Look also at your book's description of basic regular expressions (BREs) for:Can you combine the above concepts to produce a BRE that is anchored to the start of a line (matches zero or more occurrences of characters that are not your field delimiter followed by your field delimiter) a specific number of times to skip over the contents of a specific number of fields at the start of a line?

For example, what do you think the BRE in the following grep command will match?

Code:

grep -n '^\([^:]*:\)\{4\}[^:]*\.edu:' smallFile

Try running that command. Did it print the lines you expected it to print?
What do you think the BRE in the following grep command will match?

Code:

grep -n '1$' smallFile

What happens if you combine the above two commands in a pipeline?

Code:

grep -n '^\([^:]*:\)\{4\}[^:]*\.edu:' smallFile | grep '1$'

What happens if you use a single grep to search for both BREs?

Code:

grep -n -e '^\([^:]*:\)\{4\}[^:]*\.edu:' -e '1$' smallFile

Does one of the above two suggestions provide a logical OR of the two BREs? Does one of the above two suggestions provide a logical AND of the two BREs?