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diff --git a/doc/libstddjb/genwrite.html b/doc/libstddjb/genwrite.html new file mode 100644 index 0000000..33ff4d3 --- /dev/null +++ b/doc/libstddjb/genwrite.html @@ -0,0 +1,98 @@ +<html> + <head> + <meta http-equiv="Content-Type" content="text/html; charset=UTF-8" /> + <meta http-equiv="Content-Language" content="en" /> + <title>skalibs: the genwrite library interface</title> + <meta name="Description" content="skalibs: the genwrite library interface" /> + <meta name="Keywords" content="skalibs c unix genwrite buffer stralloc write library libstddjb" /> + <!-- <link rel="stylesheet" type="text/css" href="http://skarnet.org/default.css" /> --> + </head> +<body> + +<p> +<a href="index.html">libstddjb</a><br /> +<a href="../libskarnet.html">libskarnet</a><br /> +<a href="../index.html">skalibs</a><br /> +<a href="http://skarnet.org/software/">Software</a><br /> +<a href="http://skarnet.org/">skarnet.org</a> +</p> + +<h1> The <tt>genwrite</tt> library interface </h1> + +<p> + The following functions are declared in the <tt>skalibs/genwrite.h</tt> header, +and implemented in the <tt>libskarnet.a</tt> or <tt>libskarnet.so</tt> library. +</p> + +<h2> General information </h2> + +<p> + <tt>genwrite</tt> is syntactic sugar to help write functions that might +want to write either to memory or to a file descriptor. +</p> + +<p> + Writing to memory is achieved via appending to a +<a href="stralloc.html">stralloc</a>; writing to a file descriptor is achieved +via appending to a <a href="buffer.html">buffer</a> or a +<a href="bufalloc.html">bufalloc</a>. +</p> + +<h2> Usage </h2> + +<p> + A <tt>genwrite_t</tt> structure contains a pointer to a function that writes +stuff to the target without flushing it +(which can be <tt>genwrite_put_stralloc</tt>, <tt>genwrite_put_buffer</tt>, +<tt>genwrite_put_bufalloc</tt> or any +compatible user-defined function) in <tt>.put</tt>, a pointer to a function +that flushes the target (which can be <tt>genwrite_flush_stralloc</tt>, +<tt>genwrite_flush_buffer</tt>, <tt>genwrite_flush_bufalloc</tt> or any +compatible user-defined function) in <tt>.flush</tt>, and a pointer to +the target writing structure in <tt>.target</tt>. +</p> + +<p> + Users should define a <tt>genwrite_t</tt> first, using the provided functions, +and give applications a pointer <tt>gp</tt> to this structure. To write <em>len</em> +characters at position <em>s</em> to the target, the application should then call +<code>(*gp->put)(gp->target, s, len)</code>. When it is done writing, the +application should call <code>(*gp->flush)(gp->target)</code> to flush the +output. +</p> + +<p> + <tt>genwrite_stdout</tt> and <tt>genwrite_stderr</tt> are predefined; they +write to <tt>buffer_1</tt> and <tt>buffer_2</tt> respectively. +</p> + +<h2> Macros </h2> + +<p> +<code> GENWRITE_STRALLOC_INIT(sa) </code> <br /> +Declares a <tt>genwrite_t</tt> writing to the stralloc *<em>sa</em>. +</p> + +<p> +<code> GENWRITE_BUFFER_INIT(b) </code> <br /> +Declares a <tt>genwrite_t</tt> writing to the buffer *<em>b</em>. Use +of such a buffer might interact badly with nonblocking I/O. +</p> + +<p> +<code> GENWRITE_BUFALLOC_INIT(ba) </code> <br /> +Declares a <tt>genwrite_t</tt> writing to the bufalloc *<em>ba</em>. +</p> + +<h2> Note </h2> + +<p> +Object-oriented programming in C is inefficient and cumbersome. It is +usually possible to avoid it in Unix system programming, because Unix +primitives are often generic enough. Unfortunately, it is not the case +here: Unix does not provide an abstraction representing either a file +or a memory buffer. So an object-oriented approach is unavoidable. +</p> + +</body> +</html> |