Below is the scenario. Help is appreciated.

File1: ( 500,000 lines ) : Three fields comma delimited : Not sorted

1234FAA,435612,88975
1224FAB,12345,212356


File2: ( 4,000,000 lines ) : Six fields comma delimited (Last 3 field should match the 3 fields of File1) : Not Sorted :

0123456abcd,12345,abcdef,1234FAA,435612,88975
0123456wxyz,11234,lmnopq,1224FAB,12345,212356

I need to grab all the six fields for file2 when there is a match of first 3 fields of file1 and last 3 fields of file2.

I wrote a small script but seems like it might take days to complete :-)

1 #!/bin/ksh
2
3 while read record
4 do
5 cat file2 | grep "$record" >> final.list
6 done < file1

Can someone help me with a faster solution?

Thanks in advance.

nawk -F',' -f hem.awk file1 file2

hem.awk:

vgersh99,

Linux box does not have nawk.
Has awk and gawk.

'gawk' is your new friend.

vgersh99,

The following ran for about 45-50 minutes and completed, but the output file was empty.
Could you please give me more insight on what is happening below?

Thanks

gawk -F',' -f hem.awk file1 file2 > final.list

hem.awk:
FNR==NR { f1[$0]; next}
( $(NF-2) FS $(NF-1) FS $(NF) ) in file1

ShellLife,

The egrep command ran over an hour and killed it.
I kicked it off again to see how long it runs.

Thanks

Try this:
cat file1 | while read line
do
grep $line file2 >> file3

done