mjhjmtu

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

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.

Another approach is to use awk associative arrays, more info here. This line produces the desired output:

awk -F '|' 'a[$1] += $3 ENDprint a["smiths"]' filename.txt

As a side effect, the array stores all other values:

awk -F '|' 'a[$1] += $3 ENDfor (i in a) print i, a[i]' filename.txt

Output:

smiths 212
denniss 100
olivert 10

Very good so far. All you need to do is add a selector before the block to add the sum. Here we check that the first argument contains only "smiths":

awk 'BEGIN FS = " ; $1 ~ /^smiths$/ sum+=$3 END print sum'

You could shorten this a bit by specifying the field separator as an option. In awk it's generally a good idea to initialize variables on the command line:

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

cat filename.txt | grep smiths | awk -F '|' 'sum+=$NF END print sum'

• 
  -F option to specify separator.


• 
  $NF is for "last column".