/*! \page usage Usage

<pre>

jam [ -a ] [ -g ] [ -n ] [ -q ] [ -T ] [ -v ]

[ -b ]

[ -C <i>workdir</i> ]

[ -d <i>debug</i> ]

[ -f <i>jambase</i> ]

[ -j <i>jobs</i> ]

[ -o <i>actionsfile</i> ]

[ -r ]

[ -s <i>var</i>=<i>value</i> ]

[ -S ]

[ <i>var</i>=<i>value</i> ]

[ -t <i>target</i> ]

[ <i>target</i> ... ]

</pre>

If <i>target</i> is provided on the command line, <b>jam</b> builds <i>target</I>; otherwise <b>jam</b> builds the target 'all'.

<b>Jam</b> may be invoked with the following options:

<table width=85% align=center border=1 cellpadding=2>

<tr>

<td valign=top width=20%><code> -a </code>

<td> Build all targets anyway, even if they are up-to-date.

<tr>

<td valign=top><code> -b </code>

<td> Enables the Tilde Lua debugger and waits for a connection.

<tr>

<td valign=top><code> -C <i>workdir</i> </code>

<td> Set the \b Jam current working directory to \em workdir.

<tr>

<td valign=top><code> -d <i>c</i> </code>

<td> Turn on display option <i>c</i> and off the default display (summary info and actions):

<dl>

<dt> a <dd> Show summary info, actions, quiet actions, and the use of temporary targets

<dt> c <dd> Show the names of files that cause rebuilds, i.e. new sources, missing targets, etc.

<dt> d <dd> Display a dependency graph (in <b>jam</b> syntax).

<dt> f <dd> Display fate changes.

<dt> g <dd> Display a detailed hierarchical dependency graph.

<dt> m <dd> Display the dependency analysis, and target/source timestamps and paths

<dt> x <dd> Show shell arguments

</dl>

<tr>

<td valign=top><code> -d <i>n</i> </code>

<td> Enable cumulative debugging levels from 1 to <i>n</I>. Interesting values are:

<dl>

<dt> 1 <dd> Show actions and summary info (the default)

<dt> 2 <dd> Show text of actions

<dt> 3 <dd> Show progress of make. Show files when bound

<dt> 4 <dd> Show execcmd()'s work

<dt> 5 <dd> Show rule invocations and variable expansions

<dt> 6 <dd> Show directory/header file/archive scans

<dt> 7 <dd> Show variable settings

<dt> 8 <dd> Show variable fetches and expansions. Show 'if' calculations.

<dt> 9 <dd> Show variable manipulation, scanner tokens. Show memory use.

</dl>

<tr>

<td valign=top><code> -d +<I>n</i> </code>

<td> Enable debugging level <i>n</I>.

<tr>

<td valign=top><code> -d 0 </code>

<td> Turn off all debugging levels. Only errors are emitted.

<tr>

<td valign=top><code> -f <i>[-]Jamfile[.jam]</I></code>

<td>Read the built-in Jambase and then read <i>Jamfile.jam</i>. In order to bypass the built-in Jambase, preface the filename with a <tt>-<tt> (minus) symbol. Multiple -f flags are permitted. If <tt>.jam</tt> is not listed as the filename extension, it may be appended to the filename as part of the search.

<tr>

<td valign=top><code> -g </code>

<td> Build targets with the newest sources first, rather than in the order of appearance in the Jambase/Jamfiles.

<tr>

<td valign=top><code> -j <i>n</I></code>

<td> Run up to <i>n</i> shell commands concurrently. The default is the maximum number of available processors on the machine. On Windows, the number of processors is determined from the environment variable <tt>NUMBER_OF_PROCESSORS</tt>. On Mac OS X, the number of processors is obtained from the API <tt>MPProcessors</tt>.

<tr>

<td valign=top><code> -n</code>

<td> Don't actually execute the updating actions, but do everything else. This changes the debug level to -dax.

<tr>

<td valign=top><code> -o <i>file</I></code>

<td> Write the updating actions to the specified file instead of running them (or outputting them, as on the Mac).

<tr>

<td valign=top><code> -r </code>

<td> Enter run mode, a special mode that finds <b>jrun.jam</b> up the directory hierarchy and allows individual commands to be registered. See the <b>jrun.jam</b> top-level in the source tree for examples.

<tr>

<td valign=top><code> -q </code>

<td> Quit quickly (as if an interrupt was received) as soon as any target build fails.

<tr>

<td valign=top><code> -s <i>var</I>=<I>value</I></code>

<td> Set the variable <i>var</i> to <i>value</I>, overriding both internal variables and variables imported from the environment.

<tr>

<td valign=top><code> -S</code>

<td> When specified, any rules called that have not been defined are skipped without warning. <tt>jam --workspace</tt> makes extensive use of it. This command line option will mask problems with your Jamfiles, so it is recommended you don't use it.

<tr>

<td valign=top><code><i>var</I>=<I>value</I></code>

<td> Set the variable <i>var</i> to <i>value</I>, overriding both internal variables and variables imported from the environment. This is a simpler to use version of <tt>-s</tt>

<tr>

<td valign=top><code> -t <i>target</I></code>

<td> Rebuild <i>target</i> and everything that depends on it, even if it is up-to-date.

<tr>

<td valign=top><code> -T </code>

<td> Toggle printing of the target's bound name (full path).

<tr>

<td valign=top><code> -v</code>

<td> Print the version of <b>jam</b> and exit.

</table>

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