How to quickly sum all numbers in a file

You can take help from paste to serialize the numbers in a format suitable for bc to do the addition:

% grep "30201" logfile.txt | cut -f6 -d "|"
650
1389
945

% grep "30201" logfile.txt | cut -f6 -d "|" | paste -sd+
650+1389+945

% grep "30201" logfile.txt | cut -f6 -d "|" | paste -sd+ | bc
2984

If you have grep with PCRE, you can do it with grep alone using postive lookbehind:

% grep -Po '\|30201\|.*\|\K\d+' logfile.txt | cut -f6 -d "|" | paste -sd+ | bc
2984

With awk alone:

% awk -F'|' '$3 == 30201 {sum+=$NF}; END{print sum}' logfile.txt        
2984

• -F'|' sets the field separator as |
• $3 == 30201 {sum+=$NF} adds up the last field's values if the third field is 30201
• END{print sum} prints the sum at the END

Assuming that every line has the same number of fields (columns):

awk '
    NR==1   { for (i=1; i<=NF; i++) header[i]=$i; next; }
            { for (i=1; i<=NF; i++) total[i] += $i; }
    END     { for (i=1; i<=NF; i++) print header[i] "=" total[i]+0 }
    '

Sample input:

red green blue
1 2 4
8 16 32
64 128 256

Corresponding output:

red=73
green=146
blue=292