make diff to ignore symbolic link

Question

My project has the following structure

/project/config.mk
/project/dir1/config.mk -> ../config.mk
/project/dir2/config.mk -> ../config.mk

When I used diff to create the patch file, the /project/config.mk was done correctly, but the two symbolic links got some problems. They were both treated as new files, the diff sections were the whole content of the config.mk file. I tried to find a diff option to disable following symbolic link, but there is no such option available. Any suggestions are appreciated.

As Overbose's suggestion, I create this script. It works. Thank everyone for taking time answering.

#!/bin/sh -v
ori_dir=$1
new_dir=$2
patch_file=./patch_file
if [ -f ${patch_file} ]
then
        rm ${patch_file}
fi
ori_files=`cd ${ori_dir} ; find ./ -type f ! -type l`
for i in ${ori_files} ; do 
        if [ -f ${ori_dir}/$i ] 
        then
                if [ -f ${new_dir}/$i ]
                then
                        diff -rup ${ori_dir}/$i ${new_dir}/$i >> ${patch_file}
                fi
        fi
done

Solution 1

Use find in the following way:

find . ! -type l

This option should skip following symbolic links. Use that command to locate your file before running diff.

Solution 2

In GNU diff v3.3 there is now an option --no-dereference that does the trick

Solution 3

If you add lines like:

dir1/config.mk
dir2/config.mk

to a file .ignore-diff

then you can execute diff(1) like this:

diff -ur -X .ignore-diff