Using Linux command: awk to sum up a list of number

Linux Command Line
AWK

Example
> cat Text.txt
1
2
3
4
5

If you want to get the sum of this column, you can use the tool awk.
cat Text.txt | awk '{sum += $1} END {print sum}'

Output:
15

If you want to show the information of the file together with the sum, you can enter the command as below
cat Text.txt | awk '{sum += $1} {print} END {print sum}

Output:
1
2
3
4
5
15

---

AWK

The AWK utility is a data extraction and reporting tool

Wiki page: http://en.wikipedia.org/wiki/AWK

Reference: 

vbird:

http://linux.vbird.org/linux_basic/0330regularex.php
http://linux.vbird.org/linux_basic/0330regularex/awk.pdf