[SOLVED] AWK Filter Items from 3 Lists

blumenwesen · 02-04-2024, 12:26 AM

Hello, my experiment with AWK The versed lines from the comparison of List2 and List1 1 again by filtering exceptions from List 3 gives me the following:

Code:

awk 'NR==FNR{z[$0]++; next} !($0 in z) || !($0 in y)' y="$(echo -e "x\ny")" <(echo -e "a\nb") <(echo -e "a\nb\nc\nx\ny\nz")

awk: (FILENAME=/dev/fd/62 FNR=1) fatal: attempt to use a scalar value as field

This is what the result should look like:

Quote:

c
z

Turbocapitalist · 02-04-2024, 02:13 AM

Is the variable y going to keep changing with each pass through the loop or will it stay the same for the duration of the script? If it stays the same then you can use --assign to read it in and split() to break it into an array.

pan64 · 02-04-2024, 04:05 AM

Code:

awk -v y="$(....)" 'NR==......'

If I understand it well -v is missing

grail · 02-04-2024, 04:30 AM

Setting the variable is fine, but as the error message has advised, 'y' is not an array and hence you cannot use the 'in' test on a scalar variable

blumenwesen · 02-04-2024, 07:22 PM

I misrepresented it yesterday before sleeping, meant that the lines from list3 must not be added but subsequently from the result of the deduction of list2 from list1.
Is there an easier way within a single awk call?

Code:

awk 'NR==FNR{z[$0]++; next} !($0 in z)' <(echo -e "c\nf") <(awk 'NR==FNR{z[$0]++; next} !($0 in z)' <(echo -e "a\nb\nc\nd") <(echo -e "a\nb\nc\nd\ne\nf"))
>>d
>>e

blumenwesen · 02-04-2024, 09:53 PM

Now the chaos could no longer withstand my superior mind. =D
Thanks for help

Code:

awk -v z="$(echo -e "a\nf")" 'BEGIN{y=split(z, x, "\n"); for(w=1; w<=y; w++){v[x[w]]}} NR==FNR{u[$0]++; next} {if(!($0 in u) && !($0 in v)){print $0}}' <(echo -e "a\nb\ne\nf") <(echo -e "a\nb\nc\nd\ne\nf")
>>c
>>d

MadeInGermany · 02-06-2024, 02:19 PM

A[$0]=1 or A[$0]++ assign a value to the array member. awk allows to omit the value, just define the index: A[$0]

awk has no means to pass an array as an argument. Passing a string then BEGIN split into an array - ok.
The following works with files only.
Also it reads the total list first, then eliminates from the following files. (So you could easily add more files.)

Code:

awk 'NR == FNR { A[$0]; next } { delete A[$0] } END { for (a in A) print a }' <(echo -e "a\nb\nc\nd\ne\nf") <(echo -e "a\nf") <(echo -e "a\nb\ne\nf")

c
d