Using strftime function in mawk

Question

I'm trying to create AWK script that will filter the input file according to some pattern, and use the strftime() function for some calculations.

($2 ~ /^[HB]/ && $2 ~ /n$/){
        print strftime("%Y")
}

The interpreter in use is mawk. When triggering this script using this command:

awk -f script3 inputFile

I'm getting the error: "function strftime never defined"

Answer 1

Well, clearly, mawk does not have a strftime function.

I don't have mawk here, so untested:

awk -f script -v the_year=$(date "+%Y") inputFile

and script has (combining the two regular expressions:

$2 ~ /^[HB].*n$/ { print the_year }

If the year should come from $0 somehow, then you should be able to parse it out of the string. Give us more details about your input.

EDIT

the input is made of several rows that look like this: "12768 Ashwari F 20 11 1985". Basically I have to filter all those with a name that begins with B or H and ends with n. In addition I have to calculate the age of each filtered student and find out the average age of the entire group.

awk -v this_year=$(date +%Y) -v today=$(date +%Y%m%d) '
    $2 ~ /^[BH].*n$/ {
        age = this_year - $6
        if (today < $6 $5 $4) { age-- } # I assume those fields are the birthday 
        total_age += age
        count ++
        print $2 " is " age " years old"
    }
    END {
        print "average age = " total_age/count
    }
' inputFile