title: Various flags in bash
body: <p>I see many times flags such as <code>if [-n ${Parameter}]</code> or <code>echo -n &lt;string&gt;</code>. Sometimes, I have seen flags like <code>-r</code> and others used. However, I don't know how to search for the meaning of these flags on web. Could someone send me some link where I can understand as to what they mean or some general note as to how should I search for them on google? Thanks!</p>