Display file contents,
cat <file_name>
View file contents page by page,
more <file_name>
Display the first few lines of a file,
head -n <number_of_lines> <file_name>
Display the last few lines of a file,
tail -n <number_of_lines> <file_name>
Search for a string in a file,
grep "<string>" <filename>
Extract specific fields from delimited text,
cut -d "<delimiter>" -f <field_number> <file_name>
Sort data,
sort <file_name>
Count words, lines, or characters.
wc <file_name>
Replace text strings
sed -i "s/<old_string>/<new_string>/g" <file_name>