UNIX for Dummies Questions & Answers

Hi,

Please help me, I have two files. I need to output the difference of contents of each file in another file. For example, I need to know the content of the file1 that does not exist on file2 and vice versa. Please take note that the size of the files are large. How can I do it using unix command or a unix script? Thanks in advance!

You can do something like this:

Code:

#!/bin/sh

rm diff1 diff2

while read line; do
  grep "$line" file2 > /dev/null 2>&1
  case $? in
     1) echo "$line" >> diff1 ;;
  esac
done < file1

while read line; do
  grep "$line" file1 > /dev/null 2>&1
  case $? in
     1) echo "$line" >> diff2 ;;
  esac
done < file2

Or:

Code:

diff file1 file2|awk '/^</{print $2 > diff1}/^>/{print $2 > diff2}'

The differences are in the files diff1 and diff2.

Regards

If your shell supports process substitution:
(use nawk or /usr/xpg4/bin/awk on Solaris)

Code:

paste <(awk 'NR==FNR{f1[$0];next}!($0 in f1)' file1 file2) \
<(awk 'NR==FNR{f2[$0];next}!($0 in f2)' file2 file1)

man comm

csh:
a simple "diff file1 file2 > file3" would do.

Differences will be in file3 with arrows pointing to which file difference was found.

example:

% diff awe_parse AWE_parse
17,20c17
< echo "Parsing: ${AWEDIR}/${FILE} file"
<
< sed -e 's/[0-9]TRUE/ TRUE/g' -e 's/[0-9]FALSE/ FALSE/g' ${AWEDIR}/${FILE} > ${AWEDIR}/${NEWFILE}
<
---
> echo "AWE file: ${AWEDIR}/${FILE} found"
%

Some contents were found in first file that are not in 2nd file. Same for 2nd file.