Shell – printf, awk … How to format a number with space to the thousands

You can try this:

$ awk 'BEGIN{printf "%3.0f\n", 3.6}'
  4

Our format option has two parts:

• 3: meaning output will be padded to 3 characters.
• .0f: meaning output will have no precision, meaning rounded up.

From man awk, you can see more details:

width   The field should be padded to this width. The field is normally padded
        with spaces. If the 0  flag  has  been  used, it is padded with zeroes.

.prec   A number that specifies the precision to use when printing.  For the %e,
        %E, %f and %F, formats, this specifies the number of digits you want
        printed to the right of the decimal point. For the %g, and %G formats,
        it specifies the maximum number of significant  digits. For the %d, %o,
        %i, %u, %x, and %X formats, it specifies the minimum number of digits to
        print. For %s, it specifies the maximum number of characters from the
        string that should be printed.

You can count the unique columns with following pipe:

$ awk '{for (i=1; i<=NF; ++i) a[i]=a[i]$i; } END { for (i in a) print a[i] }' foo \
  | sort -u | wc -l

The awk command transposes your input, the resulting lines are sorted, only unique lines are kept (-u) and at the end all (unique) lines (i.e. the transposed columns) are counted (wc -l).

Note that NF is a builtin awk variable and is automatically set to the number of fields in the current record. $i references the i-th field and END guards the following block such that it is executed after all records are processed. Awk uses by default blank-non-blank field delimiting.