Diffing files by extension.
A long type ago I faced this problem while dealing with kernel. You
edit some files than ran diff -Nurp A/ B/ but B was compiled and
you get a lot of trash in the output.
You may also crossed this question at Stack Overflow. If you read carefully you may notice that there is an answer of mine there. I take the harder path and patched diff. Sadly the diff team reject my patch you can take a look at the thread here.
But happily Andreas Grünbacher, gift us with a nice trick and here it is:
find a/ b/ -type f -printf "%P\0" | sort -zu | xargs -0 -n1 -i% diff -Nu a/% b/%
Here a/ and b/ are the original and patched tree, respectively. -printf "%P\0" will
print the relative file names delimited by null characters: \0. The sort options
are to handle the null delimited and remove duplicates, unique. xargs options
are -0 handle null delimited, -n1 is to limit arguments, -i% is to use % as
a placeholder for the argument and diff -Nu is to treat handle new files and include
context at the diff output. So basically this is find all files at this two trees, order and
unique than, and show the diference for each one.. To filter this by extension is just a matter
of filtering at the find command, so for C source and header files:
find a/ b/ -type f -name '*.[hc]' -printf "%P\0" | sort -zu | xargs -0 -n1 -I% diff -Nu a/% b/%
The -I option of xargs is deprecated in Linux but more portable than -i in lowercase. This is
because the FreeBSD xargs for example doesn’t have lowercase -i.
I hope this helps as helped me. Thank Andreas!
Cheers!