Just for the interested reader: when the first command line is changed into

    pi:~$ echo 'foo  bar' | tr -s ' ' | cut -d ' ' -f 2

it also outputs 'bar'. The -s (for "squeeze") option of tr turns every sequence of the specified character (space in this case) into one instance of this character.

Of course, the awk solution is more succint and elegant in this case - I just think that tr -s / cut -d is handy to know from time to time, too.

The interested reader should not assume hastily, however, that tr -s is enough to make cut behave exactly like awk. Hint: leading spaces.

    pi:~$ echo ' foo' | tr -s ' ' | cut -d ' ' -f 1 
    
    pi:~$ echo ' foo' | awk '{print $1}'
    foo