Read two files, if duplicate found ignore, otherwise print 2

[hsemple]

Hi,

I have 2 data files that contain 2 days worth of transactions. For example File1 contains Mon & Tues data and File2 contains Tues & Wed data. There will be some additional Tues records in File2 that were not in File1 due to the time that the file was created.

I need to be able to read the two files and compare File1 with File2. I need to print (to an output file)only the records in File2 that do not appear in File1.

 

[vgersh99]

man comm

vlad
+----------------------------+
| #include<disclaimer.h> |
+----------------------------+

 

[xmb]

If you wanna compare whole lines and not just some parts, that will do for totals: awk '! Seen[$0]++' file1 file2
Basically, awk 'BEGIN { while (getline <"file1") Seen[$0]=1 } ! Seen[$0]' file2

. Mac for productivity
.. Linux for developement
... Windows for solitaire

 

[futurelet]

Lines are printed if
1. They are in the 2nd file; and
2. they weren't in the first file.

NR==FNR { a[$0];next }  # First file.
!($0 in a)              # Second file.

 

[hsemple]

futurelet,

Thanks for the response, however, when I tried your code it didn't work out as I had expected.

I added the code to my unix script but the output file that gets created is the same as the $histfile, it doesn't pick out the unique records:

# First line reads first file.
# Second line compares to second file.
# If the record is in the second file but not in the first file then the record is printed.
awk '
NR==FNR
{a[$0];next}
!($0 in a)
' $histfile $datafile > $datafile.bak

 

[PHV]

awk '
NR==FNR{a[$0];next}
!($0 in a)
' $histfile $datafile > $datafile.bak

Hope This Helps, PH.
Want to get great answers to your Tek-Tips questions? Have a look at FAQ219-2884 or FAQ222-2244

 

[futurelet]

Not
[tt]
NR==FNR
{a[$0];next}
[/tt]
but
[tt]
NR==FNR {a[$0];next}
[/tt]
You changed the code.

 

[hsemple]

Thanks to Futurelet and PHV for setting me straight on that one line of code that I had messed up by splitting it up! It works fine now.

 

[vgersh99]

that's a rare site to have both of you guys thanked in the same sentence

congrats!

vlad
+----------------------------+
| #include<disclaimer.h> |
+----------------------------+