wc(1) -l archivo01.txt
print newline, word, and byte counts for each file
-l, --lines
       print the newline counts
Print  newline, word, and byte counts for each FILE, and a total line if more than one FILE is specified.
With no FILE, or when FILE is -, read standard input.  A word is a non-zero-length sequence of characters
delimited  by  white  space.  The options below may be used to select which counts are printed, always in
the following order: newline, word, character, byte, maximum line length.
source manpages: wc