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>

'''<span style="font-family:courier;font-weight:bold">ls -l<br>ls -l > detailed-listing.txt<br>ls /bin >> output.txt'''</span>