[awk] Sum the values of a column, based on the values of another column

 Using awk to sum the values of a column, based on the values of another column

 

Q. I am trying to sum certain numbers in a column using awk. I would like to sum just column 3 of the "smiths" to get a total of 212. I can sum the whole column using awk but not just the "smiths". I have:

awk 'BEGIN {FS = "|"} ; {sum+=$3} END {print sum}' filename.txt

Also I am using putty. Thank you for any help.

smiths|Login|2
olivert|Login|10
denniss|Payroll|100
smiths|Time|200
smiths|Logout|10

A.

awk -F '|' '$1 ~ /smiths/ {sum += $3} END {print sum}' inputfilename

• The -F flag sets the field separator; I put it in single quotes because it is a special shell character.
• Then $1 ~ /smiths/ applies the following {code block} only to lines where the first field matches the regex /smiths/.
• The rest is the same as your code.

Note that since you're not really using a regex here, just a specific value, you could just as easily use:

awk -F '|' '$1 == "smiths" {sum += $3} END {print sum}' inputfilename

Which checks string equality. This is equivalent to using the regex /^smiths$/, as mentioned in another answer, which includes the ^ anchor to only match the start of the string (the start of field 1) and the $ anchor to only match the end of the string. Not sure how familiar you are with regexes. They are very powerful, but for this case you could use a string equality check just as easily.