matching columns one separate files and appending matches to file - awk

Question

I'm trying to merge two files filtered on a single column using awk. What I'd then like to do is append the relevant columns from file2 into file 1.
Easier to explain with dummy example.
File1
name fruit animal
bob apple dog
jim orange cat
gary mango snake
daisy peach mouse
File 2:
animal number shape
cat eight square
dog nine circle
mouse eleven sphere
Desired output:
name fruit animal shape
bob apple dog circle
jim orange cat square
gary mango snake NA
daisy peach mouse sphere
Step 1: Need to filter on column 3 in file1 and column 1 in file2
awk -F'\t' 'NR==FNR{c[$3]++;next};c[$1] > 0' file1 file2
This gives me output:
cat eight square
dog nine circle
mouse eleven sphere
This helps me somewhat, however I can't simply cut the third column (shape) from the output above and append it to to file1 since there is no entry for 'snake' in file2. I need to be able to append column 3 of output to file 1 where a match is successful, and where it is not to put 'NA'. It's essential that all the lines in file1 are retained so I can't just omit them. This is where I'm stuck!
I'd appreciate any help please....
E

Answer 1

Could you please try following, written and tested based on shown samples in GNU awk.
awk '
BEGIN{
OFS="\t"
}
FNR==NR{
a[$1]=$NF
next
}
{
print $0,($3 in a?a[$3]:"NA")
}' Input_file2 Input_file1
Explanation: Adding detailed explanation for above.
awk ' ##Starting awk program from here.
BEGIN{ ##Starting BEGIN section from here.
OFS="\t" ##Setting TAB as output field separator here.
}
FNR==NR{ ##Checking condition FNR==NR which will be TRUE when first Input_file file2 is being read.
a[$1]=$NF ##Creating array a with index $1 and value is $NF for current line.
next ##next will skip all further statements from here.
}
{
print $0,($3 in a?a[$3]:"NA") ##Printing current line and checking if 3rd field is present in array a then print its value OR print NA.
}' file2 file1 ##Mentioning Input_file names here.