What does `args` in Linux command `ps ao args` means exactly? : <p>In the man page of <code>ps</code>, I found that <code>-a</code> means:</p>

<blockquote>
  <p>Select all processes except both session leaders (see getsid(2)) and
  processes not associated with a terminal.</p>
</blockquote>

<p>and <code>-o</code> means</p>

<blockquote>
  <p>User-defined format.  format is a single argument in the form of a blank-separated or comma-separated list, which offers a way to specify individual output columns.  The recognized keywords are described in the STANDARD FORMAT SPECIFIERS section below. Headers may be renamed (ps -o pid,ruser=RealUser -o comm=Command) as desired.  If all column headers are empty (ps -o pid=-o comm=) then the header line will not be output.  Column width will increase as needed for wide headers; this may be used to widen up columns such as WCHAN (ps -o pid,wchan=WIDE-WCHAN-COLUMN -o comm).  Explicit width control (ps opid,wchan:42,cmd) is offered too.  The behavior of ps -o pid=X,comm=Y varies with personality; output may be one column named "X,comm=Y" or two columns named "X" and "Y".  Use multiple -o options when in doubt.  Use the PS_FORMAT environment variable to specify a default as desired; DefSysV and DefBSD are macros that may be used to choose the default UNIX or BSD columns.</p>
</blockquote>

<p>But what does the <code>args</code> means in this command?</p>

<p>Note the <code>args</code> is not a placeholder for anything else, just 4 chars: <code>a</code>+<code>r</code>+<code>g</code>+<code>s</code></p>
