Server : Apache
System : Linux server1.cgrithy.com 3.10.0-1160.95.1.el7.x86_64 #1 SMP Mon Jul 24 13:59:37 UTC 2023 x86_64
User : nobody ( 99)
PHP Version : 8.1.23
Disable Function : NONE
Directory : /usr/share/doc/git-1.8.3.1/technical/
|
Server : Apache System : Linux server1.cgrithy.com 3.10.0-1160.95.1.el7.x86_64 #1 SMP Mon Jul 24 13:59:37 UTC 2023 x86_64 User : nobody ( 99) PHP Version : 8.1.23 Disable Function : NONE Directory : /usr/share/doc/git-1.8.3.1/technical/ |
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.1//EN"
"http://www.w3.org/TR/xhtml11/DTD/xhtml11.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en">
<head>
<meta http-equiv="Content-Type" content="application/xhtml+xml; charset=UTF-8" />
<meta name="generator" content="AsciiDoc 8.6.8" />
<title>parse-options API</title>
<style type="text/css">
/* Shared CSS for AsciiDoc xhtml11 and html5 backends */
/* Default font. */
body {
font-family: Georgia,serif;
}
/* Title font. */
h1, h2, h3, h4, h5, h6,
div.title, caption.title,
thead, p.table.header,
#toctitle,
#author, #revnumber, #revdate, #revremark,
#footer {
font-family: Arial,Helvetica,sans-serif;
}
body {
margin: 1em 5% 1em 5%;
}
a {
color: blue;
text-decoration: underline;
}
a:visited {
color: fuchsia;
}
em {
font-style: italic;
color: navy;
}
strong {
font-weight: bold;
color: #083194;
}
h1, h2, h3, h4, h5, h6 {
color: #527bbd;
margin-top: 1.2em;
margin-bottom: 0.5em;
line-height: 1.3;
}
h1, h2, h3 {
border-bottom: 2px solid silver;
}
h2 {
padding-top: 0.5em;
}
h3 {
float: left;
}
h3 + * {
clear: left;
}
h5 {
font-size: 1.0em;
}
div.sectionbody {
margin-left: 0;
}
hr {
border: 1px solid silver;
}
p {
margin-top: 0.5em;
margin-bottom: 0.5em;
}
ul, ol, li > p {
margin-top: 0;
}
ul > li { color: #aaa; }
ul > li > * { color: black; }
.monospaced, code, pre {
font-family: "Courier New", Courier, monospace;
font-size: inherit;
color: navy;
padding: 0;
margin: 0;
}
#author {
color: #527bbd;
font-weight: bold;
font-size: 1.1em;
}
#email {
}
#revnumber, #revdate, #revremark {
}
#footer {
font-size: small;
border-top: 2px solid silver;
padding-top: 0.5em;
margin-top: 4.0em;
}
#footer-text {
float: left;
padding-bottom: 0.5em;
}
#footer-badges {
float: right;
padding-bottom: 0.5em;
}
#preamble {
margin-top: 1.5em;
margin-bottom: 1.5em;
}
div.imageblock, div.exampleblock, div.verseblock,
div.quoteblock, div.literalblock, div.listingblock, div.sidebarblock,
div.admonitionblock {
margin-top: 1.0em;
margin-bottom: 1.5em;
}
div.admonitionblock {
margin-top: 2.0em;
margin-bottom: 2.0em;
margin-right: 10%;
color: #606060;
}
div.content { /* Block element content. */
padding: 0;
}
/* Block element titles. */
div.title, caption.title {
color: #527bbd;
font-weight: bold;
text-align: left;
margin-top: 1.0em;
margin-bottom: 0.5em;
}
div.title + * {
margin-top: 0;
}
td div.title:first-child {
margin-top: 0.0em;
}
div.content div.title:first-child {
margin-top: 0.0em;
}
div.content + div.title {
margin-top: 0.0em;
}
div.sidebarblock > div.content {
background: #ffffee;
border: 1px solid #dddddd;
border-left: 4px solid #f0f0f0;
padding: 0.5em;
}
div.listingblock > div.content {
border: 1px solid #dddddd;
border-left: 5px solid #f0f0f0;
background: #f8f8f8;
padding: 0.5em;
}
div.quoteblock, div.verseblock {
padding-left: 1.0em;
margin-left: 1.0em;
margin-right: 10%;
border-left: 5px solid #f0f0f0;
color: #888;
}
div.quoteblock > div.attribution {
padding-top: 0.5em;
text-align: right;
}
div.verseblock > pre.content {
font-family: inherit;
font-size: inherit;
}
div.verseblock > div.attribution {
padding-top: 0.75em;
text-align: left;
}
/* DEPRECATED: Pre version 8.2.7 verse style literal block. */
div.verseblock + div.attribution {
text-align: left;
}
div.admonitionblock .icon {
vertical-align: top;
font-size: 1.1em;
font-weight: bold;
text-decoration: underline;
color: #527bbd;
padding-right: 0.5em;
}
div.admonitionblock td.content {
padding-left: 0.5em;
border-left: 3px solid #dddddd;
}
div.exampleblock > div.content {
border-left: 3px solid #dddddd;
padding-left: 0.5em;
}
div.imageblock div.content { padding-left: 0; }
span.image img { border-style: none; }
a.image:visited { color: white; }
dl {
margin-top: 0.8em;
margin-bottom: 0.8em;
}
dt {
margin-top: 0.5em;
margin-bottom: 0;
font-style: normal;
color: navy;
}
dd > *:first-child {
margin-top: 0.1em;
}
ul, ol {
list-style-position: outside;
}
ol.arabic {
list-style-type: decimal;
}
ol.loweralpha {
list-style-type: lower-alpha;
}
ol.upperalpha {
list-style-type: upper-alpha;
}
ol.lowerroman {
list-style-type: lower-roman;
}
ol.upperroman {
list-style-type: upper-roman;
}
div.compact ul, div.compact ol,
div.compact p, div.compact p,
div.compact div, div.compact div {
margin-top: 0.1em;
margin-bottom: 0.1em;
}
tfoot {
font-weight: bold;
}
td > div.verse {
white-space: pre;
}
div.hdlist {
margin-top: 0.8em;
margin-bottom: 0.8em;
}
div.hdlist tr {
padding-bottom: 15px;
}
dt.hdlist1.strong, td.hdlist1.strong {
font-weight: bold;
}
td.hdlist1 {
vertical-align: top;
font-style: normal;
padding-right: 0.8em;
color: navy;
}
td.hdlist2 {
vertical-align: top;
}
div.hdlist.compact tr {
margin: 0;
padding-bottom: 0;
}
.comment {
background: yellow;
}
.footnote, .footnoteref {
font-size: 0.8em;
}
span.footnote, span.footnoteref {
vertical-align: super;
}
#footnotes {
margin: 20px 0 20px 0;
padding: 7px 0 0 0;
}
#footnotes div.footnote {
margin: 0 0 5px 0;
}
#footnotes hr {
border: none;
border-top: 1px solid silver;
height: 1px;
text-align: left;
margin-left: 0;
width: 20%;
min-width: 100px;
}
div.colist td {
padding-right: 0.5em;
padding-bottom: 0.3em;
vertical-align: top;
}
div.colist td img {
margin-top: 0.3em;
}
@media print {
#footer-badges { display: none; }
}
#toc {
margin-bottom: 2.5em;
}
#toctitle {
color: #527bbd;
font-size: 1.1em;
font-weight: bold;
margin-top: 1.0em;
margin-bottom: 0.1em;
}
div.toclevel0, div.toclevel1, div.toclevel2, div.toclevel3, div.toclevel4 {
margin-top: 0;
margin-bottom: 0;
}
div.toclevel2 {
margin-left: 2em;
font-size: 0.9em;
}
div.toclevel3 {
margin-left: 4em;
font-size: 0.9em;
}
div.toclevel4 {
margin-left: 6em;
font-size: 0.9em;
}
span.aqua { color: aqua; }
span.black { color: black; }
span.blue { color: blue; }
span.fuchsia { color: fuchsia; }
span.gray { color: gray; }
span.green { color: green; }
span.lime { color: lime; }
span.maroon { color: maroon; }
span.navy { color: navy; }
span.olive { color: olive; }
span.purple { color: purple; }
span.red { color: red; }
span.silver { color: silver; }
span.teal { color: teal; }
span.white { color: white; }
span.yellow { color: yellow; }
span.aqua-background { background: aqua; }
span.black-background { background: black; }
span.blue-background { background: blue; }
span.fuchsia-background { background: fuchsia; }
span.gray-background { background: gray; }
span.green-background { background: green; }
span.lime-background { background: lime; }
span.maroon-background { background: maroon; }
span.navy-background { background: navy; }
span.olive-background { background: olive; }
span.purple-background { background: purple; }
span.red-background { background: red; }
span.silver-background { background: silver; }
span.teal-background { background: teal; }
span.white-background { background: white; }
span.yellow-background { background: yellow; }
span.big { font-size: 2em; }
span.small { font-size: 0.6em; }
span.underline { text-decoration: underline; }
span.overline { text-decoration: overline; }
span.line-through { text-decoration: line-through; }
div.unbreakable { page-break-inside: avoid; }
/*
* xhtml11 specific
*
* */
div.tableblock {
margin-top: 1.0em;
margin-bottom: 1.5em;
}
div.tableblock > table {
border: 3px solid #527bbd;
}
thead, p.table.header {
font-weight: bold;
color: #527bbd;
}
p.table {
margin-top: 0;
}
/* Because the table frame attribute is overriden by CSS in most browsers. */
div.tableblock > table[frame="void"] {
border-style: none;
}
div.tableblock > table[frame="hsides"] {
border-left-style: none;
border-right-style: none;
}
div.tableblock > table[frame="vsides"] {
border-top-style: none;
border-bottom-style: none;
}
/*
* html5 specific
*
* */
table.tableblock {
margin-top: 1.0em;
margin-bottom: 1.5em;
}
thead, p.tableblock.header {
font-weight: bold;
color: #527bbd;
}
p.tableblock {
margin-top: 0;
}
table.tableblock {
border-width: 3px;
border-spacing: 0px;
border-style: solid;
border-color: #527bbd;
border-collapse: collapse;
}
th.tableblock, td.tableblock {
border-width: 1px;
padding: 4px;
border-style: solid;
border-color: #527bbd;
}
table.tableblock.frame-topbot {
border-left-style: hidden;
border-right-style: hidden;
}
table.tableblock.frame-sides {
border-top-style: hidden;
border-bottom-style: hidden;
}
table.tableblock.frame-none {
border-style: hidden;
}
th.tableblock.halign-left, td.tableblock.halign-left {
text-align: left;
}
th.tableblock.halign-center, td.tableblock.halign-center {
text-align: center;
}
th.tableblock.halign-right, td.tableblock.halign-right {
text-align: right;
}
th.tableblock.valign-top, td.tableblock.valign-top {
vertical-align: top;
}
th.tableblock.valign-middle, td.tableblock.valign-middle {
vertical-align: middle;
}
th.tableblock.valign-bottom, td.tableblock.valign-bottom {
vertical-align: bottom;
}
/*
* manpage specific
*
* */
body.manpage h1 {
padding-top: 0.5em;
padding-bottom: 0.5em;
border-top: 2px solid silver;
border-bottom: 2px solid silver;
}
body.manpage h2 {
border-style: none;
}
body.manpage div.sectionbody {
margin-left: 3em;
}
@media print {
body.manpage div#toc { display: none; }
}
</style>
<script type="text/javascript">
/*<+'])');
// Function that scans the DOM tree for header elements (the DOM2
// nodeIterator API would be a better technique but not supported by all
// browsers).
var iterate = function (el) {
for (var i = el.firstChild; i != null; i = i.nextSibling) {
if (i.nodeType == 1 /* Node.ELEMENT_NODE */) {
var mo = re.exec(i.tagName);
if (mo && (i.getAttribute("class") || i.getAttribute("className")) != "float") {
result[result.length] = new TocEntry(i, getText(i), mo[1]-1);
}
iterate(i);
}
}
}
iterate(el);
return result;
}
var toc = document.getElementById("toc");
if (!toc) {
return;
}
// Delete existing TOC entries in case we're reloading the TOC.
var tocEntriesToRemove = [];
var i;
for (i = 0; i < toc.childNodes.length; i++) {
var entry = toc.childNodes[i];
if (entry.nodeName.toLowerCase() == 'div'
&& entry.getAttribute("class")
&& entry.getAttribute("class").match(/^toclevel/))
tocEntriesToRemove.push(entry);
}
for (i = 0; i < tocEntriesToRemove.length; i++) {
toc.removeChild(tocEntriesToRemove[i]);
}
// Rebuild TOC entries.
var entries = tocEntries(document.getElementById("content"), toclevels);
for (var i = 0; i < entries.length; ++i) {
var entry = entries[i];
if (entry.element.id == "")
entry.element.id = "_toc_" + i;
var a = document.createElement("a");
a.href = "#" + entry.element.id;
a.appendChild(document.createTextNode(entry.text));
var div = document.createElement("div");
div.appendChild(a);
div.className = "toclevel" + entry.toclevel;
toc.appendChild(div);
}
if (entries.length == 0)
toc.parentNode.removeChild(toc);
},
/////////////////////////////////////////////////////////////////////
// Footnotes generator
/////////////////////////////////////////////////////////////////////
/* Based on footnote generation code from:
* http://www.brandspankingnew.net/archive/2005/07/format_footnote.html
*/
footnotes: function () {
// Delete existing footnote entries in case we're reloading the footnodes.
var i;
var noteholder = document.getElementById("footnotes");
if (!noteholder) {
return;
}
var entriesToRemove = [];
for (i = 0; i < noteholder.childNodes.length; i++) {
var entry = noteholder.childNodes[i];
if (entry.nodeName.toLowerCase() == 'div' && entry.getAttribute("class") == "footnote")
entriesToRemove.push(entry);
}
for (i = 0; i < entriesToRemove.length; i++) {
noteholder.removeChild(entriesToRemove[i]);
}
// Rebuild footnote entries.
var cont = document.getElementById("content");
var spans = cont.getElementsByTagName("span");
var refs = {};
var n = 0;
for (i=0; i<spans.length; i++) {
if (spans[i].className == "footnote") {
n++;
var note = spans[i].getAttribute("data-note");
if (!note) {
// Use [\s\S] in place of . so multi-line matches work.
// Because JavaScript has no s (dotall) regex flag.
note = spans[i].innerHTML.match(/\s*\[([\s\S]*)]\s*/)[1];
spans[i].innerHTML =
"[<a id='_footnoteref_" + n + "' href='#_footnote_" + n +
"' title='View footnote' class='footnote'>" + n + "</a>]";
spans[i].setAttribute("data-note", note);
}
noteholder.innerHTML +=
"<div class='footnote' id='_footnote_" + n + "'>" +
"<a href='#_footnoteref_" + n + "' title='Return to text'>" +
n + "</a>. " + note + "</div>";
var id =spans[i].getAttribute("id");
if (id != null) refs["#"+id] = n;
}
}
if (n == 0)
noteholder.parentNode.removeChild(noteholder);
else {
// Process footnoterefs.
for (i=0; i<spans.length; i++) {
if (spans[i].className == "footnoteref") {
var href = spans[i].getElementsByTagName("a")[0].getAttribute("href");
href = href.match(/#.*/)[0]; // Because IE return full URL.
n = refs[href];
spans[i].innerHTML =
"[<a href='#_footnote_" + n +
"' title='View footnote' class='footnote'>" + n + "</a>]";
}
}
}
},
install: function(toclevels) {
var timerId;
function reinstall() {
asciidoc.footnotes();
if (toclevels) {
asciidoc.toc(toclevels);
}
}
function reinstallAndRemoveTimer() {
clearInterval(timerId);
reinstall();
}
timerId = setInterval(reinstall, 500);
if (document.addEventListener)
document.addEventListener("DOMContentLoaded", reinstallAndRemoveTimer, false);
else
window.onload = reinstallAndRemoveTimer;
}
}
asciidoc.install();
/*]]>*/
</script>
</head>
<body class="article">
<div id="header">
<h1>parse-options API</h1>
</div>
<div id="content">
<div id="preamble">
<div class="sectionbody">
<div class="paragraph"><p>The parse-options API is used to parse and massage options in Git
and to provide a usage help with consistent look.</p></div>
</div>
</div>
<div class="sect1">
<h2 id="_basics">Basics</h2>
<div class="sectionbody">
<div class="paragraph"><p>The argument vector <code>argv[]</code> may usually contain mandatory or optional
<em>non-option arguments</em>, e.g. a filename or a branch, and <em>options</em>.
Options are optional arguments that start with a dash and
that allow to change the behavior of a command.</p></div>
<div class="ulist"><ul>
<li>
<p>
There are basically three types of options:
<em>boolean</em> options,
options with (mandatory) <em>arguments</em> and
options with <em>optional arguments</em>
(i.e. a boolean option that can be adjusted).
</p>
</li>
<li>
<p>
There are basically two forms of options:
<em>Short options</em> consist of one dash (<code>-</code>) and one alphanumeric
character.
<em>Long options</em> begin with two dashes (<code>--</code>) and some
alphanumeric characters.
</p>
</li>
<li>
<p>
Options are case-sensitive.
Please define <em>lower-case long options</em> only.
</p>
</li>
</ul></div>
<div class="paragraph"><p>The parse-options API allows:</p></div>
<div class="ulist"><ul>
<li>
<p>
<em>sticked</em> and <em>separate form</em> of options with arguments.
<code>-oArg</code> is sticked, <code>-o Arg</code> is separate form.
<code>--option=Arg</code> is sticked, <code>--option Arg</code> is separate form.
</p>
</li>
<li>
<p>
Long options may be <em>abbreviated</em>, as long as the abbreviation
is unambiguous.
</p>
</li>
<li>
<p>
Short options may be bundled, e.g. <code>-a -b</code> can be specified as <code>-ab</code>.
</p>
</li>
<li>
<p>
Boolean long options can be <em>negated</em> (or <em>unset</em>) by prepending
<code>no-</code>, e.g. <code>--no-abbrev</code> instead of <code>--abbrev</code>. Conversely,
options that begin with <code>no-</code> can be <em>negated</em> by removing it.
</p>
</li>
<li>
<p>
Options and non-option arguments can clearly be separated using the <code>--</code>
option, e.g. <code>-a -b --option -- --this-is-a-file</code> indicates that
<code>--this-is-a-file</code> must not be processed as an option.
</p>
</li>
</ul></div>
</div>
</div>
<div class="sect1">
<h2 id="_steps_to_parse_options">Steps to parse options</h2>
<div class="sectionbody">
<div class="olist arabic"><ol class="arabic">
<li>
<p>
<code>#include "parse-options.h"</code>
</p>
</li>
<li>
<p>
define a NULL-terminated
<code>static const char * const builtin_foo_usage[]</code> array
containing alternative usage strings
</p>
</li>
<li>
<p>
define <code>builtin_foo_options</code> array as described below
in section <em>Data Structure</em>.
</p>
</li>
<li>
<p>
in <code>cmd_foo(int argc, const char **argv, const char *prefix)</code>
call
</p>
<div class="literalblock">
<div class="content">
<pre><code>argc = parse_options(argc, argv, prefix, builtin_foo_options, builtin_foo_usage, flags);</code></pre>
</div></div>
<div class="paragraph"><p><code>parse_options()</code> will filter out the processed options of <code>argv[]</code> and leave the
non-option arguments in <code>argv[]</code>.
<code>argc</code> is updated appropriately because of the assignment.</p></div>
<div class="paragraph"><p>You can also pass NULL instead of a usage array as the fifth parameter of
parse_options(), to avoid displaying a help screen with usage info and
option list. This should only be done if necessary, e.g. to implement
a limited parser for only a subset of the options that needs to be run
before the full parser, which in turn shows the full help message.</p></div>
<div class="paragraph"><p>Flags are the bitwise-or of:</p></div>
<div class="dlist"><dl>
<dt class="hdlist1">
<code>PARSE_OPT_KEEP_DASHDASH</code>
</dt>
<dd>
<p>
Keep the <code>--</code> that usually separates options from
non-option arguments.
</p>
</dd>
<dt class="hdlist1">
<code>PARSE_OPT_STOP_AT_NON_OPTION</code>
</dt>
<dd>
<p>
Usually the whole argument vector is massaged and reordered.
Using this flag, processing is stopped at the first non-option
argument.
</p>
</dd>
<dt class="hdlist1">
<code>PARSE_OPT_KEEP_ARGV0</code>
</dt>
<dd>
<p>
Keep the first argument, which contains the program name. It’s
removed from argv[] by default.
</p>
</dd>
<dt class="hdlist1">
<code>PARSE_OPT_KEEP_UNKNOWN</code>
</dt>
<dd>
<p>
Keep unknown arguments instead of erroring out. This doesn’t
work for all combinations of arguments as users might expect
it to do. E.g. if the first argument in <code>--unknown --known</code>
takes a value (which we can’t know), the second one is
mistakenly interpreted as a known option. Similarly, if
<code>PARSE_OPT_STOP_AT_NON_OPTION</code> is set, the second argument in
<code>--unknown value</code> will be mistakenly interpreted as a
non-option, not as a value belonging to the unknown option,
the parser early. That’s why parse_options() errors out if
both options are set.
</p>
</dd>
<dt class="hdlist1">
<code>PARSE_OPT_NO_INTERNAL_HELP</code>
</dt>
<dd>
<p>
By default, parse_options() handles <code>-h</code>, <code>--help</code> and
<code>--help-all</code> internally, by showing a help screen. This option
turns it off and allows one to add custom handlers for these
options, or to just leave them unknown.
</p>
</dd>
</dl></div>
</li>
</ol></div>
</div>
</div>
<div class="sect1">
<h2 id="_data_structure">Data Structure</h2>
<div class="sectionbody">
<div class="paragraph"><p>The main data structure is an array of the <code>option</code> struct,
say <code>static struct option builtin_add_options[]</code>.
There are some macros to easily define options:</p></div>
<div class="dlist"><dl>
<dt class="hdlist1">
<code>OPT__ABBREV(&int_var)</code>
</dt>
<dd>
<p>
Add <code>--abbrev[=<n>]</code>.
</p>
</dd>
<dt class="hdlist1">
<code>OPT__COLOR(&int_var, description)</code>
</dt>
<dd>
<p>
Add <code>--color[=<when>]</code> and <code>--no-color</code>.
</p>
</dd>
<dt class="hdlist1">
<code>OPT__DRY_RUN(&int_var, description)</code>
</dt>
<dd>
<p>
Add <code>-n, --dry-run</code>.
</p>
</dd>
<dt class="hdlist1">
<code>OPT__FORCE(&int_var, description)</code>
</dt>
<dd>
<p>
Add <code>-f, --force</code>.
</p>
</dd>
<dt class="hdlist1">
<code>OPT__QUIET(&int_var, description)</code>
</dt>
<dd>
<p>
Add <code>-q, --quiet</code>.
</p>
</dd>
<dt class="hdlist1">
<code>OPT__VERBOSE(&int_var, description)</code>
</dt>
<dd>
<p>
Add <code>-v, --verbose</code>.
</p>
</dd>
<dt class="hdlist1">
<code>OPT_GROUP(description)</code>
</dt>
<dd>
<p>
Start an option group. <code>description</code> is a short string that
describes the group or an empty string.
Start the description with an upper-case letter.
</p>
</dd>
<dt class="hdlist1">
<code>OPT_BOOL(short, long, &int_var, description)</code>
</dt>
<dd>
<p>
Introduce a boolean option. <code>int_var</code> is set to one with
<code>--option</code> and set to zero with <code>--no-option</code>.
</p>
</dd>
<dt class="hdlist1">
<code>OPT_COUNTUP(short, long, &int_var, description)</code>
</dt>
<dd>
<p>
Introduce a count-up option.
<code>int_var</code> is incremented on each use of <code>--option</code>, and
reset to zero with <code>--no-option</code>.
</p>
</dd>
<dt class="hdlist1">
<code>OPT_BIT(short, long, &int_var, description, mask)</code>
</dt>
<dd>
<p>
Introduce a boolean option.
If used, <code>int_var</code> is bitwise-ored with <code>mask</code>.
</p>
</dd>
<dt class="hdlist1">
<code>OPT_NEGBIT(short, long, &int_var, description, mask)</code>
</dt>
<dd>
<p>
Introduce a boolean option.
If used, <code>int_var</code> is bitwise-anded with the inverted <code>mask</code>.
</p>
</dd>
<dt class="hdlist1">
<code>OPT_SET_INT(short, long, &int_var, description, integer)</code>
</dt>
<dd>
<p>
Introduce an integer option.
<code>int_var</code> is set to <code>integer</code> with <code>--option</code>, and
reset to zero with <code>--no-option</code>.
</p>
</dd>
<dt class="hdlist1">
<code>OPT_SET_PTR(short, long, &ptr_var, description, ptr)</code>
</dt>
<dd>
<p>
Introduce a boolean option.
If used, set <code>ptr_var</code> to <code>ptr</code>.
</p>
</dd>
<dt class="hdlist1">
<code>OPT_STRING(short, long, &str_var, arg_str, description)</code>
</dt>
<dd>
<p>
Introduce an option with string argument.
The string argument is put into <code>str_var</code>.
</p>
</dd>
<dt class="hdlist1">
<code>OPT_INTEGER(short, long, &int_var, description)</code>
</dt>
<dd>
<p>
Introduce an option with integer argument.
The integer is put into <code>int_var</code>.
</p>
</dd>
<dt class="hdlist1">
<code>OPT_DATE(short, long, &int_var, description)</code>
</dt>
<dd>
<p>
Introduce an option with date argument, see <code>approxidate()</code>.
The timestamp is put into <code>int_var</code>.
</p>
</dd>
<dt class="hdlist1">
<code>OPT_CALLBACK(short, long, &var, arg_str, description, func_ptr)</code>
</dt>
<dd>
<p>
Introduce an option with argument.
The argument will be fed into the function given by <code>func_ptr</code>
and the result will be put into <code>var</code>.
See <em>Option Callbacks</em> below for a more elaborate description.
</p>
</dd>
<dt class="hdlist1">
<code>OPT_FILENAME(short, long, &var, description)</code>
</dt>
<dd>
<p>
Introduce an option with a filename argument.
The filename will be prefixed by passing the filename along with
the prefix argument of <code>parse_options()</code> to <code>prefix_filename()</code>.
</p>
</dd>
<dt class="hdlist1">
<code>OPT_ARGUMENT(long, description)</code>
</dt>
<dd>
<p>
Introduce a long-option argument that will be kept in <code>argv[]</code>.
</p>
</dd>
<dt class="hdlist1">
<code>OPT_NUMBER_CALLBACK(&var, description, func_ptr)</code>
</dt>
<dd>
<p>
Recognize numerical options like -123 and feed the integer as
if it was an argument to the function given by <code>func_ptr</code>.
The result will be put into <code>var</code>. There can be only one such
option definition. It cannot be negated and it takes no
arguments. Short options that happen to be digits take
precedence over it.
</p>
</dd>
<dt class="hdlist1">
<code>OPT_COLOR_FLAG(short, long, &int_var, description)</code>
</dt>
<dd>
<p>
Introduce an option that takes an optional argument that can
have one of three values: "always", "never", or "auto". If the
argument is not given, it defaults to "always". The <code>--no-</code> form
works like <code>--long=never</code>; it cannot take an argument. If
"always", set <code>int_var</code> to 1; if "never", set <code>int_var</code> to 0; if
"auto", set <code>int_var</code> to 1 if stdout is a tty or a pager,
0 otherwise.
</p>
</dd>
<dt class="hdlist1">
<code>OPT_NOOP_NOARG(short, long)</code>
</dt>
<dd>
<p>
Introduce an option that has no effect and takes no arguments.
Use it to hide deprecated options that are still to be recognized
and ignored silently.
</p>
</dd>
</dl></div>
<div class="paragraph"><p>The last element of the array must be <code>OPT_END()</code>.</p></div>
<div class="paragraph"><p>If not stated otherwise, interpret the arguments as follows:</p></div>
<div class="ulist"><ul>
<li>
<p>
<code>short</code> is a character for the short option
(e.g. <code>'e'</code> for <code>-e</code>, use <code>0</code> to omit),
</p>
</li>
<li>
<p>
<code>long</code> is a string for the long option
(e.g. <code>"example"</code> for <code>--example</code>, use <code>NULL</code> to omit),
</p>
</li>
<li>
<p>
<code>int_var</code> is an integer variable,
</p>
</li>
<li>
<p>
<code>str_var</code> is a string variable (<code>char *</code>),
</p>
</li>
<li>
<p>
<code>arg_str</code> is the string that is shown as argument
(e.g. <code>"branch"</code> will result in <code><branch></code>).
If set to <code>NULL</code>, three dots (<code>...</code>) will be displayed.
</p>
</li>
<li>
<p>
<code>description</code> is a short string to describe the effect of the option.
It shall begin with a lower-case letter and a full stop (<code>.</code>) shall be
omitted at the end.
</p>
</li>
</ul></div>
</div>
</div>
<div class="sect1">
<h2 id="_option_callbacks">Option Callbacks</h2>
<div class="sectionbody">
<div class="paragraph"><p>The function must be defined in this form:</p></div>
<div class="literalblock">
<div class="content">
<pre><code>int func(const struct option *opt, const char *arg, int unset)</code></pre>
</div></div>
<div class="paragraph"><p>The callback mechanism is as follows:</p></div>
<div class="ulist"><ul>
<li>
<p>
Inside <code>func</code>, the only interesting member of the structure
given by <code>opt</code> is the void pointer <code>opt->value</code>.
<code>*opt->value</code> will be the value that is saved into <code>var</code>, if you
use <code>OPT_CALLBACK()</code>.
For example, do <code>*(unsigned long *)opt->value = 42;</code> to get 42
into an <code>unsigned long</code> variable.
</p>
</li>
<li>
<p>
Return value <code>0</code> indicates success and non-zero return
value will invoke <code>usage_with_options()</code> and, thus, die.
</p>
</li>
<li>
<p>
If the user negates the option, <code>arg</code> is <code>NULL</code> and <code>unset</code> is 1.
</p>
</li>
</ul></div>
</div>
</div>
<div class="sect1">
<h2 id="_sophisticated_option_parsing">Sophisticated option parsing</h2>
<div class="sectionbody">
<div class="paragraph"><p>If you need, for example, option callbacks with optional arguments
or without arguments at all, or if you need other special cases,
that are not handled by the macros above, you need to specify the
members of the <code>option</code> structure manually.</p></div>
<div class="paragraph"><p>This is not covered in this document, but well documented
in <code>parse-options.h</code> itself.</p></div>
</div>
</div>
<div class="sect1">
<h2 id="_examples">Examples</h2>
<div class="sectionbody">
<div class="paragraph"><p>See <code>test-parse-options.c</code> and
<code>builtin-add.c</code>,
<code>builtin-clone.c</code>,
<code>builtin-commit.c</code>,
<code>builtin-fetch.c</code>,
<code>builtin-fsck.c</code>,
<code>builtin-rm.c</code>
for real-world examples.</p></div>
</div>
</div>
</div>
<div id="footnotes"><hr /></div>
<div id="footer">
<div id="footer-text">
Last updated 2013-06-10 20:01:55 UTC
</div>
</div>
</body>
</html>