Countif like function in AWK with field headers - awk

Question

I am looking for a way of counting the number of times a value in a field appears in a range of fields in a csv file much the same as countif in excel although I would like to use an awk command if possible.
So column 6 should have the range of values and column 7 would have the times the value appears in column 7, as per below
>awk -F, '{print $0}' file3
f1,f2,f3,f4,f5,test
row1_1,row1_2,row1_3,SBCDE,row1_5,SBCD
row2_1,row2_2,row2_3,AWERF,row2_5,AWER
row3_1,row3_2,row3_3,ASDFG,row3_5,ASDF
row4_1,row4_2,row4_3,PRE-ASDQG,row4_5,ASDQ
row4_1,row4_2,row4_3,PRE-ASDQF,row4_5,ASDQ
>awk -F, '{print $6}' file3
test
SBCD
AWER
ASDF
ASDQ
ASDQ
What i want is:
f1,f2,f3,f4,f5,test,count
row1_1,row1_2,row1_3,SBCDE,row1_5,SBCD,1
row2_1,row2_2,row2_3,AWERF,row2_5,AWER,1
row3_1,row3_2,row3_3,ASDFG,row3_5,ASDF,1
row4_1,row4_2,row4_3,PRE-ASDQG,row4_5,ASDQ,2
row4_1,row4_2,row4_3,PRE-ASDQF,row4_5,ASDQ,2
#adds field name count that I want:
awk -F, -v OFS=, 'NR==1{ print $0, "count"}
NR>1{ print $0}' file3
Ho do I get the output I want?
I have tried this from previous/similar question but no joy,
>awk -F, 'NR>1{c[$6]++;l[NR>1]=$0}END{for(i=0;i++<NR;){split(l[i],s,",");print l[i]","c[s[1]]}}' file3
row4_1,row4_2,row4_3,PRE-ASDQF,row4_5,ASDQ,
,
,
,
,
,
very similar question to this one
similar python related Q, for my ref

Answer 1

I would harness GNU AWK for this task following way, let file.txt content be
f1,f2,f3,f4,f5,test
row1_1,row1_2,row1_3,SBCDE,row1_5,SBCD
row2_1,row2_2,row2_3,AWERF,row2_5,AWER
row3_1,row3_2,row3_3,ASDFG,row3_5,ASDF
row4_1,row4_2,row4_3,PRE-ASDQG,row4_5,ASDQ
row4_1,row4_2,row4_3,PRE-ASDQF,row4_5,ASDQ
then
awk 'BEGIN{FS=OFS=","}NR==1{print $0,"count";next}FNR==NR{arr[$6]+=1;next}FNR>1{print $0,arr[$6]}' file.txt file.txt
gives output
f1,f2,f3,f4,f5,test,count
row1_1,row1_2,row1_3,SBCDE,row1_5,SBCD,1
row2_1,row2_2,row2_3,AWERF,row2_5,AWER,1
row3_1,row3_2,row3_3,ASDFG,row3_5,ASDF,1
row4_1,row4_2,row4_3,PRE-ASDQG,row4_5,ASDQ,2
row4_1,row4_2,row4_3,PRE-ASDQF,row4_5,ASDQ,2
Explanation: this is two-pass approach, hence file.txt appears twice. I inform GNU AWK that , is both field separator (FS) and output field separator (OFS), then for first line (header) I print it followed by count and instruct GNU AWK to go to next line, so nothing other is done regarding 1st line, then for first pass, i.e. where global number of line (NR) is equal to number of line in file (FNR) I count number of occurences of values in 6th field and store them as values in array arr, then instruct GNU AWK to get to next line, so onthing other is done in this pass. During second pass for all lines after 1st (FNR>1) I print whole line ($0) followed by corresponding value from array arr
(tested in GNU Awk 5.0.1)

Answer 2

You did not copy the code from the linked question properly. Why change l[NR] to l[NR>1] at all? On the other hand, you should change s[1] to s[6] since it's the sixth field that has the key you're counting:
awk -F, 'NR>1{c[$6]++;l[NR]=$0}END{for(i=0;i++<NR;){split(l[i],s,",");print l[i]","c[s[6]]}}'
You can also output the header with the new field name:
awk -F, -vOFS=, 'NR==1{print $0,"count"}NR>1{c[$6]++;l[NR]=$0}END{for(i=0;i++<NR;){split(l[i],s,",");print l[i],c[s[6]]}}'

Answer 3

One awk idea:
awk '
BEGIN { FS=OFS="," } # define input/output field delimiters as comma
{ lines[NR]=$0
if (NR==1) next
col6[NR]=$6 # copy field 6 so we do not have to parse the contents of lines[] in the END block
cnt[$6]++
}
END { for (i=1;i<=NR;i++)
print lines[i], (i==1 ? "count" : cnt[col6[i]] )
}
' file3
This generates:
f1,f2,f3,f4,f5,test,count
row1_1,row1_2,row1_3,SBCDE,row1_5,SBCD,1
row2_1,row2_2,row2_3,AWERF,row2_5,AWER,1
row3_1,row3_2,row3_3,ASDFG,row3_5,ASDF,1
row4_1,row4_2,row4_3,PRE-ASDQG,row4_5,ASDQ,2
row4_1,row4_2,row4_3,PRE-ASDQF,row4_5,ASDQ,2