1) counting words
cat /usr/share/dict/words | wc -l
2) counting characters
cat /usr/share/dict/words | wc -c
3) replacing the ‘enter’ or ‘newline’ with comma
cat /usr/share/dict/words | tail -7 | tr '\n' ','
zymotoxic,zymurgy,Zyrenian,Zyrian,Zyryan,zythem,Zythia,
4) replacing more than a single character
cat /usr/share/dict/words | tail -7 | sed 's/Zy/Baaa/'
zymotoxic,zymurgy,Zyrenian,Zyrian,Zyryan,zythem,Zythia,
Teaching Kids Programming 
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