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→INVESTIGATION 2: EXTENDED REGULAR EXPRESSIONS
# Issue the following linux pipeline command to download another data file called '''words.dat''':<br><span style="color:blue;font-weight:bold;font-family:courier;">wget <nowiki>https://ict.senecacollege.ca/~murray.saul/uli101/words.dat</nowiki></span><br><br>
# View the contents of the '''words.dat''' file using the '''more''' command and quickly view the contents of this file.<br>You should notice valid and more invalid numbers contained in this file. When finished, exit the more command.<br><br>
# Issue the following linux pipeline command to display two or more occurrences of the word "the":<br><span style="color:blue;font-weight:bold;font-family:courier;">egrep -i "(the){2,}" words.dat | tee word-search1.txt more</span><br><br>'''NOTE:''' You should '''NOT see any output '''<br><br>This is due to the fact that a <u>space</u> should be included at the end of the word "'''the'''".<br>Usually words are separated by spaces; therefore, there were no matches since there were not occurrences<br>of "thethe" as opposed to "'''the the'''" (i.e. no space after repetition of the pattern).<br><br>
# Reissue the previous pipeline command including a space in brackets:<br><span style="color:blue;font-weight:bold;font-family:courier;">egrep -i "(the ){2,}" words.dat | tee word-search2.txt</span><br><br>The "|" (or) symbol can be used within the grouping symbols to allow matching of additional groups of characters.<br>Again, it is important to follow the character groupings with the space character<br><br>
# Issue the following linux pipeline command to search for 2 or more occurrences of the word "'''the'''" <u>or</u> the word "'''and'''":<br><span style="color:blue;font-weight:bold;font-family:courier;">egrep -i "(the |and ){2,}" words.dat | tee word-search3.txt</span><br><br>
