Shell Programming and Scripting

servername1,patchid1
servername1,patchid2
servername1,patchid3
servername2,patchid1
servername2,patchid2
servername3,patchid4
servername3,patchid5

servername1,appname1
servername1,appname2
servername1,appname3
servername2,appname1
servername2,appname2
servername2,appname3
servername2,appname4
servername3,appname10

servername1,patchid1,appname1
servername1,patchid1,appname2
servername1,patchid1,appname3
servername1,patchid2,appname1
servername1,patchid2,appname2
servername1,patchid2,appname3
servername1,patchid3,appname1
servername1,patchid3,appname2
servername1,patchid3,appname2
servername2,patchid1,appname1
servername2,patchid1,appname2
servername2,patchid1,appname3
servername2,patchid2,appname1
servername2,patchid2,appname2
servername2,patchid2,appname3
.....
....

$ awk  -F, 'FNR==NR{Arr[$1 FS NR]=$0;next}($1 FS FNR in Arr){print Arr[$1 FS FNR] FS $2}'  file2 file1 -- Wrong

$ awk -F, 'NR==FNR{Arr[$1 FS $2]=$1; next} {for (i in Arr) if($1==Arr[i]) print i,$2}' OFS=, file2 file1

servername1 patchid1,appname3
servername1 patchid2,appname3
servername1 patchid3,appname3
servername2 patchid1,appname4
servername2 patchid2,appname4
servername3 patchid4,appname10
servername3 patchid5,appname10

$ awk 'NR==FNR{A[$1 FS $2]=$1; next} {for (i in A) if($1==A[i]) print i,$2}' FS=, OFS=, file2 file1
servername1,appname1,patchid1
servername1,appname2,patchid1
servername1,appname3,patchid1
servername1,appname1,patchid2
servername1,appname2,patchid2
...

awk 'NR==FNR{A[$1 FS $2]=$1; next} {for (i in A) if($1==A[i]) {split(i,F); print $0,F[2]}}' FS=, OFS=, file2 file1

while IFS=, read f1a f1b
do
 while IFS=, read f2a f2b
 do
  [ "$f1a" = "$f2a" ] && echo "$f1a,$f1b,$f2b"
 done < file2
done < file1

tdir=./$$.tmp
mkdir $tdir || { echo use writable directory. ; exit ; }
while IFS=, read d1 d2
do
   mkdir -p $tdir/$d1/$d2
done < source1
while IFS=, read d3 d4
do
   for d5 in $tdir/$d3/*
   do
      [[ -d $d5 ]] && echo $d5/$d4 | sed 's/.*[.]tmp\///; s/\//,/g'
   done
done < source2
rm -rf $$.tmp