Changes

<span style="font-family:courier;font-weight:bold">tr 'a-z' 'A-Z' < words.txt<br>cat < abc.txt<br>sort < xyz.txt</span>

<table align="right"><tr><td>[[Image:stdout-symbol-1.png|thumb|right|250px|The '''standard input''' ('''stdin''') symbol with one greater than sign overwrites existing file content with command output]]</td><td>[[Image:stdout-symbol-2.png|thumb|right|250px|The '''standard input''' ('''stdin''') symbol with two greater than signs add command's output to bottom of existing file's contents.]]</td></tr></table>