technical/api-argv-array.html

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<body class="article">
<div id="header">
<h1>argv-array API</h1>
</div>
<div id="content">
<div id="preamble">
<div class="sectionbody">
<div class="paragraph"><p>The argv-array API allows one to dynamically build and store
NULL-terminated lists.  An argv-array maintains the invariant that the
<code>argv</code> member always points to a non-NULL array, and that the array is
always NULL-terminated at the element pointed to by <code>argv[argc]</code>. This
makes the result suitable for passing to functions expecting to receive
argv from main(), or the <a href="api-run-command.html">run-command API</a>.</p></div>
<div class="paragraph"><p>The <a href="api-string-list.html">string-list API</a> is similar, but cannot be
used for these purposes; instead of storing a straight string pointer,
it contains an item structure with a <code>util</code> field that is not compatible
with the traditional argv interface.</p></div>
<div class="paragraph"><p>Each <code>argv_array</code> manages its own memory. Any strings pushed into the
array are duplicated, and all memory is freed by argv_array_clear().</p></div>
</div>
</div>
<div class="sect1">
<h2 id="_data_structures">Data Structures</h2>
<div class="sectionbody">
<div class="dlist"><dl>
<dt class="hdlist1">
<code>struct argv_array</code>
</dt>
<dd>
<p>
        A single array. This should be initialized by assignment from
        <code>ARGV_ARRAY_INIT</code>, or by calling <code>argv_array_init</code>. The <code>argv</code>
        member contains the actual array; the <code>argc</code> member contains the
        number of elements in the array, not including the terminating
        NULL.
</p>
</dd>
</dl></div>
</div>
</div>
<div class="sect1">
<h2 id="_functions">Functions</h2>
<div class="sectionbody">
<div class="dlist"><dl>
<dt class="hdlist1">
<code>argv_array_init</code>
</dt>
<dd>
<p>
        Initialize an array. This is no different than assigning from
        <code>ARGV_ARRAY_INIT</code>.
</p>
</dd>
<dt class="hdlist1">
<code>argv_array_push</code>
</dt>
<dd>
<p>
        Push a copy of a string onto the end of the array.
</p>
</dd>
<dt class="hdlist1">
<code>argv_array_pushl</code>
</dt>
<dd>
<p>
        Push a list of strings onto the end of the array. The arguments
        should be a list of <code>const char *</code> strings, terminated by a NULL
        argument.
</p>
</dd>
<dt class="hdlist1">
<code>argv_array_pushf</code>
</dt>
<dd>
<p>
        Format a string and push it onto the end of the array. This is a
        convenience wrapper combining <code>strbuf_addf</code> and <code>argv_array_push</code>.
</p>
</dd>
<dt class="hdlist1">
<code>argv_array_pop</code>
</dt>
<dd>
<p>
        Remove the final element from the array. If there are no
        elements in the array, do nothing.
</p>
</dd>
<dt class="hdlist1">
<code>argv_array_clear</code>
</dt>
<dd>
<p>
        Free all memory associated with the array and return it to the
        initial, empty state.
</p>
</dd>
<dt class="hdlist1">
<code>argv_array_detach</code>
</dt>
<dd>
<p>
        Detach the argv array from the <code>struct argv_array</code>, transferring
        ownership of the allocated array and strings.
</p>
</dd>
<dt class="hdlist1">
<code>argv_array_free_detached</code>
</dt>
<dd>
<p>
        Free the memory allocated by a <code>struct argv_array</code> that was later
        detached and is now no longer needed.
</p>
</dd>
</dl></div>
</div>
</div>
</div>
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Last updated 2013-04-12 14:32:32 PDT
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