16 lines
11 KiB
HTML
16 lines
11 KiB
HTML
<!DOCTYPE html>
|
|
<html lang="en"><head><meta charset="UTF-8"/><meta name="viewport" content="width=device-width, initial-scale=1.0"/><title>Handling Operating System Variation · The Julia Language</title><script>(function(i,s,o,g,r,a,m){i['GoogleAnalyticsObject']=r;i[r]=i[r]||function(){
|
|
(i[r].q=i[r].q||[]).push(arguments)},i[r].l=1*new Date();a=s.createElement(o),
|
|
m=s.getElementsByTagName(o)[0];a.async=1;a.src=g;m.parentNode.insertBefore(a,m)
|
|
})(window,document,'script','https://www.google-analytics.com/analytics.js','ga');
|
|
|
|
ga('create', 'UA-28835595-6', 'auto');
|
|
ga('send', 'pageview');
|
|
</script><link href="https://cdnjs.cloudflare.com/ajax/libs/normalize/4.2.0/normalize.min.css" rel="stylesheet" type="text/css"/><link href="https://fonts.googleapis.com/css?family=Lato|Roboto+Mono" rel="stylesheet" type="text/css"/><link href="https://cdnjs.cloudflare.com/ajax/libs/font-awesome/4.6.3/css/font-awesome.min.css" rel="stylesheet" type="text/css"/><script>documenterBaseURL=".."</script><script src="https://cdnjs.cloudflare.com/ajax/libs/require.js/2.2.0/require.min.js" data-main="../assets/documenter.js"></script><script src="../siteinfo.js"></script><script src="../../versions.js"></script><link href="../assets/highlightjs/default.css" rel="stylesheet" type="text/css"/><link href="../assets/documenter.css" rel="stylesheet" type="text/css"/></head><body><nav class="toc"><a href="../index.html"><img class="logo" src="../assets/logo.png" alt="The Julia Language logo"/></a><h1>The Julia Language</h1><select id="version-selector" onChange="window.location.href=this.value" style="visibility: hidden"></select><form class="search" action="../search.html"><input id="search-query" name="q" type="text" placeholder="Search docs"/></form><ul><li><a class="toctext" href="../index.html">Home</a></li><li><span class="toctext">Manual</span><ul><li><a class="toctext" href="introduction.html">Introduction</a></li><li><a class="toctext" href="getting-started.html">Getting Started</a></li><li><a class="toctext" href="variables.html">Variables</a></li><li><a class="toctext" href="integers-and-floating-point-numbers.html">Integers and Floating-Point Numbers</a></li><li><a class="toctext" href="mathematical-operations.html">Mathematical Operations and Elementary Functions</a></li><li><a class="toctext" href="complex-and-rational-numbers.html">Complex and Rational Numbers</a></li><li><a class="toctext" href="strings.html">Strings</a></li><li><a class="toctext" href="functions.html">Functions</a></li><li><a class="toctext" href="control-flow.html">Control Flow</a></li><li><a class="toctext" href="variables-and-scoping.html">Scope of Variables</a></li><li><a class="toctext" href="types.html">Types</a></li><li><a class="toctext" href="methods.html">Methods</a></li><li><a class="toctext" href="constructors.html">Constructors</a></li><li><a class="toctext" href="conversion-and-promotion.html">Conversion and Promotion</a></li><li><a class="toctext" href="interfaces.html">Interfaces</a></li><li><a class="toctext" href="modules.html">Modules</a></li><li><a class="toctext" href="documentation.html">Documentation</a></li><li><a class="toctext" href="metaprogramming.html">Metaprogramming</a></li><li><a class="toctext" href="arrays.html">Multi-dimensional Arrays</a></li><li><a class="toctext" href="linear-algebra.html">Linear algebra</a></li><li><a class="toctext" href="networking-and-streams.html">Networking and Streams</a></li><li><a class="toctext" href="parallel-computing.html">Parallel Computing</a></li><li><a class="toctext" href="dates.html">Date and DateTime</a></li><li><a class="toctext" href="interacting-with-julia.html">Interacting With Julia</a></li><li><a class="toctext" href="running-external-programs.html">Running External Programs</a></li><li><a class="toctext" href="calling-c-and-fortran-code.html">Calling C and Fortran Code</a></li><li class="current"><a class="toctext" href="handling-operating-system-variation.html">Handling Operating System Variation</a><ul class="internal"></ul></li><li><a class="toctext" href="environment-variables.html">Environment Variables</a></li><li><a class="toctext" href="embedding.html">Embedding Julia</a></li><li><a class="toctext" href="packages.html">Packages</a></li><li><a class="toctext" href="profile.html">Profiling</a></li><li><a class="toctext" href="stacktraces.html">Stack Traces</a></li><li><a class="toctext" href="performance-tips.html">Performance Tips</a></li><li><a class="toctext" href="workflow-tips.html">Workflow Tips</a></li><li><a class="toctext" href="style-guide.html">Style Guide</a></li><li><a class="toctext" href="faq.html">Frequently Asked Questions</a></li><li><a class="toctext" href="noteworthy-differences.html">Noteworthy Differences from other Languages</a></li><li><a class="toctext" href="unicode-input.html">Unicode Input</a></li></ul></li><li><span class="toctext">Standard Library</span><ul><li><a class="toctext" href="../stdlib/base.html">Essentials</a></li><li><a class="toctext" href="../stdlib/collections.html">Collections and Data Structures</a></li><li><a class="toctext" href="../stdlib/math.html">Mathematics</a></li><li><a class="toctext" href="../stdlib/numbers.html">Numbers</a></li><li><a class="toctext" href="../stdlib/strings.html">Strings</a></li><li><a class="toctext" href="../stdlib/arrays.html">Arrays</a></li><li><a class="toctext" href="../stdlib/parallel.html">Tasks and Parallel Computing</a></li><li><a class="toctext" href="../stdlib/linalg.html">Linear Algebra</a></li><li><a class="toctext" href="../stdlib/constants.html">Constants</a></li><li><a class="toctext" href="../stdlib/file.html">Filesystem</a></li><li><a class="toctext" href="../stdlib/io-network.html">I/O and Network</a></li><li><a class="toctext" href="../stdlib/punctuation.html">Punctuation</a></li><li><a class="toctext" href="../stdlib/sort.html">Sorting and Related Functions</a></li><li><a class="toctext" href="../stdlib/pkg.html">Package Manager Functions</a></li><li><a class="toctext" href="../stdlib/dates.html">Dates and Time</a></li><li><a class="toctext" href="../stdlib/iterators.html">Iteration utilities</a></li><li><a class="toctext" href="../stdlib/test.html">Unit Testing</a></li><li><a class="toctext" href="../stdlib/c.html">C Interface</a></li><li><a class="toctext" href="../stdlib/libc.html">C Standard Library</a></li><li><a class="toctext" href="../stdlib/libdl.html">Dynamic Linker</a></li><li><a class="toctext" href="../stdlib/profile.html">Profiling</a></li><li><a class="toctext" href="../stdlib/stacktraces.html">StackTraces</a></li><li><a class="toctext" href="../stdlib/simd-types.html">SIMD Support</a></li></ul></li><li><span class="toctext">Developer Documentation</span><ul><li><a class="toctext" href="../devdocs/reflection.html">Reflection and introspection</a></li><li><span class="toctext">Documentation of Julia's Internals</span><ul><li><a class="toctext" href="../devdocs/init.html">Initialization of the Julia runtime</a></li><li><a class="toctext" href="../devdocs/ast.html">Julia ASTs</a></li><li><a class="toctext" href="../devdocs/types.html">More about types</a></li><li><a class="toctext" href="../devdocs/object.html">Memory layout of Julia Objects</a></li><li><a class="toctext" href="../devdocs/eval.html">Eval of Julia code</a></li><li><a class="toctext" href="../devdocs/callconv.html">Calling Conventions</a></li><li><a class="toctext" href="../devdocs/compiler.html">High-level Overview of the Native-Code Generation Process</a></li><li><a class="toctext" href="../devdocs/functions.html">Julia Functions</a></li><li><a class="toctext" href="../devdocs/cartesian.html">Base.Cartesian</a></li><li><a class="toctext" href="../devdocs/meta.html">Talking to the compiler (the <code>:meta</code> mechanism)</a></li><li><a class="toctext" href="../devdocs/subarrays.html">SubArrays</a></li><li><a class="toctext" href="../devdocs/sysimg.html">System Image Building</a></li><li><a class="toctext" href="../devdocs/llvm.html">Working with LLVM</a></li><li><a class="toctext" href="../devdocs/stdio.html">printf() and stdio in the Julia runtime</a></li><li><a class="toctext" href="../devdocs/boundscheck.html">Bounds checking</a></li><li><a class="toctext" href="../devdocs/locks.html">Proper maintenance and care of multi-threading locks</a></li><li><a class="toctext" href="../devdocs/offset-arrays.html">Arrays with custom indices</a></li><li><a class="toctext" href="../devdocs/libgit2.html">Base.LibGit2</a></li><li><a class="toctext" href="../devdocs/require.html">Module loading</a></li></ul></li><li><span class="toctext">Developing/debugging Julia's C code</span><ul><li><a class="toctext" href="../devdocs/backtraces.html">Reporting and analyzing crashes (segfaults)</a></li><li><a class="toctext" href="../devdocs/debuggingtips.html">gdb debugging tips</a></li><li><a class="toctext" href="../devdocs/valgrind.html">Using Valgrind with Julia</a></li><li><a class="toctext" href="../devdocs/sanitizers.html">Sanitizer support</a></li></ul></li></ul></li></ul></nav><article id="docs"><header><nav><ul><li>Manual</li><li><a href="handling-operating-system-variation.html">Handling Operating System Variation</a></li></ul><a class="edit-page" href="https://github.com/JuliaLang/julia/tree/d386e40c17d43b79fc89d3e579fc04547241787c/doc/src/manual/handling-operating-system-variation.md"><span class="fa"></span> Edit on GitHub</a></nav><hr/><div id="topbar"><span>Handling Operating System Variation</span><a class="fa fa-bars" href="#"></a></div></header><h1><a class="nav-anchor" id="Handling-Operating-System-Variation-1" href="#Handling-Operating-System-Variation-1">Handling Operating System Variation</a></h1><p>When dealing with platform libraries, it is often necessary to provide special cases for various platforms. The variable <code>Sys.KERNEL</code> can be used to write these special cases. There are several functions intended to make this easier: <code>is_unix</code>, <code>is_linux</code>, <code>is_apple</code>, <code>is_bsd</code>, and <code>is_windows</code>. These may be used as follows:</p><pre><code class="language-julia">if is_windows()
|
|
some_complicated_thing(a)
|
|
end</code></pre><p>Note that <code>is_linux</code> and <code>is_apple</code> are mutually exclusive subsets of <code>is_unix</code>. Additionally, there is a macro <code>@static</code> which makes it possible to use these functions to conditionally hide invalid code, as demonstrated in the following examples.</p><p>Simple blocks:</p><pre><code class="language-none">ccall( (@static is_windows() ? :_fopen : :fopen), ...)</code></pre><p>Complex blocks:</p><pre><code class="language-julia">@static if is_linux()
|
|
some_complicated_thing(a)
|
|
else
|
|
some_different_thing(a)
|
|
end</code></pre><p>When chaining conditionals (including if/elseif/end), the <code>@static</code> must be repeated for each level (parentheses optional, but recommended for readability):</p><pre><code class="language-julia">@static is_windows() ? :a : (@static is_apple() ? :b : :c)</code></pre><footer><hr/><a class="previous" href="calling-c-and-fortran-code.html"><span class="direction">Previous</span><span class="title">Calling C and Fortran Code</span></a><a class="next" href="environment-variables.html"><span class="direction">Next</span><span class="title">Environment Variables</span></a></footer></article></body></html>
|