happen from a single MPI rank. For that rank the output file is opened
|
|
for writing using the C library function <code class="docutils literal notranslate"><span class="pre">fopen()</span></code>.</p>
|
|
<div class="highlight-c++ notranslate"><div class="highlight"><pre><span></span><span class="c1">// initialize curl and perform download</span>
|
|
|
|
<span class="n">CURL</span><span class="w"> </span><span class="o">*</span><span class="n">curl</span><span class="p">;</span>
|
|
<span class="n">curl_global_init</span><span class="p">(</span><span class="n">CURL_GLOBAL_DEFAULT</span><span class="p">);</span>
|
|
<span class="n">curl</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">curl_easy_init</span><span class="p">();</span>
|
|
<span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">curl</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
|
|
<span class="w"> </span><span class="p">(</span><span class="kt">void</span><span class="p">)</span><span class="w"> </span><span class="n">curl_easy_setopt</span><span class="p">(</span><span class="n">curl</span><span class="p">,</span><span class="w"> </span><span class="n">CURLOPT_URL</span><span class="p">,</span><span class="w"> </span><span class="n">url</span><span class="p">.</span><span class="n">c_str</span><span class="p">());</span>
|
|
<span class="w"> </span><span class="p">(</span><span class="kt">void</span><span class="p">)</span><span class="w"> </span><span class="n">curl_easy_setopt</span><span class="p">(</span><span class="n">curl</span><span class="p">,</span><span class="w"> </span><span class="n">CURLOPT_WRITEDATA</span><span class="p">,</span><span class="w"> </span><span class="p">(</span><span class="kt">void</span><span class="w"> </span><span class="o">*</span><span class="p">)</span><span class="w"> </span><span class="n">out</span><span class="p">);</span>
|
|
<span class="w"> </span><span class="p">(</span><span class="kt">void</span><span class="p">)</span><span class="w"> </span><span class="n">curl_easy_setopt</span><span class="p">(</span><span class="n">curl</span><span class="p">,</span><span class="w"> </span><span class="n">CURLOPT_FILETIME</span><span class="p">,</span><span class="w"> </span><span class="mf">1L</span><span class="p">);</span>
|
|
<span class="w"> </span><span class="p">(</span><span class="kt">void</span><span class="p">)</span><span class="w"> </span><span class="n">curl_easy_setopt</span><span class="p">(</span><span class="n">curl</span><span class="p">,</span><span class="w"> </span><span class="n">CURLOPT_FAILONERROR</span><span class="p">,</span><span class="w"> </span><span class="mf">1L</span><span class="p">);</span>
|
|
<span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">verbose</span><span class="w"> </span><span class="o">&&</span><span class="w"> </span><span class="n">screen</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
|
|
<span class="w"> </span><span class="p">(</span><span class="kt">void</span><span class="p">)</span><span class="w"> </span><span class="n">curl_easy_setopt</span><span class="p">(</span><span class="n">curl</span><span class="p">,</span><span class="w"> </span><span class="n">CURLOPT_VERBOSE</span><span class="p">,</span><span class="w"> </span><span class="mf">1L</span><span class="p">);</span>
|
|
<span class="w"> </span><span class="p">(</span><span class="kt">void</span><span class="p">)</span><span class="w"> </span><span class="n">curl_easy_setopt</span><span class="p">(</span><span class="n">curl</span><span class="p">,</span><span class="w"> </span><span class="n">CURLOPT_STDERR</span><span class="p">,</span><span class="w"> </span><span class="p">(</span><span class="kt">void</span><span class="w"> </span><span class="o">*</span><span class="p">)</span><span class="w"> </span><span class="n">screen</span><span class="p">);</span>
|
|
<span class="w"> </span><span class="p">}</span>
|
|
<span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="o">!</span><span class="n">verify</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
|
|
<span class="w"> </span><span class="p">(</span><span class="kt">void</span><span class="p">)</span><span class="w"> </span><span class="n">curl_easy_setopt</span><span class="p">(</span><span class="n">curl</span><span class="p">,</span><span class="w"> </span><span class="n">CURLOPT_SSL_VERIFYPEER</span><span class="p">,</span><span class="w"> </span><span class="mf">0L</span><span class="p">);</span>
|
|
<span class="w"> </span><span class="p">(</span><span class="kt">void</span><span class="p">)</span><span class="w"> </span><span class="n">curl_easy_setopt</span><span class="p">(</span><span class="n">curl</span><span class="p">,</span><span class="w"> </span><span class="n">CURLOPT_SSL_VERIFYHOST</span><span class="p">,</span><span class="w"> </span><span class="mf">0L</span><span class="p">);</span>
|
|
<span class="w"> </span><span class="p">}</span>
|
|
<span class="w"> </span><span class="k">auto</span><span class="w"> </span><span class="n">res</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">curl_easy_perform</span><span class="p">(</span><span class="n">curl</span><span class="p">);</span>
|
|
<span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">res</span><span class="w"> </span><span class="o">!=</span><span class="w"> </span><span class="n">CURLE_OK</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
|
|
<span class="w"> </span><span class="kt">long</span><span class="w"> </span><span class="n">response</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="mf">0L</span><span class="p">;</span>
|
|
<span class="w"> </span><span class="n">curl_easy_getinfo</span><span class="p">(</span><span class="n">curl</span><span class="p">,</span><span class="w"> </span><span class="n">CURLINFO_RESPONSE_CODE</span><span class="p">,</span><span class="w"> </span><span class="o">&</span><span class="n">response</span><span class="p">);</span>
|
|
<span class="w"> </span><span class="n">error</span><span class="o">-></span><span class="n">one</span><span class="p">(</span><span class="n">FLERR</span><span class="p">,</span><span class="w"> </span><span class="s">"Download of {} failed with: {} {}"</span><span class="p">,</span><span class="w"> </span><span class="n">output</span><span class="p">,</span><span class="w"> </span><span class="n">curl_easy_strerror</span><span class="p">(</span><span class="n">res</span><span class="p">),</span>
|
|
<span class="w"> </span><span class="n">response</span><span class="p">);</span>
|
|
<span class="w"> </span><span class="p">}</span>
|
|
<span class="w"> </span><span class="n">curl_easy_cleanup</span><span class="p">(</span><span class="n">curl</span><span class="p">);</span>
|
|
</pre></div>
|
|
</div>
|
|
<p>This block now implements the actual URL download with the selected options
|
|
via the “easy” interface of <em>libcurl</em>. For the details of what these
|
|
function calls do, please have a look at the <a class="reference external" href="https://curl.se/libcurl/c/allfuncs.html">*libcurl documentation</a>.</p>
|
|
<blockquote>
|
|
<div><div class="highlight-c++ notranslate"><div class="highlight"><pre><span></span><span class="w"> </span><span class="p">}</span>
|
|
<span class="w"> </span><span class="n">curl_global_cleanup</span><span class="p">();</span>
|
|
<span class="w"> </span><span class="n">fclose</span><span class="p">(</span><span class="n">out</span><span class="p">);</span>
|
|
<span class="cp">#endif</span>
|
|
<span class="p">}</span>
|
|
</pre></div>
|
|
</div>
|
|
</div></blockquote>
|
|
<p>Finally, the previously opened file is closed and the command is complete.</p>
|
|
</section>
|
|
</section>
|
|
|
|
|
|
</div>
|
|
</div>
|
|
<footer><div class="rst-footer-buttons" role="navigation" aria-label="Footer">
|
|
<a href="Developer_write_fix.html" class="btn btn-neutral float-left" title="4.8.7. Writing a new fix style" accesskey="p" rel="prev"><span class="fa fa-arrow-circle-left" aria-hidden="true"></span> Previous</a>
|
|
<a href="Developer_notes.html" class="btn btn-neutral float-right" title="4.9. Notes for developers and code maintainers" accesskey="n" rel="next">Next <span class="fa fa-arrow-circle-right" aria-hidden="true"></span></a>
|
|
</div>
|
|
|
|
<hr/>
|
|
|
|
<div role="contentinfo">
|
|
<p>© Copyright 2003-2025 Sandia Corporation.</p>
|
|
</div>
|
|
|
|
Built with <a href="https://www.sphinx-doc.org/">Sphinx</a> using a
|
|
<a href="https://github.com/readthedocs/sphinx_rtd_theme">theme</a>
|
|
provided by <a href="https://readthedocs.org">Read the Docs</a>.
|
|
|
|
|
|
</footer>
|
|
</div>
|
|
</div>
|
|
</section>
|
|
</div>
|
|
<script>
|
|
jQuery(function () {
|
|
SphinxRtdTheme.Navigation.enable(false);
|
|
});
|
|
</script>
|
|
|
|
</body>
|
|
</html> |