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POCross-platform compatibility of dprintf
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2113539
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2010-01-21T22:45:41.373
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2017-03-06T19:25:24.760
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2017-03-06T19:25:24.760
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Linux has this nice function <a href="http://linux.die.net/man/3/dprintf" rel="nofollow noreferrer"><code>dprintf</code></a>: <blockquote> The functions <code>dprintf()</code> and <code>vdprintf()</code> (as found in the glibc2 library) are exact analogues of <code>fprintf()</code> and <code>vfprintf()</code>, except that they output to a file descriptor fd instead of to a given stream. </blockquote> however as that same source points out: <blockquote> These functions are GNU extensions, not in C or POSIX. Clearly, the names were badly chosen. Many systems (like MacOS) have incompatible functions called <code>dprintf()</code>, usually some debugging version of <code>printf()</code>, perhaps with a prototype like </blockquote> <pre><code>void dprintf (int level, const char *format, ...); </code></pre> <blockquote> where the first parameter is a debugging level (and output is to <code>stderr</code>). Moreover, <code>dprintf()</code> (or <code>DPRINTF</code>) is also a popular macro name for a debugging <code>printf</code>. So, probably, it is better to avoid this function in programs intended to be portable. </blockquote> <h2>My question</h2> How can I make a setup that will safely call the <code>dprintf</code> that I want, if it exists, or fail to compile with some reasonably sane error message if that function doesn't exist? I guess I'd do something like this: <pre><code>#ifdef SOMETHING #define Dprintf dprintf #else #error "no dprintf" #endif </code></pre> but I don't know what <code>SOMETHING</code> should be. I guess I could restrict it to just Linux but could I make it looser?
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<c><linux><posix><conditional-compilation>
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Cross-platform compatibility of dprintf
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